Nuclear Grade HEPA Filters - Flanders/CSC

Nuclear Grade HEPA Filters 

Square, Rectangular, Round and Nipple-Connected 

Filters Constructed and Tested in Accordance with 

• ASME AG-1 

• IEST-RP-CC001.4 Type B 

• MIL-STD-282 

• DOE-STD-3020-2005 

Flanders Filters, Inc. 

A Wholly Owned Subsidiary of Flanders Corporation 

Nuclear Grade 

HEPA Filters 

PB-2016-0907

Quality Assurance 

Any industry with dangerous process or exhaust 

gases and/or particulates has a vital concern 

for the health and safety of personnel. In addition 

to corporate concern, the United States 

Government has dictated that safety equipment 

meets minimum safety standards. Any equipment 

sold to meet these minimum standards must be 

manufactured using accepted Quality Control 

procedures. 

Flanders has developed a Quality Assurance 

program to assure the product or service meets 

these standards. This program addresses the entire 

range of Flanders involvement, including the 

purchase of raw materials, the shortage of these 

raw materials, incorporation of these materials 

into a product or service, testing this product or 

service, then, shipping to its destination. 

The Flanders Program has been audited many 

times, and each time the program has been accepted. 

An uncontrolled copy of the program 

manual is available with each request for Quality 

Assurance information. Like any dynamic document, 

the manual is continually being revised to 

include recent issues of standards and specifications 

in order that Flanders may use the latest 

state-of-the-art methods in providing its products 

and services. 

Quality Assurance Program 

© COPYRIGHT 2007 By 

Flanders/FFI Corporation 

531 Flanders FIlters Road • Washington, NC 27889 

The Quality Assurance Program at Flanders Filters 

has been audited and approved numerous times 

by the Nuclear Utilities Procurement and Inspection 

Committee, NUPIC. This committee was 

established by nuclear electric utilities to ensure 

that suppliers of goods and services meet all applicable 

regulatory and quality requirements. 

Notes: 

1. As part of our continuing program to improve 

the design and quality of all our products, we 

reserve the right to make such changes without 

notice or obligation. 

2. Flanders, through its limited warranty, guarantees 

the products described herein will meet all 

specifications agreed to by the buyer and the 

seller. 

3. ASME N509 Nuclear Power Plant Air Cleaning 

Units and Components. 

4. ASME N510 Testing of Nuclear Air Treatment 

Systems. 

5. ASME AG-1 Code on Nuclear Air and Gas 

Treatment

Nuclear Grade HEPA Filters 

NOTICE . . . Compliance with installation and operation 

standards must be met to ensure quality performance. 

HEPA filters are factory tested to meet the 

requirements of IEST-RP-CC001.4 filters 

Test results appear on both the filter label 

and the filter carton label. An additional 

quality assurance test report is kept on 

file and is available on request. 

Flanders Filters, Inc. (FFI) recommends 

that all HEPA filters be tested in place by 

qualified personnel to ensure that the filters 

have been correctly installed in the 

containment housing. 

Flanders/FFI service personnel are available 

for installations, supervision of installation, 

testing and certification of 

compliance to industry and government 

standards and instruction of the owner’s 

personnel in testing and maintenance 

procedures. 

Flanders/FFI does not guarantee that 

its equipment will operate at the performance 

levels given on the identfication 

labels or in the catalog specfications 

under all conditions of installation 

and use, nor does Flanders/FFI guarantee 

the suitability of its product for 

the particular end use which may be 

contemplated by the buyer. 

For best results, it is recommended 

that the buyer supply complete information 

about the operating conditions 

of the ventilation system to Flanders/ 

FFI for evaluation. 

When the system components are 

supplied to the buyer or his agent for 

final installation and assembly in the 

field, it should be under the supervision 

of factory trained personnel. 

Failure to adhere to this recommendation 

or failure of the buyer to have filters 

timely retested and serviced will 

nullify or limit any warranties which 

might otherwise apply and may result 

in a compromised installation. 

IMPORTANT MESSAGE 

3

Nuclear Grade HEPA Filters - Table of Contents 

4 

Quality Assurance .........................................................................................Inside Front Cover 

Important Message ...................................................................................................................3 

General Information ..................................................................................................................6 

Comprehensive Factory Testing ......................................................................................6 

Retesting by DOE Filter Test Facility ..............................................................................7 

Design Qualification Tests ..............................................................................................7 

Seismic Qualification ......................................................................................................7 

Testing Service Available ...............................................................................................8 

Filter Design and Construction ...............................................................................................8 

Filter Medium .................................................................................................................8 

Two Types of Filter Pack Designs ..................................................................................8 

Sealants/Adhesive ..........................................................................................................9 

Case Material .................................................................................................................9 

Case Styles ....................................................................................................................9 

Faceguards ....................................................................................................................9 

Filter Selection ........................................................................................................................10 

Underwriters Laboratory UL 586 ..................................................................................10 

Filter Selection ..............................................................................................................10 

Standard Sizes and Capacities SEpArATOrlESS ® Filters ................................................11 

Standard SEPARATORLESS ® Filters ...........................................................................11 

Chart: Gel Seal Filters ..................................................................................................11 

Chart: Gasket Seal Filters ............................................................................................11 

SEpArATOrlESS ® Media packs .........................................................................................12 

Standard Sizes and Capacities ....................................................................................12 

Diagram: Dimension ....................................................................................................12 

Chart: 11-inch SEPARATORLESS ® Filter Element .......................................................12 

Chart: 4-inch SEPARATORLESS ® Filter Element .........................................................12 

Standard Sizes and Capacities Separator-Type Filters .....................................................13 

Chart: Gel Seal Filters ..................................................................................................13 

Chart: Gasket Seal Filters ............................................................................................13 

Chart: 11-inch Separator-Type Filter Element ..............................................................14 

Chart: 5 1/2-inch Separator-Type Filter Element .........................................................14 

Chart: 2 3/4-inch Separator-Type Filter Element .........................................................14 

High Temperature Sealant .....................................................................................................15 

Separator-Type Filters ..................................................................................................16 

Supply or Exhaust Air 500ºF Gasket Seal or 390ºF Gel Seal ......................................16 

Chart: Separator-Type Filters Gel Seal and Gasket Seal .............................................16 

Exhaust Air Only 1000ºF ...............................................................................................16 

Chart: Separator-Type Filters Gasket Seal Only ..........................................................16

Nuclear Grade HEPA Filters - Table of Contents 

round Filters ...........................................................................................................................17 

Diagram: Flanges ........................................................................................................17 

Chart: SEPARATORLESS ® Filters, Standard Sizes ......................................................17 

Chart: Separator-Type Filters .......................................................................................17 

Gel Seal ........................................................................................................................18 

Gasket Seal ..................................................................................................................18 

Lifting Bails ...................................................................................................................18 

Faceguards ..................................................................................................................18 

Drilled Flanges ..............................................................................................................18 

UL 586 ...........................................................................................................................18 

Model Numbers and Specifications .............................................................................18 

Nipple-Connected Filters .......................................................................................................19 

Chart: N1 or N2 Filters with SEPARATORLESS ® Filter Elements, Standard Sizes ......19 

Chart: N1 or N2 Filters with Separator-Type Filter Elements, Standard Sizes ............19 

Design Features and Options ................................................................................................20 

Roughing Prefilter .........................................................................................................20 

Diagram: Prefilter ..........................................................................................................20 

Gasket Seal (N1 Filters Only) ........................................................................................20 

Diagram: Wood Case or Metal Case ............................................................................20 

Drilled Flanges ..............................................................................................................20 

Diagram: Nipple-Connected Flange .............................................................................20 

Diagram: Filter Face Flange .........................................................................................20 

Slip-On Flanges ............................................................................................................20 

Faceguards ..................................................................................................................20 

UL 586 (N1 and N2 Filters) ...........................................................................................20 

Model Numbers and Specifications .............................................................................20 

Model Number Designating Development ...........................................................................21 

Filter Model Number .....................................................................................................21 

To Order .......................................................................................................................21 

Nuclear Filter Size Designators ....................................................................................21 

Chart: Standard Size Designator ..................................................................................21 

Model Number Designating Chart .......................................................................................22 

Suggested Specifications ......................................................................................................23 

Environmental Condition .......................................................................................................24 

Packaging and Palletizing ............................................................................................24 

Diagram: Vertical Pleats ................................................................................................24 

receipt, Storage, Shelf life ...................................................................................................25 

Shelf Life Information ...................................................................................................25 

BlU-JEl ® Seal Data ...............................................................................................................26 

5

Nuclear Grade HEPA Filters: General Information 

Quality Assurance 

The Quality Assurance Program of Flanders Filters, 

Inc. (FFI) meets or exceeds the basic requirements 

of ASME NQA-1 and 10CFR50 APPENDIX B. 

Comprehensive Factory Testing 

Nuclear Grade HEPA Filters meet the requirements 

for performance, testing and construction 

specified in Section 4.2.2 of IEST-RP-CC001.4 

for Type B HEPA filters. This section describes 

performance levels and states, “A filter that has 

been tested for overall penetration at rated flow 

and at 20% of rated flow, in accordance with 

Section 9.1.1 (Mil Std-282). The minimum filter 

efficiency of encapsulated filter in this type is 

99.97% on 0.3µm particles.Every FFI Nuclear 

Grade HEPA filter is factory tested for penetration 

and resistance to airflow at 100% of its rated air 

flow prior to shipment. These values are recorded 

on a barcoded serialized label that is applied to 

each filter. Additionally, filters rated at 75 cfm and 

greater are factory tested for penetration at 20% of 

rated airflow. (This test is commonly known as the 

two-flow test.) The maximum penetration allowed 

at either flow is 0.03%. In recent years, HEPA filter 

designs exceeding the original test methods for 

flow capacities have been developed. Therefore, 

Flanders uses one of two test methods to ensure 

the performance of Nuclear Grade Filters. They 

are described as follows: 

6 

The test method historically specified and use 

by Flanders for most Nuclear Grade filters is 

Mil-Std-282 (method 102.9.1). In this test an 

approved aerosol is used to generate a nearly 

monodisperse aerosol of approximately 0.3 micrometer 

diameter droplets. The penetration of 

the aerosol through the filter is measured with 

forward light scattering photometer. The measuring 

instrument specified by Mil-Std 282 is a 

Q-107 penetrometer. It was originally developed 

by the U.S. Army prior to 1950. The measuring 

instrument is limited by design to testing at flows 

ranging from 15 cfm to 1100 cfm. Flanders uses 

this instrument for all Nuclear Grade filters with 

rated air flows ranging from 15 cfm to 1100 cfm. 

For filters rated below 75 cfm, the 20% flow test 

cannot be performed accurately. 

FFI Nuclear Grade Filters are produced in square, 

rectangular, and nipple-connected designs.

HFATS Test 

Los Alamos National Laboratory developed an 

alternate test method in the 1980’s under contract 

to the U.S. Department of Energy (DOE). 

It is often referred to as the HFATS test (High 

Flow Alternative Test System). It was developed 

specifically to test filters rated at airflows higher 

than 1100 CFM, but it can be used for lower 

flows. It is only limited by the size of the system 

fan and the aerosol generator output. This method 

was later standardized in the publication of a 

recommended practice, IEST-RP-CC007.1, Testing 

ULPA Filters, published by the Institute of 

Environmental Sciences and Technology. Currently, 

ASME AG-1 Section FC allows for testing 

by this method. The filter is challenged with an 

acceptable polydispersed oil aerosol and the 

penetration through the filter is measured with 

a Laser Particle Counter. The Particle Counter 

counts and sizes individual droplets in a size 

range from 0.1 to 3.0 micrometers in diameter. 

The ratio of the downstream counts to the upstream 

counts in each size range is the penetration. 

Although this value is not equal to the 

penetration measured by the Q-107, research 

performed by Los Alamos National Laboratory 

verified it to be very similar and the method to 

be an acceptable alternative to the penetration 

measured by Mil-Std-282 Test Method. 

Since this system measures the penetration in 

each size range, and a HEPA filter penetration 

varies with particle size, the maximum allowable 

penetration is 0.03% for the most penetrating 

particle size (MPPS). Flanders Filters Inc. can 

use this system to test filters that are rated at 

flows higher than 1100 CFM, if specified by the 

customer. 

retesting by DOE Filter Test Facilities 

DOE requires that nuclear facilities operated by 

DOE contractors have their HEPA filters retested 

at a Filter Test Facility operated for DOE. This 

service must be arranged by the buyer. Filters 

rejected at the test station as not conforming to 

Nuclear Grade HEPA Filters: General Information 

the purchase specifications and determined not 

to have been damaged in shipment, will be replaced 

at no cost to the buyer. Filters must be 

shipped directly from the factory to the retest 

facility. If filters must be shipped to the retest 

facility, the requirement must be specified when 

quotations are requested. Filters requiring test 

will be quoted and sold to end user only. Upon 

successfully passing the testing at the retest facility, 

filters become the property of the end user 

or buyer. The end-user or buyer must arrange 

for their transport from the retest facility to the 

end-user’s site. 

Design Qualification Tests 

Design qualification testing is a key element of 

Nuclear Grade filters. Since there is a wide variety 

of filter types, sizes, and construction materials, 

purchasers shall clearly state required 

design qualification tests within their solicitations.These 

tests may include, but are not limited 

to those specified in ASME AG-1 Section 

FC-5100. Section FC tests are defined only for 

filter sizes specified in Table FC-4110 and may 

not be applicable for round and nippleconnected 

filter designs. AG-1 requires design qualification 

test to be performed by an independent 

laboratory within 5 years prior to shipment. 

Flanders has several models which meet these 

requirements; please consult the factory for the 

latest list of models which do. In addition, Flanders 

has the capability to perform several of 

the FC-5100 qualification tests, in-house, under 

the Flanders quality assurance program. These 

tests may be helpful to the purchaser for qualifying 

designs which do not meet the full requirements 

of ASME AG-1. Please consult the factory 

for assistance in this matter. 

Seismic Qualification 

ASME AG-1 requires filters to be seismically 

qualified per the purchaser specified loadings. 

FFI has qualified various filter models per ASME 

AG-1 Section FC - 4300. The test qualification 

7

Nuclear Grade HEPA Filters: Design and Construction 

was performed as follows: A HEPA filter was installed 

in a Flanders/CSC bag-in bag-out containment 

housing and subjected to simulated 

earthquake loading. No failure or damage was 

observed during or subsequent to the simulated 

event. The load exceeded the current requirements 

for UBC Zone 4 loading. 

Testing Service Available 

Flanders service personnel are available for installation, 

supervision of installation, filter testing 

and certification of compliance to industry and 

government standards, and instruction of the 

owner’s personnel in testing and maintenance 

procedures. Contact the factory for details. 

Filter Design and Construction 

Filter Medium 

The filter medium in FFI’s Nuclear Grade filter 

elements is glass (boron silicate microfiber) 

and contains a waterproofing binder which adds 

strength under both wet and dry conditions. FFI 

manufactures its own filter media to meet or exceed 

the requirements of ASME AG-1 Section 

FC, Mandatory Appendix FC-I. Approved media, 

formulated for resistance to airborne acids, are 

also available; consult the factory. 

Two Types of Filter pack Designs 

Flanders Filters Inc. manufacturers SEPARA- 

TORLESS ® HEPA Filters and conventional Separator-Style 

Filters. In a separator-style pack, the 

filter media is folded over corrugated aluminum 

separators with hemmed edges to separate the 

pleats of the filter pack. 

8 

HEPA Filters SEPARATORLESS ® HEPA filter with a 

formed, self-supporting pack 

Flanders Filters manufactures its own filter media, 

enabling us to develop a unique manufacturing 

process for the production of SEPARA- 

TORLESS ® HEPA Filters. In one manufacturing 

operation, Flanders Filters Inc. produces a selfsupporting 

and self-separating Media Pack. The 

SEPARATORLESS ® Filter offers many advantages 

over conventional separator-style HEPA 

Filters: 

• More usable media area for longer service 

life and higher dust-holding capacity 

• Reduced cost of ownership due to longer 

service life 

• Maximum utilization of the media 

• 11 inches deep SEPARATORLESS ® Pack 

has approximately 400 sq. ft. of media as 

compared to 240 sq. ft. for a conventional 

separator-style filter. 

• Can handle some harsh environments 

which may attack aluminum separators 

• Media pack can be incinerated 

• Media is thicker than conventional media 

used in separator-style HEPA Filters 

Conventional Separator-style HEPA filter with 

aluminum separators

Sealants/Adhesive 

Fire-retardant solid urethane is used to bond the 

filter element to its integral case. Maximum temperature 

rating for this sealant is 250°F. 

Case Material 

Plywood 3 /4 - inch fire-retardant plywood cases are 

ideal for many applications, and are easier to incinerate 

or breakdown for disposal than are metal 

case filters. However, they are not recommended 

for use in systems having high moisture content 

or high temperature: they may warp or support 

biological growth. Stainless steel case materials 

should be used in moisture-laden applications. 

Stainless Steel - 14-gauge Type 409 and 14-gauge 

Type 304 stainless steel cases are available. The 

Type 409 stainless steel replaced cadmium-plated 

and chromized steel. However, Type 409 material 

has a low resistance to caustic atmospheres. Type 

304 stainless steel is recommended for those applications. 

Case Style 

The technique used for sealing the filter in service 

determines the selection of the filter case style. 

(See illustrations.) 

Nuclear Grade HEPA Filters: Design and Construction 

Gel Seal — Metal case gel seal filters have a fabricated 

channel ( 3 /4” wide x 3 /4” deep) located on 

one face. Wood case filters have a routed channel 

( 3 /8” wide x 3 /4” deep) on one face. 

BLU-JEL ® Seal was developed by Flanders and 

is the standard gel seal material. 

Gasket Seal — Metal case gasketed filters are provided 

with flanges for the placement of the gasket 

as specified by the customer. On wooden cases, 

the gasket is applied to the face of the case. 

Gasketed filters for normal service are supplied 

with closed cell sponge neoprene ( 1 /4” x 3 /4”). 

High-temperature filters require the special sealants 

described on page 15. Specify upstream, 

downstream, or both for the location of the gasket 

or gel seal within the model number. 

Faceguards 

The Gel Seal The Gasket Seal 

A knife edge in the filter housing mates into a gel 

filled channel provided on the filter. Flanders invented 

the fluid seal in response to requirements 

for an absolute seal in the most critical applications. 

In most cases, gel seal filters are also easier and 

quicker to change out than gasketed filters. 

Filter 

Gel Seal 

Channel 

Knife Edge 

BLUE-JEL ® Seal 

The standard faceguard materials are 23-gauge 

4 x 4 mesh, welded galvanized dipped steel or 

18-gauge Type 304 stainless steel. Faceguards 

protect the media, but are not a guarantee against 

damage caused by mishandling. 

Note: Specify faceguard location as upstream, downstream 

or both. 

Filter 

Gasket 

Seal 

A filter clamping mechanism is typically used to 

maintain sealing pressure on gasketed filters. 

Gasket seals have a tendency to develop bypass 

leaks, primarily because of compression set. 

9

Nuclear Grade HEPA Filters: Filter Selection 

Underwriters laboratory, Ul 586 

To be UL 586 classified, filters must be submitted 

to Underwriters Laboratories for extensive 

testing including spot flame, and environmental 

exposure to heated air. A UL 586 classification is 

accepted by the DOE as meeting the Heated Air 

and Spot Flame Test requirements in ASME AG-1 

for Nuclear Grade filters. 

UL labels are optional. Some high-temperature 

filters, and filters larger than 24” x 30” x 11 1 /2” , 

are not eligible for UL 586. 

Filter Selection 

1. Standard SEPARATORLESS ® maximum height 

is 24-inches. When specifying a filter size, 

the first dimension is always the height of the 

filter (the dimension parallel to the pleat of the 

medium); the second dimension is always the 

width of the filter; and, the third dimension is 

the filter depth. 

2. The filter sizes in Table FC-4110 do not include 

all sizes offered by manufacturers or requested 

by users today. The table is limited to nine (9) 

sizes, perceived by the American Society of 

Mechanical Engineers (ASME) to be standard. 

For special sizes, not addressed by the table, 

contact the factory. 

3. Of the sizes appearing in Table FC-4110, the 

GG-F (24” x 24” x 11 1 /2”) and GG-D (24” x 24” 

x 5 7 /8 ”) are the largest. Capacities for other 

sizes are computed from one of these two, 

depending on the filter element depth of the 

unlisted filter and its effective face area relative 

to the listed size. (The face area is obtained 

by subtracting two inches from the height and 

width dimensions to allow for the thickness of 

the case and the pack-to-case sealant.) 

4. 11 1 /2” deep filters are generally selected for 

service where a minimum amount of space 

relative to a maximum amount of airflow is 

required. Most often this is required in builtup 

banks, walk-in plenums, or side-access 

housings. Flanders’ GG-F size filter is most 

frequently selected. 

10 

5. If filters are operated at higher flows, efficiency 

can decrease and resistance will increase. 

Care should be taken if the customer is planning 

to operate a filter at higher than the rated 

capacity to determine if hostile environmental 

factors, such as combined high operating flow 

rate, water vapor condensation, and/or acid 

vapors, will cause filter failure. For example, 

water condensate on the filter media could 

plug the element, causing failure. 

A Z-drawing will be developed and become the 

size designator, in the model number for any filter 

which has special construction or testing requirements 

which are not covered in the Style Code 

System. Example: Z07123 

Important Note: 

GG-F filters with SEPARATORLESS ® media packs 

are sold as Size 5, 6 or 7. Unless customer specifies 

to the contrary, the filter is tested and sold as 

Size 5 (1000 cfm @ 1.0” w.g. maximum). 

“T”-clip on alignment mechanism 

(T-clips are factory installed.)

Standard SEpArATOrlESS ® Filters 

Insert the desired Filter Size Designator from 

the charts on page 12 at the end of the model 

number. 

( Example: T-007-W-43-05-NU-51-23-GG-FU5) 

Gel Seal Filters 

Media Pack Depth 

(inches) 

4 

11 

11 

Typical model numbers specifying filters with 

galvanized or stainless steel faceguards on both 

faces and with either BLU-JEL ® Seal or a neoprene 

gasket located on the upstream face are 

addressed below. 

Gasket Seal Filters 

Type 409 S/S T-007-W-42-05-NU-51-13-_ _-FU5 

Type 304 S/S T-007-W-43-05-NU-51-23-_ _-FU5 

3 /4” Fire-Retardant Plywood T-007-W-04-05-NU-51-13-_ _-FU5 

Type 409 S/S T-007-U-42-05-NU-51-13-_ _-FU5 

Type 304 S/S T-007-U-43-05-NU-51-23-_ _-FU5 

3 /4” Fire-Retardant Plywood T-007-U-04-05-NU-51-00-_ _-FU5 

Note: “T” prefix in model number indicates T-clip requirement for gel seal-type filters used in sideaccess 

housings. (See gel seal photo on page 10.) 

Gasket Seal Filters Size, Material and Model Number 


(inches) 

5 1 /2 

11 

11 

Gel Seal Filters Size, Material and Model Number 

Case Filter Material 

Nuclear Grade HEPA Filters: Filter Selection 

Model Number 

(typical) 

Type 409 S/S T-007-D-42-05-NU-51-13-_ _-DU5 

Type 304 S/S T-007-D-43-05-NU-51-23-_ _-DU5 

3 /4” Fire-Retardant Plywood T-007-D-04-05-NU-51-13-_ _-DU5 

Case Filter Material Model Number 

(typical) 

Type 409 S/S 0-007-D-42-03-NU-11-13-_ _-DU5 

Type 304 S/S 0-007-D-43-03-NU-11-23-_ _-DU5 

3 /4” Fire-Retardant Plywood 0-007-D-04-00-NU-11-13-_ _-DU5 

Type 409 S/S 0-007-W-42-03-NU-11-13-_ _-FU5 

Type 304 S/S 0-007-W-43-03-NU-11-23-_ _-FU5 

3 /4” Fire-Retardant Plywood 0-007-W-04-00-NU-11-13-_ _-FU5 

Type 409 S/S U-007-U-42-05-NU-51-13-_ _-FU5 

Type 304 S/S U-007-U-43-05-NU-51-23-_ _-FU5 

3 /4” Fire-Retardant Plywood U-007-U-04-05-NU-51-00-_ _-FU5/ 

11

Nuclear Grade HEPA Filters: SEPARATORLESS ® Filter Selection 

Standard Sizes and Capacities 

Flanders manufactures standard square and 

rectangular Nuclear Grade filters in a variety of 

sizes and capacities. (Sizes and capacities for 

Round and Nipple connected filters are listed 

in their respective sections in this bulletin.) The 

type (SEPARATORLESS ® or Separator-Type) and 

depth of the filter element is a primary factor in 

filter capacity. 

NOTE: The maximum allowable resistance at 

the Nominal Rated Capacity is 1.0-inch w.g. (or 

1.3-inch w.g. for certain sizes listed in ASME 

AG-1, Section FC, Table FC-4110). 

SEPArATorLESS ® Filter Sizes and Capacities 

12 

Filter Size 

(designator) 

SEPArATorLESS ® Filter Sizes and Capacities 

Dimensions 

H W D 

(inches) 

Capacities 

(cfm) 

Maximum Initial 

resistance 

(inches w.g.) 

CC-F 12 12 11 1 /2 200 1.0 

CC-F 12 12 11 1 /2 250 1.3 

CG-F 12 24 11 1 /2 455 1.0 

GC-F 24 12 11 1 /2 455 1.0 

GE-F 24 18 11 1 /2 725 1.0 

GG-F 24 24 11 1 /2 1000 1.0 

GG-F 24 24 11 1 /2 1250 1.3 

GG-F 24 24 11 1 /2 1500 1.3 

GN-F 24 30 11 1 /2 1275 1.0 

Filter Size 

(designator) 

4-inch SEPArATorLESS ® Filter Element 

Dimensions 

H W D 

(inches) 

W 

Capacities 

(cfm) 

H 

Pack 

Dept 

D 


resistance 

(inches w.g.) 

BB-D 8 8 5 7 /8 50 1.3 

CC-D 12 12 5 7 /8 125 1.3 

GE-D 24 18 5 7 /8 375 1.0 

GG-D 24 24 5 7 /8 500 1.0 

GN-D 24 30 5 7 /8 625 1.0

Standard Separator-Type Filters 

Insert the desired Filter Size Designator from the 

charts on page 12 at the end of the model number. 

(The Size Designator indicates whether a 5 1 /2- inch 

or 11-inch filter element is being ordered.) Typical 

model numbers specifying filters with galvanized 

Gel Seal Filters 


(inches) 

5 1 /2 

11 

or stainless steel faceguards on both faces and 

BLU-JEL ® Seal or a neoprene gasket located on 

the upstream face are addressed below. 

Gasket Seal Filters 

Note: “T” prefix in model number indicates T-clip requirement for gel seal-type filters used in 

side-access housings. (See gel seal photo on page 10) 


(inches) 

5 1 /2 

11 

Nuclear Grade HEPA Filters: Separator Filter Selection 

Gel Seal Filters Size, Material and Model Number 


(typical) 

Type 409 S/S T-007-C-42-05-NU-51-13 -_ _- DU5 

Type 304 S/S T-007-C-43-05-NU-51-23 -_ _- DU5 

3 /4” Fire-Retardant Plywood T-007-C-04-05-NU-51-13 -_ _- DU5 

Type 409 S/S T-007-C-42-05-NU-51-13 -_ _- FU5 

Type 304 S/S T-007-C-43-05-NU-51-23 -_ _- FU5 

3 /4” Fire-Retardant Plywood T-007-C-04-05-NU-51-13 -_ _- FU5 

Gasket Seal Filters Size, Material and Model Number 


(typical) 

Type 409 S/S 0-007-C-42-03-NU-11-13 -_ _- DU5 

Type 304 S/S 0-007-C-43-03-NU-11-23 -_ _- DU5 

3 /4” Fire-Retardant Plywood 0-007-C-04-00-NU-11-13 -_ _- DU5 

Type 409 S/S 0-007-C-42-03-NU-11-13 -_ _- FU5 

Type 304 S/S 0-007-C-43-03-NU-11-23 -_ _- FU5 

3 /4” Fire-Retardant Plywood 0-007-C-04-00-NU-11-13 -_ _- FU5 

13

Nuclear Grade HEPA Filters: Standard Separator-Type Filter Selection 

Standard Separator-Type Filter Sizes and Capacities 

14 

Filter Size 

(designator) 

11-inch Separator-Type Filter Element 

Dimensions 

H W D 

(inches) 

Capacities 

(cfm) 


Resistance 

(inches w.g.) 

CC-F 12 12 11 1 /2 200 1.0 

CC-F 12 12 11 1 /2 250 1.3 

CG-F 12 24 11 1 /2 455 1.0 

GC-F 24 12 11 1 /2 455 1.0 

GE-F 24 18 11 1 /2 725 1.0 

GG-F 24 24 11 1 /2 1000 1.0 

GG-F 24 24 11 1 /2 1250 1.3 

GG-F 24 24 11 1 /2 1500 1.3 

GN-F 24 30 11 1 /2 1275 1.0 

Filter Size 

(designator) 

5 1 /2 -inch Separator-Type Filter Element 

Dimensions 

H W D 

(inches) 

Capacities 

(cfm) 


Resistance 

(inches w.g.) 

BB-D 8 8 5 7 /8 50 1.3 

CC-D 12 12 5 7 /8 125 1.3 

GE-D 24 18 5 7 /8 375 1.0 

GG-D 24 24 5 7 /8 500 1.0 

GN-D 24 30 5 7 /8 625 1.0 

Filter Size 

(designator) 

2 3 /4-inch Separator-Type Filter Element 

Dimensions 

H W D 

(inches) 

Capacities 

(cfm) 


Resistance 

(inches w.g.) 

BB-A 8 8 3 1 /16 25 1.3

Standard High-Temperature Filters 

Flanders manufactures HEPA filters for 

applications with high temperature requirements 

up to 1000°F (540°C) for exhaust 

air only and 500°F (260°C) for supply 

air. They do not meet all the qualification 

requirements of ASME-AG1 Section FC. Hightemperature 

filters are available with gasket 

or gel seal. (Filters with BLU-JEL ® Seal have 

a maximum service temperature of 392°F.) 

Gasketed filters for high temperature service 

are supplied with silicone sponge gaskets 

( 1 /4 inch thick x 3 /4 inch wide). High Temperature 

Nuclear Grade HEPA Filters meet the 

requirements of IEST-RP-CC001.4 for Type B 

Filters and are tested in accordance with MIL- 

Std-282. Two types of high temperature HEPA 

filters are offered. The choice should be carefully 

made in accordance with the proposed 

filter service requirements for the specific 

application. 

Silicone Sealant (Designator NE) 

This is a high-temperature room-temperature 

vulcanizing (RTV) silastic-sealant silicone 

compound rated for continuous service up to 

500°F/260°C (supply air). 

NOTE: This high-temperature sealant is UL 586 

classified; however, it does not meet all the qualification 

requirements of ASME-AG1 Section FC. 

“NE” filters are eligible for UL586 labels. 

Glass pack Sealant (Designator NG) 

The glass pack seal is rated for continuous 

service up to 1000°F/540°C in exhaust air applications 

only and with separator-type filter 

elements only. A mat of submicron glass fibers 

creates a seal when compressed between the 

filter pack and filter case. The glass packing is 

not an adhesive seal but a mechanical seal that 

functions much as the glass fiber medium of the 

filter itself. 

Additional angle stiffeners are added to prevent 

the filter pack from slipping at high pressure 

drops. 

Nuclear Grade HEPA Filters: High-Temperture 

NOTE: Labels are not attached to 1000°F high 

temperature filters. 

NOTE: Due to the possibility of the glass pack 

seals shedding glass fibers, the glass pack sealant 

should be used for exhaust systems only. 

NOTES: _____________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

____________________________________________ 

___________________________________________ 

15

Nuclear Grade HEPA Filters: High Temperature 

Supply or Exhaust Air 

500° F Maximum (Gasket Seal) or 390°F 

Maximum (Gel Seal) 

Insert the desired Filter Size Designator from the 

chart on page 14 at the end of the model number. 

Typical model numbers specifying filters with 

16 

Media Pack 

Depth 

(inches) 

5 1 /2 

11 

galvanized or stainless steel faceguards on both 

faces and with BLU-JEL ® Seal (for gel seal filters) 

or silicone sponge (for gasket seal filters) located 

on the upstream face are addressed below. 

Separator-Type Filters, Case Material and Model Number 

Case Filter 

Material 

Type 409 S/S T-007-C-42-05-NE-51-13-_ _-DU5 0-007-C-42-03-NE-31-13-_ _-D 

Type 304 S/S T-007-C-43-05-NE-51-23-_ _-DU5 0-007-C-43-03-NE-31-23-_ _-D 

Type 409 S/S T-007-C-42-05-NE-51-13-_ _-FU5 0-007-C-42-03-NE-31-13-_ _-F 

Type 304 S/S T-007-C-43-05-NE-51-23-_ _-FU5 0-007-C-43-03-NE-31-23-_ _-F 

Exhaust Air Only - 1000° F Maximum 

Media Pack 

Depth 

(inches) 

5 1 /2 

11 

Model Number 

Gel Seal 

(Max. 390° F, 200° C) 

Separator-Type Filters Only 

Case Filter 

Material 

Model Number 

Gasket Seal 

(Max. 390° F, 200° C) 

Type 409 S/S 0-007-C-42-03-NG-00-23-_ _-D 

Type 304 S/S 0-007-C-43-03-NG-00-23-_ _-D 

Type 409 S/S 0-007-C-42-03-NG-00-23-_ _-F 

Type 304 S/S 0-007-C-43-03-NG-00-23-_ _-F 

Model Number 

Gasket Seal 

(Max. 500° F, 260° C) 

Note: “T” prefix in model number indicates T-clip requirement for gel seal-type filters used in 

side-access housings. (See gel seal photo on page 10) 

Insert the desired Filter Size Designator, from the charts on page 14, at the end of the model number. 

Model numbers specifying filters with stainless steel faceguards on both faces are addressed below. 

Note: Not available in gel seal. 

NOTE: These filters are shipped without gaskets, since none of 

the standard gasket materials are rated for 1000°F service. However, 

two woven glass gaskets may be provided with the filter if 

requested. The gaskets are shipped unattached and must be installed 

with the filter. Filter Labels are also shipped unattached.

ound Filters 

Round Nuclear Grade HEPA filters are available 

with Flanders’ SEPARATORLESS ® filter element 

and with separator-type elements. Cases are 

made of 14 gauge Type 304 or Type 409 stainless 

steel, and are available for both gasket or fluid seal 

applications. Round filters are also manufactured 

for high temperature applications. (See page 15 

for information on high-temperature sealants.) 

Round Nuclear Grade HEPA filter components are 

materials specified in ASME AG-1 but the filters 

are not tested for rough handling, wet over pressure, 

or heated air or spot flame as required by 

that specification. Flanders performs acceptance 

testing of penetration and resistance only. 

ro 

(No 

Flange) 

r1 

(Single 

Flange) 

Filter Size 

(designator) 

Filter Size 

(designator) 

X 

Y 

Airflow 

Airflow 

Standard flange placement for a single flange 

rolled filter is upstream. Contact factory for alternate 

placement. 

r2 

(Double 

Flange) 

r5 

(Gel 

Seal) 

SEpArATOrlESS ® Filters Standard Sizes (contact factory for special sizes) 

X 

Dimensions 

Y 

(inches) 

Z 

Nuclear Grade HEPA Filters: Round Filters 

X 

Separator-Type Filters 

Filter Element 

Depth 

(inches) 

Nominal rated 

Capacities 

(cfm) 

Airflow 

Z Z 

X 

Airflow 


resistance 

(inches w.g.) 

Dimensions Filter Element Nominal rated 

X Y Z Depth Capacities 

(inches) 

(inches) 

(cfm) 

B 6 5 /8 8 8 4 35 1.0 

C 10 5 /8 12 8 4 100 1.0 


resistance 

(inches w.g.) 

A 6 5 /8 8 5 1 /4 3 1 /16 20 1.0 

B 6 5 /8 8 8 5 1 /2 35 1.0 

C 10 5 /8 12 8 5 1 /2 100 1.0 

Y 

Y 

X 

X 

17

Nuclear Grade HEPA Filters: Round Filters 

Gel Seal 

Gel Seal filters are supplied with a 5 /8 -inch 

x 11 /16 -inch deep channel on one face only. The 

channel is factory-filled with Flanders’ BLU-JEL ® 

sealant. 

Note: Designate R5 Case Style. Standard channel 

location is upstream. (Face of flange) 

Gasket Seal 

18 

Channel 

Gaskets are made from 1 /4-inch x 3 /4 -inch closed 

cell neoprene material. Gaskets may be located 

on either side of the upstream flange. Contact 

factory for downstream flange location. 

Note: Designate R1 (one flange) or R2 (2 flanges) 

Case Style and specify location of the gasket as 

face of flange, back of flange, face and back of 

flange or faces of both flanges in the model number. 

Detail any special placement requirements. 

Gasket Location 

Face of Flange Back of Flange 

lifting Bails 

Optional lifting bails are available for easy filterremoval 

in special applications. 

Note: Specify the “B” prefix in the filter modelnumber. 

Faceguards 

The standard faceguard materials 

are 23-gauge 4 x 4 

inch mesh, welded galvanized 

dipped steel or 18-gauge Type 

304 stainless steel. Faceguards 



Note: Specify faceguard location as upstream, 

downstream or both. 

Drilled Flanges 

Drilled flanges are available 

as an option. Flanders’ 

standard pattern is 

eight (8) 5 /16-inch diameter 

holes equally spaced 

and centered on a 7 3 /8 -inch diameter bolt circle 

for sizes A and B, or a 11 5 /16 -diameter bolt circle 

for size C filters. 

Note: Use the ‘D’ prefix in the model number. 

Ul 586 

For UL 586 classifiication, filters must be submitted 

to Underwriters Laboratories for extensive testing 

including spot flame and exposure to heated air. 

A UL 586 classification listing is accepted by 

DOE for meeting the Heated Air and Spot Flame 

Test Requirement of Nuclear Grade HEPA filters. 

NOTE: UL labels are optional and are applied only 

if specified by the buyer. 

Model Numbers and Specification 

Note: To write a specification for Round Filters, use 

the Designating Charts on pages 21 and 22 for determining 

the model number. Fill in the numbered 

locations in the Suggested Specification Text on 

page 23 with the model number and other appropriate 

selections from the listing on page 17.

Nipple Connected Filters 

Nipple Connected Nuclear Grade HEPA filters are 

available with one (N1) or two (N2) nipple connections, 

and with SEPARATORLESS ® or separatortype 

filter elements. Case materials are 14-gauge 

Type 304 and 14-gauge Type 409 stainless steel 

and 3 /4 - inch fire retardant plywood. High temperature 

models are also available. (See page 15 for 

information on sealants.) Nipple-Connected filters 

are made of materials specified in ASME AG-1 but 

are not tested for rough handling, wet over pres- 

N1 Filters 

Typical Metal Case Filter Illustrated 

X 

H 

W 

Filter Size 

(designator) 

BB-D 8 8 10 8 8 14 4 3 1 1 /2 50 1.3 

CC-D 12 12 12 12 12 18 4 4 1 1 /2 125 1.3 

CC-F 12 12 16 12 12 20 11 4 1 1 /2 200 1.0 

CC-F 12 12 16 12 12 20 11 4 1 1 /2 250 1.3 

GG-D 24 24 12 24 24 14 4 12 4 500 1.0 

GG-F 24 24 16 24 24 20 11 12 4 1000 1.0 

GG-F 24 24 16 24 24 20 11 12 4 1250 1.3 

GG-F 24 24 16 24 24 20 11 12 4 1500 1.3 

Filter Size 

(designator) 


H W D 

(inches) 


H W D 

(inches) 

Nuclear Grade HEPA Filters: Nipple Connected Filters 

Air Flow 

Filter 

pack 

D 

Z 


H W D 

(inches) 


H W D 

(inches) 

Y H 

sure, or heated air or spot flange as required by 

that specification. Flanders performs acceptance 

testing for penetration and resistance prior to attachment 

of cover plates. 


Typical Wood Case Filter Illustrated 

X Z 

X Y Z 

(inches) 

X Y Z 

(inches) 

W D 

Nominal Rated 

Capacity 

(cfm) 

Nominal Rated 

Capacity 

(cfm) 

Air Flow 

Filter 

pack 

N1 or N2 Filters with SEpArATOrlESS ® Filter Elements, Standard Sizes 

Max. Initial 

Resistance 

(Inches w.g.) 

N1 or N2 Filters with Separator-Type Filter Elements, Standard Sizes 

Max. Initial 

Resistance 

(Inches w.g.) 

BB-A 8 8 8 8 8 12 3 1 /16 2 1 1 /2 25 1.3 

BB-D 8 8 10 8 8 14 5 1 /2 3 1 1 /2 50 1.3 

CC-D 12 12 12 12 12 18 5 1 /2 4 1 1 /2 125 1.3 

CC-F 12 12 16 12 12 20 11 4 1 1 /2 200 1.0 

CC-F 12 12 16 12 12 20 11 4 1 1 /2 250 1.3 

GG-D 24 24 12 24 24 14 5 1 /2 12 4 500 1.0 

GG-F 24 24 16 24 24 20 11 12 4 1000 1.0 

Note: Standard Nipple-placement for N1 Filter is downstream. Contact factory for alternate placement. When 

ordering N1 or N2 filters, specify size of nipple connections if Flanders’ standard sizes (see “Y” dimension) are 

not appropriate for your application. 

Y 

19

Nuclear Grade HEPA Filters: Design Features and Options 

Roughing Prefilter 

The case depth dimension of N1 filters may be 

extended 2-inches to accommodate a roughing 

prefilter. Indicate the ‘P’ prefix in the model number 

to specify this option. A special size designator is 

required. Contact the factory for details. 

Note: Prefilter must be shipped loose for UL 586 

listed units. 

20 

Prefilter or Prefilter 

Gasket Seal 

Gaskets are made from 1 /4 -inch thick x 3 /4 -inch 

wide closed cell neoprene material. Specify location 

of the gasket as upstream or downstream, in 

the filter model number. 

Wood Case 

Drilled Flanges 

Metal Case 

Standard flanges may be located on the open 

face or on the nipple connection. These flanges 

may be drilled in a standard pattern or according 

to customer specifications. 

Air Flow 

Nipple-Connection Flange 

Filter Face Flange 

Air Flow 3/4 inch 

Single-Turn 

Flange 

Flanders’ standard patterns are as follows: 5 /16 -inch 

diameter holes equally spaced and centered on the 

filter face flange, or equally spaced and centered 

on the nipple-connection flange. 

Slip-On Flanges 

Optional 150 pound slip-on flanges for pipe nipple 

connections shall be available in Type 304 stainless 

steel, and in any standard IPS size. Note: 

Other sizes and types of flanges are available per 

customer specifications. 

Faceguards 

The standard faceguard materials are 23-gauge 

4 x 4 mesh, welded galvanized dipped steel or 

18-gauge Type 304 stainless steel. Faceguards 



Note: Specify faceguard location as upstream, 

downstream or both. 

Ul 586 (N1 and N2 Filters) 

To be UL 586 classified, filters must be submitted 

to Underwriters Laboratories for extensive testing 

including spot flame and exposure to heated air. A 

UL 586 listing is accepted by DOE for the Heated 

Air and Spot Flame Test Requirement of Nuclear 

Grade HEPA Filters. UL labels are optional and 

are applied only if specified by the buyer. 


Note: To write a specification for Nipple-Connected 

Filters, use the Designating Charts on pages 21 

and 22 to determine the model number. Fill in the 

numbered locations in the Suggested Specification 

text on page 23 with the model number and 

other appropriate selections from the listing on 

page 12 for SEPARATORLESS® or page 14 for 

Separator-type. 

Note: Nipple-connected filters are not intended 

to serve as containment housings.

Model Number Development 

The Filter Model Number 

The design and construction of Flanders’ Nuclear 

Grade HEPA Filters are coded within the filter 

model number, which contains the following information: 

Hardware—Clips, handles, bails, etc. 

Filter Medium—Standard or acid resistant. 

Pack Type—SEPARATORLESS ® or separatortype. 

Case Material—Stainless Steel or wood. 

Case Style—Gel or Elastomer gasket seal designs. 

Sealant—Material used to seal pack to case 

Gasket Type/Location 

Faceguard Type/Location 

Filter Size Code 

UL Code—For filters requiring UL labels. (standard 

size filters only.) For odd size or filters requiring a 

“Z” drawing, the UL Code must be specified separate 

from the filter Model Number. 

Example: 

To order: 

Specify the desired filter: Refer to the model 

number charts in this bulletin and/or to the Model 

Number Designating Chart on page 22. Separately 

list and explain any required options or any requirements 

not addressed by the filter model number. 

Nuclear Filter Size Designators 

Standard Size Filters are designated using the following 

Alphanumeric Code for the Height, Width 

and Depth of the Filter: 

Standard Size Designator 

Height and Width 

Designators 

(inches) 

B = 8 A = 3 1 /16 

C = 12 D = 5 7 /8 

E = 18 D2= 7 7 /8 

G = 24 F = 11 1 /2 

N = 30 F2 = 13 1 /2 

U = 11 3 /8 

Y = 23 3 /8 

Example: 

GG-F = 24” H x 24” W x 11 1 /2 D 

Depth 

(inches) 

T - 007 - U - 43 - 05 - NU - 51 - 23 - GG - FU5 

Hardware 

Filter Medium 

Pack Style 

Nuclear Grade HEPA Filters: Model Number Development 

Case Material 

Case Style 

Sealant 

Gasket Type/ 

Location 

Faceguard 

Type/Location 

Filter Size 

Code 

UL Code 

21

Nuclear Grade HEPA Filters: Model Number Designating Chart 

22 

Special 

Hardware 

options 

Filter 

Media 

Pack 

Type 

Case 

Material 

Case 

Style 

Pack to 

Case 

Sealant 

Gasket 

Type/ 

Location 

Faceguard 

Material/ 

Location 

Filter 

Size 

UL Code 

None 0 

Lifting Bail (for Round Filters) B 

Drilled Flanges D 

2” Extended Case for Roughing Prefilter P 

Extractor T-Clips for Fluid Seal Filter T 

U-Handles on Wood-frame Filters for Flanders G1- housings 

Non-woven glass paper (boron silicate microfiber) 99.97% minimum 

U 

efficiency 007 

Same as 007, with additional treatment for resistance to HF 003 

Same as 007, with additional treatment for resistance to NHO3 010 

4” deep filter pack (SEPARATORLESS ® ) D 

11” deep Pureform ® DYN-E2 filter pack (SEPARATORLESS ® ) U 

11” deep filter pack (SEPARATORLESS ® ) W 

Pleated flat sheet with corrugated aluminum separators C 

14-gauge Type 409 Stainless Steel (Bolted Construction) 42 


14-gauge Type 304L Stainless Steel (Bolted Construction) 12 


14-gauge Type 316L Stainless Steel (Bolted Construction) 15 

3/4” fire-retardant plywood 04 

‘Box-Type’ Construction (for Wood Filters) 00 

Double-turn Flanges, both Faces (for Metal Filters) 03 

Channel for Gel Seal on One Face (Wood or Metal Filters) 05 

Round Filter with No Flange RO 

Round Filter with One Upstream Flange R1 

Round Filter with Two Flanges R2 

Round Filter with Face Channel for Gel Seal R5 

N1 Filter - One Downstream Nipple Connection N1 

N2 Filter - Two Nipple Connections N2 

Fire-Retardant Solid Urethane NU 

RTV Silastic Silicone for High Temperature Filters NE 

Glass Packing for 1000°F Exhaust Filter NG 

TYPE (1st Box) LoCATIoN (2nd Box) 

0. None 4. Glass packing 

1. Neoprene 5. BLU-JEL ® Seal 0. None 2. Downstream face 

3. Silicone sponge X. (Special Material) 1. Upstream face 3. Both faces 

TYPE (1st Box) LoCATIoN (2nd Box) 

0. None 0. None 2. Downstream face 

1. 23-Gauge Galvanized Steel 1. Upstream face 3. Both faces 

2. 18-gauge Stainless Steel 

X. (Special Material) 

Seven spaces are allotted for filter size codes, although all 

spaces may not be required. Standard size designators 

(GG-F, etc.) are entered flush left, including dashes. Special 

sizes (Alphanumeric Designators and Z-drawings) are entered 

flush left with the prefixes (no dashes) 

G G — F 

EXAMPLE: 

NOTE: UL Code is entered flush left in the remaining boxes. USE this UL Code when applicable: 

U5 for UL 586.(Does not apply for Z-drawings) 

T 

— 

0 0 7 — 

4 — 

4 3 — 

0 5 — 

N U — 

5 1 — 

2 3 — 

U 5

Suggested Specifications 

The filters shall be model *(1) Nuclear Grade as 

manufactured by Flanders Filters, Inc. Washington, 

NC. The filter medium shall be all glass with 

a wet strength, water-repellent binder in accordance 

with ASME AG-1 Section FC, Mandatory 

Appendix FC-I. 

To Specify SEpArATOrlESS ® Filter Element: 

Each filter element shall be constructed without 

the use of spacers of any kind, including separators, 

tape, string or strips of medium, by pleating 

a continuous sheet of a formed, corrugated 

medium back and forth upon itself so that it is 

self-supporting. 

To Specify SEpArATOr-Type Filter 

Element: 

Each filter element shall be constructed by pleating 

a continuous flat sheet of medium over corrugated 

.0015 inch minimum thick aluminum spacers 

whose edges have been hemmed to resist tearing 

the medium at the fold. 

The element shall be permanently bonded to a 

*(2) integral case with a fire-retardant urethane 

sealant. The perimeter of the filter face shall have 

*(3) to seal it to its mounting device in service. 

Construction of the filter shall be in a accordance 

with the essential construction requirements of 

ASME AG-1 (latest issue). 

Each filter shall be tested, while encapsulated, 

for resistance to airflow and penetration in accordance 

with ASME AG-1 Section FC 5200 at the 

nominal rated capacity listed in table FC-4110-1 

and at 20% of that capacity for penetration only 

(filters with rated capacity of 75 cfm or higher). 

The penetration at both flows shall not exceed 

0.03%. (This paragraph may not apply to Round, 

N1 or N2 filters.) 

The HEPA filters shall comply with the performance 

requirements as listed in ASME 

AG-1 Section FC-5200. Each filter and filter 

carton shall bear identical labels indicating 

the filter model number, the serial number, 

Nuclear Grade HEPA Filters: Suggested Specifications 

test air-flow direction and the resistance and 

penetration readings at test flow taken for the 

filter on the manufacturer’s Q107 penetrometer 

or HFATS System. In addition, the manufacturer 

shall provide a filter test report and a Certification 

of Compliance report. 

The manufacturer shall, upon request, submit 

evidence that its filters have been qualified in accordance 

with ASME AG-1 or can reasonably be 

expected to do so. 

Filters that are 24” x 12” x 6” and larger shall be 

packaged one filter per carton. Each filter shall 

be encased in a flanged, tightfitting alignment 

cushion sleeve that fits within the carton, leaving 

a dead-air space on four sides of the filter. The 

top and the bottom of the filter shall be protected 

with a cushion or comparible cushon design to 

avoid the deleterious effects of shock, vibration, 

physical damage, water vapor, salt spray, condensation, 

and weather during shiping, handling, and 

storage. Linerboard cartons shall be strapped to 

a Flanders Type 2 pallet with 3 /8-inch wood facing 

on both faces. 


Fill in the numbered locations on the Suggested 

Specification Text by selecting from the corresponding 

category below: 

*(1) Filter model number 

(See page 22) 

*(2) Case material 

14-gauge, Type 409 stainless steel (bolted) 


14 gauge, Type 304L stainless steel (bolted) 


14-gauge, Type 316L stainless steel (bolted) 

3 /4-inch thick fire-retardant plywood 

*(3) Case style 

No flanges 

Two double turn flanges 

A 3 /4-inch channel with gel sealant 

A single metal-nipple connection 

Two metal-nipple connections 

23

Nuclear Grade HEPA Filters: Environmental Conditions 

Environmental Conditions 

Heat resistance 

In high-temperature applications, filter media will 

exhibit a significant loss of strength after the binder 

burns off. (This normally occurs in the 300°-325°F 

range.) Flanders recommends only separator style 

filters be used in high temperature applications. 

Filters not specifically designed for high temperature 

applications are nevertheless constructed 

from self-extinguishing or noncombustible components 

and will withstand periodic temperatures 

up to continuous 250°F with no noticeable change 

in pressure drop or penetration. However, extended 

service under such conditions can cause 

accelerated aging of organic materials and may 

subsequently contribute to filter failure. 

Humidity and Water resistance 

HEPA filter media will tolerate high humidity (95% 

±5%) and some direct wetting, but excessive 

moisture, either from airborne droplets or condensation, 

can plug the filter and result in failure 

by over-pressure. Wood cases are unsuitable for 

high-moisture conditions, since wood expands or 

warps when wet, and supports biological growth 

under humid conditions. Metal case filters are 

more suitable for moisture laden atmospheres. 

Because aluminum separators can corrode in 

some environments and slough particles downstream 

of the filter, SEPARATORLESS ® filters are 

also recommended for moist conditions, except 

in high-temperature or caustic applications. 

Chemical resistance 

All materials have good resistance to most organic 

solvents and are resistant to many weak organic 

and inorganic alkalies and acids. Exposure to 

acids such as HF, and those with NOx radicals 

occurs in nuclear systems fairly often and with 

varying degrees of impact (HF attacks glass). Information 

about the potential effects of humidity, 

various chemical agents, and heated air, and the 

interrelationship of the construction materials, must 

be determined by the user through testing. 

24 

packaging and palletizing 

The successful delivery of undamaged HEPA filters 

depends largely upon good packaging. Shipping 

damage is minimized by encasing each filter in a 

tight-fitting alignment cushion that is located at its 

top and bottom. This results in a dead-air space 

around the filter to absorb impact. Flanders packages 

Nuclear Grade filters 24” x 12” x 11 1 /2” and 

larger in this manner. 

All filter carton material is tested for strength and 

certified to meet all construction requirements of 

the applicable freight classification. 

Additionally, all Nuclear Grade HEPA filters are palletized 

for shipment in groups of cartoned filters 

stacked side-by-side, with 3 /8-inch wood facing at 

the two most vulnerable ends and the aggregate 

strapped to a wood pallet or crated. 

Installation 

Note 

Pleats 

Vertical 

HEPA filters should be installed with the pleats 

aligned with the vertical axis when the airflow is 

horizontal. This prevents sagging and potential 

tearing of the medium as the filter becomes 

loaded with dust in-service.

eceipt and Storage requirements 

HEPA filters should be stored in their original cartons, 

in an environmentally controlled room.HEPA 

filters should be oriented with their pleats vertical, 

and stacked no more than three (3) cartons high 

unless intermediate bracing or flooring is provided 

to prevent the weight of the upper tier from bearing 

on the lower tier. Unless there is obvious damage 

to the cartons, HEPA filters should not be opened 

prior to use, or removed from shipping pallets or 

skids until immediately before installation. 

Filter storage area should be periodically checked 

to ensure filters are not exposed to detrimental 

conditions. Storage areas should be uncluttered 

and permit easy access to filters. A filter-control 

procedure is suggested for the storage area to 

ensure filters are not removed from the area without 

proper authority, and to prevent improper or 

rejected items from being installed in the system. 

Filters should be moved a minimum number of 

times (receipt inspection, storage and release 

for installation only) and handled in a manner 

that does not damage them or their packaging. If 

wrappings or cartons are removed for receiving 

inspection, they should be replaced and positively 

sealed immediately upon completion of the inspection. 

Receiving and storage personnel shall 

be informed of the necessity of proper handling of 

all components, especially the HEPA filters. Care 

must be taken to ensure the filter medium is not 

touched in anyway. 

Shelf life Information 

Flanders recommends that each filter is stored in 

its original shipping carton to prevent exposure to 

ultra violet rays and possible damage to the filter 

medium. The filter should be stored in a controlled 

area, 0°-120°F, and should not be exposed to 

ozone depleting sources. If these parameters are 

satisfied and storage requirements as detailed are 

maintained, the filter shelf life should be three (3) 

years from elastomer gasket cure date or three 

(3) years from manufacturing date for gel seal 

filters. 

Nuclear Grade HEPA Filters: Receipt, Storage, Shelf Life 

Notes: _________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

_______________________________________ 

25

Nuclear Grade HEPA Filters: Blu-Gel ® Seal Data 

BlU-JEl ® Seal Data Sheet 

The gel seal technique provides a simple solution 

to a problem that has long been associated with 

air filters used in critical applications: bypass leakage 

at the interface of the filter and its housing or 

supporting casework. This bypass can contribute 

to high particle counts in clean rooms and laminar 

flow work areas. 

Bypass leakage occurs primarily where gaskets 

are used to seal filters. Many factors contribute 

to its occurrence: improper gasket joints; mating 

flanges that are not flat or have been distorted 

by clamping mechanisms used to compress the 

gasket; memory loss or aging of the gasket material; 

or, bad seals or welds in the filter mounting 

casework. 

The gel seal technique, first developed and patented 

by Flanders in 1969, succeeds in eliminating 

bypass leakage because it avoids the major 

causative factors: the use of gaskets and the need 

for absolutely flat mating surfaces. The technique 

also eliminates clamping devices and allows easy 

installation and replacement of filters. 

General Description 

Flanders BLU-JEL ® Seal is a unique, ice-blue silicone 

gel specially designed to create and preserve 

an airtight seal between high-efficiency particulate 

air filters and their holding cases or housings. The 

gel is factory-installed and factory cured within the 

perimeter channel of filters designed for gel seal 

applications. The cured gel has the self-healing 

quality of a liquid while retaining the stability and 

non-flow characteristics of a solid. These properties 

are maintained at both high and low temperature 

extremes and are not lost even when aged 

continuously at high temperatures. BLU-JEL ® Seal 

exhibits excellent bonding to many materials. It 

is also highly self-adhesive, allowing knife edges 

to be cleanly withdrawn. The hydrophobic nature 

of the gel makes it ideally suited for applications 

that require long-term sealing against moisture 

and other atmospheric contaminants. 

26 

Temperature range 

The recommended constant operating temperature 

range for BLU-JEL ® Seal is -70°F to +392°F. 

Short terms (1-2 hours) at higher temperatures 

should be limited to 500°F. Exposure to either extreme 

will not alter the properties of the gel when 

returned to ambient temperature. Temperatures 

below -70°F wil increase hardness; the gel will become 

brittle at -90°F and will be prone to cracking 

if subjected to mechanical shock. Continuous exposure 

to temperatures above +392°F will result in 

degradation of the polymer. 

Fire and Explosion Data 

Flash Point: Determined by Cleveland ASTM D92 

Open Cup Method. Result: No flash at 450°F. 

Exposure to Flame 

A flame exposure test evaluating BLU-JEL ® Seal’s 

flammability and self-extinguishing characteristics 

was performed, following the same procedure 

used in the Underwriters UL 94-VO test. The gel 

turned to ash on the outer surface, but the inner 

core remained normal. The gel maintained its 

physical shape and did not run or melt. Based 

upon the testing, it is concluded that BLU-JEL ® 

Seal is a self-extinguishing material that will perform 

its designed function as a filter-to-housing 

sealant until flame impingement totally turns the 

sealant to ash. 

Volatility 

The non-volatile content of BLU-JEL ® Seal, as 

determined by testing 2 grams for 2 hours at 302°F 

(150°C), is 98%. The volatility rate of the gel, measured 

after it has been cured at the factory and is 

ready for shipment, is 0.2%.

Nuclear Grade HEPA Filters: Blu-Gel ® Seal Data 

penetration 

The effect of temperature on the hardness of 

BLU-JEL ® Seal has been tested using a Penetrometer 

test machine. The following results are 

expressed in points of penetration (mm x 10-1) as 

measured by the machine: @-58°F: 35 @+77°F: 

57 @+392°F: 34 

Chemical resistance 

Information on BLU-JEL ® Seal’s resistance to a 

wide variety of oils, fuels, hydraulic fluids, solvents, 

silicone fluid, greases, food products, water 

and steam, acids, bases, salts and other chemicals 

is available from the factory upon request. 

radiation Effects 

The expected radiation resistance of BLU-JEL ® 

Seal is 20 megarads at room temperature, 10 

megarads of radiation at 77°F. Radiation exposure 

at these levels will not affect the sealing properties 

of the compound. Exposure to higher levels of 

radiation and temperature will result in irreversible 

brittleness. Further information on radiation testing 

is available from the factory. 

Non-Nutrient 

BLU-JEL ® Seal is a non-nutrient and will not of 

itself support biological growth. The compound 

does not contain a fungicide. 

27

Important Notice 

For best results in the application of Flanders’ products, it is recommended that the buyer 

supply complete information about the operating conditions of the ventilation system to 

Flanders/FFI for prior evaluation. Flanders/FFI does not guarantee that its equipment 

will operate at the performance levels given on the identification labels or in the catalog 

specifications under all conditions of installation and use, nor does Flanders/FFI guarantee 

that suitability of its product for the particular end use which may be contemplated 

by the buyer. When the system components are supplied to the buyer or his agent for 

final installation and assembly in the field, it should be under the supervision of factory 

trained personnel who are equipped to test the installation and certify its performance 

and conformance to industry accepted specifications. Failure to follow these procedures 

may result in a compromised installation. 

F O R E M O S T I N A I R F I L T R A T I O N 

Flanders Filters, Inc. 

531 Flanders Filters Road 

Washington, North Carolina 27889 

Telephone: 252-946-8081 

Toll Free: 1-800-637-2803 

Fax: 252-946-3425 

Website: www.flanders-ffi.com 

Representatives of Flanders/FFI products are located 

throughout the world. 

Your closest representative’s office may be found by 

contacting our manufacturing and sales department. 

Represented by: 

Flanders/FFI Printed in USA 09/2007 

Flanders Filters continues to research and develop product improvements and reserves the right to change product designs and specifications without notice.

Nuclear Grade HEPA Filters - Flanders/CSC

Create successful ePaper yourself

Delete template?

Save as template?