Worm & Bevel Gear Operators - Pro-Tech Valves

Worm & Bevel Gear Operators 

A Zy-Tech Global Industries Product

Another quality product from Zy-Tech Global Industries, Inc. 

Zy-Gear gear operators are designed for long 

lasting dependable service in oil & gas and industrial 

actuation applications. For years project 

managers and engineers have specified and 

relied upon Zy-Gear and other quality 

Zy-Tech flow control products for 

petroleum refining, chemical processing, 

power generating, pulp 

and paper, water treatment and 

other processing facilities located 

throughout the world. 

The Zy-Gear product line offers a worm or bevel 

gear model for applications where dependable, 

accurate actuation is required. The Zy-Gear 

product offering has been computer designed, 

manufactured and tested to provide 

smooth, dependable gear operation 

for many years. 

Contents 

3 Zy-Gear Product Range 

Quick Reference Guide 

4 Worm Gear Standard Features 

5-9 Worm Gear Engineering Data 

10 Bevel Gear Standard Features 

11-13 Bevel Gear Engineering Data 

14 Specifying Zy-Gear 

Figure Numbers 

14 Zy-Gear Technical 

Formulas 

15 Zy-Gear Installation 

And Maintenance 


All Zy-Gear gear operators conform to all applicable 

recognized standards and can be custom 

designed to meet your project requirements. 

Specify Zy-Gear gear operators for all 

your actuation applications and 

you’ll experience first hand what 

Zy-Tech dependability really means. 

Visit our website to learn more 

about Zy-Gear and Zy-Tech Global 

Industries other flow control products. 

Zy-Gear is available in worm 

gear driven models for all your 90 

degree turn requirements and bevel gear 

driven models for multi-turn applications. All Zy-Gear 

gear operators can easily be fitted for motorized operation.

Zy-Gear Product Range Quick Reference Guide 

Worm Gear Operator Range and Specifications 

Gear Maximum Travel at Gear Number Mechanical Maximum Mount. Patt. Minimum Maximum Approx. 

Code Output Both Ends Ratio of Turns Advantage Round Bore Straddle Mounting Mounting Wt. w/o 

Torque to Close and Keyway Centerline Pattern Pattern Handwheel 

MSS-SP 101 

(Pg. #) (ft. lb.) (Degree) (+/-10%) (in.) (in.) (in.) (in.) (lb.) 

WG008 1160 90 +/ -5 50:1 12.5 14.5 Ø 2.13 F14, (4) 3.68 6.43 31 

(Pg. 4) 

1 /2 x 3 /8 key 5 /8 - 11 UNC 

ON 5.50 B.C. 

WG108 1500 90 +/ -5 72:1 18.5 14.9 Ø 2.50 FA16, (4) 4.43 8.86 44 

(Pg. 5) 5 /8 x 7 /16 key 3 /4 - 10 UNC 

ON 6.50 B.C. 

WG208 3300 90 +/ -5 68:1 17 18.4 Ø 3.43 FA19, (8) 6.25 10 88 

(Pg. 6) 7 /8 x 5 /8 key 5 /8 - 11 UNC 

ON 7.50 B.C. 

WG308 9800 90 +/ -5 275:1 68.75 56.7 Ø 4.31 FA25, (8) 7.38 11.81 201 

(Pg. 7) 1 x 3 /4 key 5 /8 - 11 UNC 

ON 10.00 B.C. 

WG408 32,000 90 +/ -5 700:1 175 142.4 Ø 6.25 FA35, (8) 9.75 14 443 

(Pg. 8) 1 /2 x 1 key 1- 8 UNC 

ON 14.02 B.C. 

Bevel Gear Operator Range and Specifications 

Gear Maximum Gear Mechanical Maximum Minimum Traditional Minimum Maximum Approx. 

Code Output Ratio Advantage Stem Dia. Stem Dia. Mount. Patt. Mounting Mounting Wt. w/o 

Torque w/Stem w/o Stem (as shown) Pattern Pattern Handwheel 

Protector Protector 

(Pg. #) (ft. lb.) (+/-10%) (in.) (in.) (in.) (in.) (in.) (lb.) 

BG107 1000 2.92:1 2.63 Ø 2.63 Ø 2.63 (4) 1 /2-13UNC 4.63 8.25 42 

(Pg. 10) on 7.63 B.C. 

on Centerline 

BG207 2000 4.07:1 3.66 Ø 3.950 Ø 4.125 (8) 1 /2-13UNC 7.62 10.25 75 

(Pg. 11) on 7.63 B.C. 

on Centerline 

BG307 4000 6:1 5.40 Ø 3.95 Ø 4.3 (8) 1 /2-13UNC 7.63 14.25 174 

(Pg. 12) on 7.63 B.C. 

on Centerline 

3 

(8)1-8 UNC 

on 14.00 B.C. 

Straddle 

Centerline 

Handwheel Diameters and Extensions (in.) (Extension measured from stem centerline to outer rim of wheel) 

Gear Dia. Ext. Dia. Ext. Dia. Ext. Gear Dia. Dia. Dia. 

WG008 18 9.8 24 13.3 30 14.3 BG107 18 24 30 

WG108 18 11.5 24 14.9 30 15.9 BG207 18 24 30 

WG208 18 13.6 24 17.1 30 18.1 BG307 18 24 30 

WG308 18 17.4 24 20.8 30 21.9 

WG408 18 21.2 24 24.6 30 25.7

Standard Features of the Zy-Gear Worm Gear Driven Gear Operator 

Engineered for performance, Zy-Gear worm gear operators 

incorporates precision design and rugged dependability. 

Zy-Gear worm gear driven gear operators are designed 

High strength cast iron enclosure 

Four Pre-tapped holes for limit 

switch mounting bracket 

Locking device included 

All Zy-Gear gear 

operators can easily 

be converted for 

motorized applications 

Standard Features 

• Permanently sealed and lubricated bearings. 

• Totally enclosed for buried service, seawater submersion, 

high temperature, low temperature, numerous 

chemical plant conditions and full weather resistance. 

• Strong cast iron enclosure ensures high torque capability. 

• External mechanical stops allow ± 5 degrees travel 

and precision setting of the valves closure. 

• Worm gear dual position mounting capability for 

reversal of rotation direction. 

• Comprehensive product line for torque capability. 

• Tamper proof stop and portion adjustment design. 

4 

for valves requiring 90 degree rotation. Zy-Gears are ready 

to ship from eight computer-linked regional warehouses. 

Feel and sight indicators 

Precision spur module 

Grease fitting 

Highly efficient worm module 

High strength carbon steel handwheel included 

• Machine-generated self-lock gearing assures 

minimum backlash and smooth operation. 

• Sturdy materials, proven design and quality 

manufacturing ensure trouble-free life. 

• Thrust bearings provide quality operation. 

• Industry interchangeable pre-drilled mounting pattern 

per MSS SP-101 or ISO 5211. 

• 2” square operating nut allows for removal of 

handwheel and operation by a reach rod. 

• Easily adaptable to motorized services. 

• Passed proof test at 2.5 times maximum output torque.

Zy-Gear WG008 Worm Gear Operator 

Parts And Materials 

Item Part Name Material 

1 Cover Carbon Steel 

2 O-Ring Nitrile 

3 Lock Screw Carbon Steel 

4 Stop Screw Carbon Steel 

6 Hex Bolt Carbon Steel 

7 End Cap Carbon Steel 

8 Bearing PTFE and Carbon Steel 

9 Bushing Carbon Steel 

10 Worm AISI 4135 

11 Grease Fitting Brass 

12 Pin Carbon Steel 

13 Input Shaft AISI 4135 


15 Lock Bracket Carbon Steel 

17 Key Carbon Steel 

18 Lock Plate Carbon Steel 

20 Square Nut Carbon Steel 

21 Handwheel Carbon Steel 



24 Indicator Plate Cast Iron 

26 Cover Cast Iron 

27 Gasket Rubber 

28 Worm Gear Ductile Iron 

29 Housing Cast Iron 

Ø F 

A 

A-A A-A 

Dimensional Data (in.) 

G 

B 

Ø C 

Tapped Holes • 4 x 1/4" UNC 

Bolt Circle • 4.02" 

D 

Handwheel 

Extension 

5 

E 

Ø L 

Ø H 

SECTION A-A 

Model Wt. (lb.)* A B C D E F G H I J K L 

18 9.8 

WG008 31 6.40 4.50 24 13.3 4.00 8.00 3.10 2.77 2.16 4.30 .26 .63 

30 14.3 

*Approximate weight without handwheel. 

A-A 

26 

27 

28 

29 

1 2 3 4 6 7 8 9 

10 

24 

23 

22 

SECTION A-A 

11 

K 

12 

13 

14 

15 

17 

18 

20 

21 

A-A 

I 

J




Ø F 








9 Thrust Bearing Commercial 



















A 

A-A 


G 

B 

Ø C 

A-A 

6 

1 

A-A 

26 

27 

28 

29 



2 3 4 6 7 8 

D 

Handwheel 

Extension 

24 

23 

SECTION A-A 

22 

SECTION A-A 


18 11.5 

WG108 44 6.90 4.90 24 14.9 4.00 10.00 3.55 3.45 2.15 4.20 0.14 .80 

30 15.9 


E 

Ø L 

Ø H 

11 

9 

10 

12 

31 

13 

14 

15 

17 

18 

20 21 

A-A 

K 

I 

J



Ø F 



























A 

A-A 


G 

B 

Ø C 

A-A 

A-A 

1 2 3 4 6 7 8 

27 

28 

29 

26 



D 

Handwheel 

Extension 

7 

24 

23 

SECTION A-A 

SECTION A-A 


18 13.6 

WG208 88 9.90 6.70 24 17.1 4.00 11.20 4.96 4.72 2.13 4.33 0.20 1.5 

30 15.9 


E 

Ø L 

Ø H 

22 

9 

10 

12 

13 

14 

15 

17 

18 

20 

21 

11 

A-A 

K 

I 

J




















23 Lip Seal Nitrile 







32 Housing (Spur) Cast Iron 

33 Cover (Spur) Cast Iron 

33A Gasket Rubber 

37 Bearing Dubase Alloy 



40 Spur Gear Carbon Steel 

D 

Handwheel 

Extension 

AA 

A-A 

Ø C 

B 

G 

A-A 

A 

F 

E 

B-B 

B-B 



6 

8 

9 

A-A A-A 

11 

2 

10 

31 

15 

18 

7 

23 22 

26 

27 

28 

29 

40 

32 

33A 

SECTION A-A SECTION B-B 

SECTION A-A 


Model Wt.(lb.)* A AA B C D E F G H I J JJ K L 

18 17.4 

WG308 201 12.00 6.73 8.21 24 20.8 4.00 12.30 5.43 5.32 3.03 6.43 7.90 0.47 2.25 

30 21.9 


8 

JJ 

I 

Ø L 

Ø H 

33 

21 

37 

24 

K 

38 

39 

20 

J 

1 

3 

4 

17




















23 Lip Seal Nitrile 





29 Housing Ductile Iron 

32 Housing (Spur) Cast Iron 

33 Cover (Spur) Cast Iron 

33A Gasket Rubber 

37 Bearing Dubase Alloy 




41 Dowel Pin Carbon Steel 

42 Spur Shaft Carbon Steel 


44 Bearing Commercial 

J 

Ø L 

K Ø H 


AA 

Section A-A 

I 

JJ 



9 

1 

A-A 

29 26 27 

2 3 4 6 7 8 

A 

28 

A-A 

24 

G 

23 

30 

18 

B-B 

B-B 

B 

Ø C 

A-A 

A-A 

22 41 43 44 38 

42 40 

SECTION A-A SECTION B-B 

9 

10 

11 

34 

32 

33A 

33 

15 

21 

AA 

39 20 

D 

Handwheel 

Extension 

Model Wt.(lb.)* A AA B C D E F G H I J JJ K L 

18 21.2 

WG408 443 18.59 9.30 12.40 24 24.6 4.00 NA 8.38 7.87 3.45 7.22 10.83 0.30 2.75 

30 21.9 


E 

17 

37

Standard Features of the Zy-Gear Bevel Gear Driven Gear Operator 

Zy-gear bevel gear operators actuate your multi-turn 

valves. Zy-gear bevel gears are constructed with 

all the materials, design, technology and engineering 

you expect to find in a quality gear. 

All Zy-Gear gear 

operators can easily 

be converted for 

motorized applications 

High strength carbon steel handwheel included 

Standard Features 

• O-ring sealed and lubricated for life. 

• Totally enclosed for buried service, seawater 

submersion, high temperature, low temperature, 

numerous chemical plant conditions and full 

weather resistance. 

• High strength cast iron enclosure ensures high 

torque capability. 

• Comprehensive product line for torque capability. 

• Machine-generated gearing assures minimum 

backlash and smooth operation. 

10 

They are ready to ship from eight computer-linked 

regional warehouses. 

Standard NPT stem protector thread 

• Sturdy materials, proven design and quality 

manufacturing ensure trouble-free life. 

• Industry interchangeable pre-drilled mounting 

pattern per MSS SP-102 is available upon request. 

• Adaptable to motorized services. 

High strength cast iron enclosure 

• Bevel pinion and bevel gear supported by 

anti-friction ball bearings. 

• Stem protector is available in standard NPT 

pipe sizes.

Zy-Gear BG107 Bevel Gear Operator 



A-A 


2 Washer Carbon Steel 



5 Snap Ring Spring Steel 


7 Hex Nut Carbon Steel 


9 Cap Carbon Steel 


11 Ball Bearing Commercial 

12 Set Screw Carbon Steel 

13 Pinion AISI 4135 




17 Drive Sleeve Ductile Iron 

18 Cap Screw Carbon Steel 

19 Bevel Gear AISI 4135 

20 Balls Hardened Steel 




24 Base Carbon Steel 



I 

J 

11 

1 2 

A-A 

3 5 6 7 

4 

23 

10 

8 9 

24 

11 12 14 

25 

26 

13 15 

SECTION A-A 


Model Wt. (lb.)* A B C D (NPT) E F G H I J K 

BG107 42 8.90 10.80 18.00 3.00 4.76 0.51 2.76 3.50 1.38 2.25 4.08 


K 

Tapped Holes • 4 x 1/2"-13 UNC 

Bolt Circle • 7.63" On Centerline 

B 

A-A 

Ø A 

Ø C 

Section A-A 

Driving Lugs 

Ø D 

Ø G 

Ø H 

45˚ 

TYPICAL 

16 

17 

18 

19 

20 

21 

22 

A-A 

E 

F





























27 Snap Ring Steel 

A-A 

I 

J 

K 



12 

3 

1 2 

A-A 

4 7 

10 

5 6 9 

23 

8 

24 

12 14 13 

25 27 

26 

15 

SECTION A-A 



BG207 75 11.92 10.79 24.00 4.00 5.47 0.77 4.35 5.24 1.38 2.25 3.04 


B 

A-A 

Ø A 

Ø C 

Section A-A 

Driving Lugs 

Ø D 

Ø G 

Ø H 

45˚ 

TYPICAL 

16 

17 

18 

19 

20 

22 

21 

A-A 

E 

F





























27 Snap Ring Steel 


A-A 

I 

J 

K 

13 

3 5 6 8 

2 

1 

A-A 

4 7 9 

10 

11 

23 

28 

13 14 15 

24 25 

27 

SECTION A-A 



BG307 174 16.35 10.79 24.00 4.00 6.91 0.87 4.33 5.38 1.38 2.25 4.66 


B 

Tapped Holes • 8 x 1"-8 UNC 

Bolt Circle • 14.00" Straddle Centerline 

A-A 

Ø A 



Ø C 

SECTION A-A 

Driving Lugs 

Ø D 

Ø G 

Ø H 

45˚ 

TYPICAL 

16 

17 

18 

19 

20 

22 

21 

26 

A-A 

E 

F

Specifying Zy-Gear Worm Gear 

When ordering worm gears pre-bored and keyed from 

the factory, the following information must be provided. 

1. Maximum torque required 

2. Gear type: WG008, 108, 208, 308 or 408 

3. Bore and keyway size with tolerances. Specify key 

shape, square or rectangle in width x width. 

4. Location of keyway, A, B, C or D (see diagram) 

5. Mounting pattern in ISO 5211 or MSS SP101 F 

numbers or special patterns, metric or inch 

thread holes 

6. Handwheel sizes, 18", 24" or 30" diameter 

Zy-Gear Technical Formulas 

14 

C 

D 

B 

A 

TOP VIEW 

Close Clockwise 

Basic Formulas Conversion Factor for Force 

Mechanical Advantage (MA) = Output torque/Input torque 

Multiply By To Obtain 

Overall mechanical efficiency = MA of spur gear x MA of worm gear 

Pound - Force 4.44822 Newton (N) 

Input torque =Output torque/MA 

Newton (N) 0.22481 Pound- Force 

Output torque = Input torque x MA 

Newton (N) 0.10197 Kilogram - Force 

Efficiency %= [Output torque x 100]/[Input torque x Gear ratio] 

Overall Efficiency % = [Spur efficiency x worm efficiency] /100 

Ratio = Number of turns of input/Number of turns of output 

Kilogram - Force 9.8066 Newton (N) 

Overall ratio = Spur gear ratio x Worm gear ratio 

Conversion Factor for Torque 

Number of turns to close = Gear ratio/4 

Multiply By To Obtain 

Closing time (min.) = Number of turn to close/Input speed (RPM) 

Closing time (sec.) = Number of turns to close x 60/Input speed (RPM) 

Pound - Foot 

Newton - meter (Nm) 

1.3558 

0.73756 

Newton - meter (Nm) 

Pound - Foot 

Input speed (RPM) = Number of turns to close/Closing time (min.) 

Newton - meter (Nm) 0.10197 Kilogram - meter 

Number of turns to close = Input speed (RPM) x Closing time (min.) 

Torque = Force x Radius 

Input torque = [Handwheel rim effort x Handwheel diameter] /2 

Handwheel rim effort = [Input torque x 2] /Handwheel diameter 

Handwheel diameter = [Input torque x 2]/Handwheel rim effort 

Kilogram - meter 9.8066 Newton - meter (Nm) 

NOTE: Units must be consistent within the formula.

Zy-Gear Installation & Maintenance 

Worm Gear Operator Installation, Adjustment and Maintenance 

Installation 

Ensure that gear operator and the valve are both in corre- wrench is not engaged with the stop screw. Turn the lock 

sponding positions, fully open or fully closed. If the gear screw clockwise until it contacts the stop screw. Re-install 

position does not match the valve position, rotate the hand- the cover bolt with the o-ring. Turn handwheel to the true 

wheel until the gear and valve are in the same position. closed position; repeat the above steps on the closed side 

Check to ensure the keyway on valve stem and worm gear stop screw adjustment. The true closed position of the valve 

are aligned. Install mounting studs into bottom of the worm may require setting during the time of the seat leak test. 

gear. Align the gear bore with the valve stem and lower the 

Adjustment Notes 

gear to the mounting flange or plate. Fasten the nuts. 

*Open side of the stop screw is located at the far side from 

the handwheel on WG 008, 108, 208 and 408. It is located at 

the near side from the handwheel on WG 308. In general, if 

the handwheel is at the right side of the gear at top view, the 

open stop screw is at the far side. If the handwheel is at the 

left side of the gear at top view, the open stop screw is at the 

near side from the handwheel. 

Adjustment 

Refer to gear diagram of each model from page 5 to 9 for 

gear parts. Locate the open side* of the stop screw cover 

bolt. Remove the cover bolt and o-ring assembly, item 1 and 

2, and loosen the lock screw, item 3, and the stop screw, item 

4, with an Allen wrench**. Lock screw has a through hex 

hole with the same size as the socket hole on the stop screw. 

Allen wrench may go through the socket hole of the lock 

screw and reach the hole of stop screw. Turn the handwheel 

to get the true open position of the ball, disc or plug, etc. 

Turn the stop screw clockwise until it comes into contact 

with the worm gear. Back up the wrench and make sure the 

Bevel Gear Operator Installation & Maintenance 

Installation 

Inspect the gear to verify it’s the right gear specified on the 

name plate. Ensure that the valve torque is within the gear 

rating. Support valve in the upright position (Fig. 1). 

Remove handwheel from the valve (Fig. 2). Place adapter 

plate* on top of the valve yoke (Fig. 3). Align bolt holes of 

the adapter plate with respect to the valve bore making 

sure that gear input shaft will be in desired position after 

mounting. Align center of the adapter plate with stem center 

line. Tack-weld plate to valve yoke. Check to verify the 

alignment, then complete with a full circumferential weld. 

Set the driver* on the yoke sleeve where the handwheel 

was set (Fig. 4). Set the gear operator on top of the adapter 

plate (Fig. 5). Rotate the gear 

Set Screw 

operator to engage the 

Handwheel Nut 

driver and align the 

input shaft 

Handwheel Nut 

Handwheel 

Yoke 

Handwheel 

15 

**Allen wrench sizes needed: WG 008 and WG 108: M12, 

WG 208: M16, WG 308, WG 408: M24 

Maintenance 

Zy-Gear gears are permanently lubricated for safe operation for 

the life of the gears and do not require periodic maintenance. 

and the mounting holes. Install and tighten the mounting 

bolts. Install the stem protector as required. Cycle the 

valve to ensure proper operation of the valve. For NRS 

valves, please contact your Zy-Gear salesperson. 

Installation Note 

*Both Adapter plate and Driver are designed to fit a specific 

valve. A top work dimension is needed for choosing 

the proper adapter plate. Consult salesperson if assistance 

is needed. 

Maintenance 

Zy-Gear bevel gears are equipped with grease fittings to 

allow for grease injection to minimize wear. 

Typical Gate Valve Installation Illustrated below. 

Adapter Plate 

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 

Weld 

Driver 

Gear 

Stem Protector 

Bolt


Contact your local Zy-Tech representative for more 

information about Zy-Gear Gear Operators or visit 

our website at www.zy-tech.com and view Zy-Tech’s 

entire collection of flow control products. 

Your Local Representative 

Warranty 

The warranty described below applies only to new or unused goods, or goods reconditioned by ZY-TECH GLOBAL 

INDUSTRIES (Seller). The Seller specifically disclaims any warranty for used goods or goods sold “as is”. For a period 

of one (1) year after date of purchase of any of the goods described herein, Seller warrants such goods shall remain 

free from failure due to defects in workmanship and materials incorporated therein by or for Seller provided such 

failure shall not have been caused or contributed to, by improper usage, service or application, improper installation 

or maintenance, repairs, alterations, or modifications effected by or for the user, misuse, negligence or accident. 

In the event of failure for which Seller has assumed warranty obligations hereunder, and provided written notification 

of such failure shall be immediately given to Seller, it agrees to repair, or at its option, to replace the goods sold 

at its sold expense. 

Apart from the warranty and undertaking above set forth, Seller assumes no obligation or liability for losses, expense or damages, 

direct or consequential, suffered or incurred as a result of any failure of, or defect in, the goods described herein, including 

but not limited to, such costs, expenses or damages as may result from the necessity to remove, replace, restore or 

transport the goods from any location or service in which they may be used, regardless of the cause of such failure 

or defect. 

This warranty extends only to the original Purchaser of the goods and is the only warranty made by Seller in connection therewith. 

There are not other warranties, express or implied, of any kind given with respect to the goods, their merchantability, fitness 

for any particular purpose or usage, or otherwise, nor is any person authorized to extend on behalf of Seller any form of 

warranty other than that above set forth. 

The goods described herein are not sold or distributed by Seller for personal, family or household purposes, nor are 

they normally suited for use as such. 

10600 Corporate Drive, Stafford, Texas 77477 

(281) 565-1010 • (800) 231-3530 • Fax (281) 565-3171 

Sales@zy-tech.com 

©2004 Zy-Tech Global Industries, Inc. • Zy-Gear is a product of Zy-tech Global Industries, Inc. • ZGI-ZG-BWGOP-204

Worm & Bevel Gear Operators - Pro-Tech Valves

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