T3 PRV Catalogue b&w.cdr - Atvus Industries

PRESSURE RELIEF VALVE
FOR OIL FILLED TRANSFORMER
Type :T3
FEATURES
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Pressure Die Cast Aluminium flange and cover provides compact robust construction, free of blow holes.
Deep drawn Stainless Steel operating diaphgram.
Automatic and instantaneous venting and sealing.
Ideal for OLTC tanks and small transformer tanks.
Optional switch with indicator.
IP 67 protection for switch.
100% operation test for each instrument.
Unique spring retainer provided for flawless repeated operations.
Specially designed reverse wound springs and assembly provide uniform valve loading and improved relief rates.
Stainless Steel springs for long life.
AT-301 IN SERVICE TO THE TRANSFORMER INDUSTRY SINCE 1971

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10
6
4
8
7
5
3
1
2
CONSTRUCTION WORKING APPLICATION
The Pressure Relief Valve
consists of an integral flange (1)
with gasket (2) for mounting on
transformer tank. The Stainless
Steel diaphragm (3) is spring (4)
loaded and seals the 70 mm port
against top and side gasket (5&6).
The cover (7) retains and
compresses the spring and is held
in place by six screws (8). The
spring retainer (9) prevents the
dislocation of springs during
repeatedoperations.
The switch assembly (10) for
alarm is optional and houses one
NO and one NC contact (four
terminals). It also has a visual
indicator(11).
When pressure in the tank
rises above the safe limit, the
operating disc moves slightly
upwards from top gasket. This
exposes the transformer pressure
to agreater area corresponding to
the diameter of side gasket,
resulting in sudden increase of
force.Thediskliftsinstantaneously
and vents gases, vapour and liquid
till the pressure falls to allowable
values.
These Pressure Relief Valves are
recommended to be used on all
sizes of OLTC and transformers
ranging from 250 KVA to 5MVA.
They are much more effective,
durable, suitable for repeated
operations than the conventionally
usedexplosionvent.

MOUNTING
The Pressure Relief Valve should be preferably
mounted in the horizontal position, top side up. It may
howeverbemountedonitsside,inverticalplane.
DETAILS OF MOUNTING PAD
4NOS. M10 TAPPED HOLE
O
ON 127P.C.D. AT90 APART
INSTALLATION
Clean surface of mounting pad on tank and place the
flange with gasket. Use M12 x30 bolts with washers
for tightening. Ensure that the gasket is placed in the
grooveprovidedintheflange.
TOP VIEW
150
68
ALL DIMENSIONS ARE IN mm.
Check the operation of switch by manually lifting the
operating rod. After checking, the switch should be
manually reset by placing the roller type knob back to
itsoriginalposition.
SECTIONALFRONTVIEW
DETAILOFMOUNTINGPLATE
(NOT SUPPLIED BYUS)
HORIZONTAL &VERTICAL MOUNTING
MAINTENANCE
The Pressure Relief Valve has arugged construction
and does not require any maintenance. The operating
pressure is factory preset and cannot be changed at
site. It is strongly recommended that the compression
screws on the cover should never be removed without
useofextremecaution.Theoperationofswitchmaybe
periodicallytestedbymanually liftingtheoperatingrod
and should be reset before putting the instrument in
service.
APPLICATION
HORIZONTAL
VERTICAL
VALVE SPECIFICATIONS
1. Liquid in tank : Transformer oil
2
2. Operating Pressure : 0.42 Kg/cm (6 PSI)
2
0.49 Kg/cm (7 PSI)
2
0.56 Kg/cm (8 PSI)
2
0.70 Kg/cm (10 PSI)
3. Operating tolerance :
2
+ 0.07 Kg/cm (1.0 PSI)
4. Operating time : Instantaneous
O
5. Operating temperature : 0to 100 C(of transformer oil)
6. Portopening : 70 mm Dia
7. Valve resetting : Automatic
8. Switch : Limit Switch D.P.D.T.
9. Switch resetting : Manual
10. Environment : Indoor &Outdoor
SWITCH SPECIFICATIONS
1. Number of switch : 1Limit switch
2. Operation : Automatic
3. Contact rating : AC :240V 10 Amp
DC :240V 0.4 Amp
4. Number of contacts : 1NO +1NC
2NO +2NC (optional)
5. Weather protection : IP 67
6. Cable entry : 3/4” Conduit

SWITCH OPERATION
BEFORE VALVE OPERATION
1 2 3
4
TERMINAL NOS.
AFTER VALVE OPERATION
HOLE FOR CABLE ENTRY
(3/4" x16 TPI)
LIMIT SWITCH
1 2
3 4
WIRING DIAGRAM
ALARM
1
2
4NOS. LUGS
12WIDE127 P.C.D.
FOR MOUNTING
SUPPLY
ALARM
3
4
150ø
GASKET
(SUPPLIED BY US)
ALL DIMENSIONS ARE IN mm
SUPPLY
ToOrder,Or For Quotation, Specify :
1. Model Number
2. Operating Pressure
-T3 -With Switch (1 NO +1NC)
-T3-2 -With Switch (2 NO +2NC)
-T3W -Without Switch
2
a) 0.42 Kg/cm (6 PSI)
2
b) 0.49 Kg/cm (7 PSI)
2
c) 0.56 Kg/cm (8 PSI)
2
d) 0.70 Kg/cm (10 PSI)
e) Other than above
Due to our policy of continuous product improvement, dimensions and designs are subject to change.
INDUSTRIES
689, Block ‘O’, New Alipore, Kolkata -700 053, INDIA
Phones: (91-33) 24001101, 24009885 Fax: (91-33) 24007443, 24007043 E-mail: atvus@dataone.in