5
2”
8.3
4.8
3”
16.8
9.7
4”
22.1
12.8
6”
43.4
25.1
8”
72.7
42.0
10”
120.1
69.4
12”
179.9
104.0
VAREC
7100B SERIES PRESSURE RELIEF VALVE
INSTRUCTION, OPERATION AND MAINTENANCE MANUAL
3. To replace seat ring, proceed as follows:
a) Remove weatherhood, pallet assembly,
screen, spacer ring, guide posts and seat
ring retainer.
b) Remove seat ring and O-Ring from valve
body. Clean body mating surface and
O-Ring groove.
c) Install new O-Ring into groove, insure
that the O-Ring stays properly in groove
while installing seat ring.
d) Install new seat ring carefully to avoid
distortion. Reassemble guide posts to
secure seat. Ensure that seat is flush
and level with valve body.
e) Place pallet assembly on valve body seat.
Ensure pallet moves freely within guide
posts and rests flat on seat ring.
f) Reinstall screen and weatherhood.
4. Seat ring repair:
a) Seat may be ground or ground and
lapped (in place) to improve seal. Use a
lapping plate and medium valve grinding
compound, applying light pressure.
b) Finish lapping with a fine compound.
Avoid scoring or removing excessive
amounts of material.
c) Clean all compound from valve parts.
d) Hand buff seat with a medium grade
`Scotch-Brite’ (#7447) pad and light oil.
CAUTION
Whenever the weatherhood is removed and
reinstalled, the end of the pallet stem must
engage the guide tube in the weatherhood for
proper pallet seating and valve operation.
CALIBRATION (ADJUSTMENT)
It is important to verify setting by calculating
the total necessary weight using Table 3. Check
this value against the actual weight of the pallet
assembly (including loading weights). Adjust
loading weights as required.
2. To replace pallet insert, proceed as follows:
a) Remove weatherhood and then the
pallet assembly.
b) Remove nut from base of pallet stem.
Remove retainer plate and insert.
Clean all surfaces and threads. Install
new insert, handling carefully to avoid
damaging insert or pallet.
c) Reassemble pallet and place on seat of
valve body. Ensure pallet moves freely
within guide posts and rests flat on
seat ring.
d) Reinstall weatherhood.
CAUTION
The end of the pallet stem must engage the stem
guide in the weatherhood for proper seating and
valve operation.
CAUTION
Whenever the weatherhood is removed and
reinstalled, the end of the pallet stem must
engage the guide tube in the weatherhood for
proper pallet seating and valve operation.
TABLE 3 - PALLET LOADING (INCLUDES WEIGHT OF PALLET)
Valve
size
Ounces of weight required
per ounce of setting
Ounces of weight required
per inch of WC setting
Weight tolerance: + 5%/- 5%
Setting tolerance: + 0%/- 10%
