Maintenance - Emerson VAREC Series Instruction, Operation And Maintenance Manual

VAREC SERIES 2010B/2020B/3500B PRESSURE AND VACUUM RELIEF VALVE
INSTRUCTION, OPERATION AND MAINTENANCE MANUAL
CAUTION
The end of the pallet stem must engage the
stem guide in the weatherhood or the stem guide
chamber in the cover for proper seating and valve
operation.
5. Place the valve in a level position. Reach up
through the inlet flange and carefully push
up on the pressure pallet, then lower it onto
the seat. Pallet should move up and down
freely and rest flat on the seat ring.
6. Check the vacuum pallet by using a non-
sparking tool which will pass through the
center of the mesh screen. Push up on the
vacuum pallet, then lower it onto the seat.
Pallet should move freely and rest flat on
the seat ring.
7. Mount the valve on the flanged nozzle or
flame arrester using the appropriate full
faced gasket.
CAUTION
Do not mate a flat face flange to a raised face
flange.
If it necessary to mate an ANSI Class 125 F.F.
Flange with an ANSI Class 150 R.F. Flange, use
the proper spacer to convert the raised face to
a flat face.
8. Verify that the valve is level to permit proper
operation of the pallets. Install mounting
hardware, and tighten uniformly.
9. When using Model 2020B Series, install
connecting piping (if required) to outlet
flange. Use a full faced gasket and tighten
all mounting hardware uniformly.
Note: it is recommended that steel and iron
valves be given a coat of paint immediately
after installation is completed. Apply paint
to external surfaces only.

MAINTENANCE

The valve should be inspected and cleaned
at periodic intervals. The first inspection
should be made approximately 30 days after
commissioning. Subsequent inspections should
be made every 30 days. The user may adjust the
schedule for his own convenience and safety,
depending upon the product being stored.
WARNING
• Relief valve must be isolated from tank pressure
before servicing. All gas must be blocked and
pressure safely vented. If no isolation valve
is present, carefully open vacuum cover or
lift pressure pallet, allowing pressure to vent
slowly.
• Wear appropriate gloves and/or breathing
apparatus if hazardous vapors are present.
1. To inspect valve proceed as follows:
a. Remove the weatherhood and/or
cover(s).
b. Remove pallets one at a time. Identify the
pallets to ensure they are returned to the
correct valve seat.
c. Inspect pallet inserts for ripples, tears,
or nicks, as well as seating surfaces for
debris, abrasion or pitting. Pallet edges
and guide posts should be free or burrs,
corrosion or other obvious damage.
Clean all components, replacing any
showing excess wear or damage. On the
"All-Weather" versions, inspect the PTFE
coating for any damage that would affect
operation.
d. Reassemble in reverse order.
CAUTION
The end of the pallet stem must engage the stem
guide in the weatherhood and/or the stem guide
chamber in the cover(s) for proper seating and
valve operation.
CAUTION
During periods of freezing weather, extra
maintenance is required for Models
2010B/2020B/3500B. Either remove the pallets or
apply generous portions of silicone grease to the
pallets, seat rings and guide posts. When using
silicone grease, inspect valves at least weekly.
This procedure is not required for "All-Weather"
Models 2011B, 2021B or 3501B.
2. To replace pallet insert proceed as follows:
a. Remove weatherhood and/or cover(s)
and then 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 assembly
moves freely within guide posts and
rests flat on seat ring.
d. Reinstall weatherhood and/or cover(s).
CAUTION
The end of the pallet stem must engage the stem
guide in the weatherhood and/or the stem guide
chamber in the cover(s) for proper seating and
valve operation.
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