Emerson ANDERSON GREENWOOD MARVAC 121 Series User manual

ANDERSON GREENWOOD MARVAC FIGURE 121 PRESSURE AND VACUUM RELIEF VALVE
INSTALLATION AND MAINTENANCE INSTRUCTIONS
SAFETY PRECAUTIONS
Read and understand this instruction manual
before installing, operating or performing
maintenance on Figure 121 pressure and
vacuum relief valves. Follow all precautions
and warnings noted herein when installing,
operating or performing maintenance on this
equipment.
NOTE
This manual is issued for guidance only and does not
affect our standard terms and conditions and our
product limited warranty, all of which are available on
request.
Read Anderson Greenwood Marvac general instructions before continuing
1 INSTALLATION
Figure 121 pressure and vacuum relief valves
must be mated with the appropriate flange.
1. These valves must be gasketed and bolted
to a flat machined horizontal flange. Bolts
must be tightened uniformly to ensure a
good seal.
2. This valve does not contain any internal
packing. Therefore, internal checks should
not be necessary.
3. It is recommended that carbon steel valves
be given a coat of paint immediately after
installation is complete. Apply paint to
external surfaces only.
2 MAINTENANCE
(during atmospheric venting period)
WARNING
The relief valve must be isolated from tank
pressure before servicing. All gas must be
blocked and pressure vented safely. Wear
appropriate gloves and/or breathing apparatus if
hazardous vapors are present.
© 2017 Emerson. All Rights Reserved.Emerson.com/FinalControl VCIOM-01934-EN 15/12
Refer to Figure 1
1. Remove weather hood (item 3) and vacuum
cover (item 7), inspect O-ring in vacuum
cover for damage and replace if necessary.
2. Remove pallet assembly to inspect pallet
seating for wear and replace if necessary.
3. To replace damaged/worn items from pallet
assembly (see recommended spares):
a. remove nut from pallet stem, remove
support disc, diaphragm and backing disc
b. clean pallet surface and threads
c. replace with new parts
d. reassemble in reverse order
4. Inspect valve seat (item 2) for wear and
regrind or replace where necessary.
5. Clean seating surface thoroughly with
suitable solvent and apply a thin smear of
light spindle oil.
6. Generally clean the inside of the valve,
remove all foreign matter and repaint
exterior where possible to prevent
corrosion.
7. Replace pressure pallet on pressure seat
and vacuum pallet (with lead disc if fitted).
8. Replace weather hood, secure with hand
nuts.
9. Replace vacuum cover and replace sealing
washers if necessary, secure with screws.
NOTE
The efficiency of the valve depends on maintaining
good seating surfaces. Therefore, maintenance
periods should be adjusted to suit service conditions.

2
ANDERSON GREENWOOD MARVAC FIGURE 121 PRESSURE AND VACUUM RELIEF VALVE
INSTALLATION AND MAINTENANCE INSTRUCTIONS
3 RECOMMENDED SPARES
1. Item 10 Nitrile o-ring
2. Item 9 Sealing washers
3. Item 14 Spacer disc (non-asbestos fiber)
4. Item 15 Diaphragm backing disc
(non-asbestos fiber)
5. Item 16 Diaphragm (PTFE)
PARTS LIST
Item Description Alum spec. C.steel SS spec
1Valve body Aluminum W.C.B. 316 SS
2Removable seat Aluminum 316 SS 316 SS
3Weather hood Aluminum C.Steel 316 SS
4Handle nuts Phenolic Phenolic Phenolic
5Screen ring Aluminum C.Steel 316 SS
6Screen Galv St Galv St 18/8 SS
7Cover Aluminum W.C.B. 316 SS
8Cover screws ZP Steel ZP Steel 18/8 SS
9Sealing washers G Fiber G Fiber G Fiber
10 O-ring seal Nitrile Nitrile Nitrile
11 Pallet 316 SS 316 SS 316 SS
12 Pallet stem 316 SS 316 SS 316 SS
13 Pallet guide posts 316 SS 316 SS 316 SS
14 Spacer disc Non-asbestos Non-asbestos Non-asbestos
15 Diaphragm back.disc Non-asbestos Non-asbestos Non-asbestos
16 Diaphragm PTFE PTFE PTFE
17 Diaphragm supp.disc 316 SS 316 SS 316 SS
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Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
Anderson Greenwood is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation
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The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be
construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed by
our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without
notice.
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FIGURE 1