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Anderson Greenwood SerieS 93 PoSitive PreSSure PoSrv
InstallatIon and MaIntenance InstructIons
FiGure 7
6 leAk testinG AsseMbly
6.1 General
the complete valve assembly should be leak
tested for internal and external leaks using a
pressure equal to 30% and 90% of set.
6.2 internal leak test
Cover valve outlet with wet piece of paper and
observe paper for movement. Any outward
movement indicates a leak. if leakage is
detected, remove paper and spray leak test
solution around nozzle/seat to locate leak.
Leakage my be caused by damaged seat
sealing surface or improper squeeze of o-ring
or sponge seat.
6.3 external leak test
Following the internal leak test, check for
external leakage by applying leak test solution
to all joints and seals. tighten bolts or fittings
as required.
Field test valve "B"
Flexible hose
test gage
Block valve "A"
vent valve "C"
Nitrogen
bottle
7 pilot set pressure field test
procedure
7.1 General
the pilot set pressure can be checked in the
field by applying an external test pressure to
the pilot through the field test hand valve as
shown in Figure 7.
note: if the process pressure at the time of test
is less than approximately 30% of the pilot set
pressure, the main valve will not open. if the
process pressure is greater than 30% and the
main valve must remain closed,
temporarily replace the pilot exhaust vent with
an orifice plug having an orifice diameter of
.040"/.060". this orifice must be removed on
completion of field testing as it prevents the
main valve from opening.
7.2 procedure
A. Connect test gas bottle as shown in
Figure 7.
B. Close vent valve "C".
C. open field test valve "B". test gauge will
read process pressure.
D. open block valve "A" SLoWLY to increase
pressure until pilot "pops". the set pressure
will be the pressure indicated on the test
gauge at the time of pop.
e. to remove test set up, close valves "A" and
"B", open valve "C".
9
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