Setting And Testing; General Information; Test Equipment; Test Media - Baker Hughes Consolidated 19000 Series Instruction Manual

XVI. Setting and Testing
Decontaminate or clean,
if necessary, before pre-
testing or disassembly.
Safety and environmental
precautions must be taken
for the decontamination or
cleaning method used
Do not stand or place
hand in front of valve
dischargeflangeifvalve
is under pressure.
E. Set Pressure Compensation
ColdDifferentialTestPressureforTemperature
Compensation
During production testing, the SRV is often tested at
temperatures that are different from the temperatures
the SRV will be exposed to in service. Increasing the
temperature from ambient temperature causes the set
pressure to decrease. The decrease in set pressure is
due to thermal expansion of the seating area and spring
relaxation. Therefore, it is important to compensate for
the difference between production test temperature and
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A. General Information
Before putting the reconditioned valve in service, it must be set to open at the required
set pressure as shown on the nameplate. Although the valve can be set on the service
installation, it is more convenient to set the valve and check seat tightness on a test
stand. Any spring replacement shall be in accordance with current guidelines.
B. Test Equipment
The test stand used for testing SRVs normally consists of a pressure source supply line
with a throttle valve and receiver that have the following features:
1. Outlet for attaching the valve to be tested;
2. Pressure gauge with a shut-off valve;
3. Drain line with a shut-off valve; and
4. Adequate receiver volume for the valve to be tested and to achieve proper
operation.
C. Test Media
For best results, valves shall be tested by type as follows:
1. Steam valves are tested on saturated steam;
2. Air or gas valves are tested on air or gas at ambient temperature; and
3. Liquid valves are tested on water at ambient temperature.
D. Setting the Valve
Set the valve to open at the set pressure as shown on the nameplate. If a cold differential
test pressure is indicated on the nameplate, set the valve to open at that pressure
on the test stand. (The cold differential test pressure is the set pressure corrected to
compensate for backpressure and/or operating temperature.) A new cold differential test
pressure may need to be determined if changes are to be made to the set pressure or
backpressure or if the service temperature changes.
Note: This design will allow the set pressure to remain constant under
superimposed variable back pressure conditions. If changes are to be made
to the set pressure or back pressure or the service temperature changes, a
newcolddifferentialtestpressuremayneedtobedetermined.
service temperature. The service temperature is the
normal operating temperature of the SRV. If the operating
temperature is unavailable, do not correct the SRV set
pressure.
Table 11 lists the set pressure multipliers to be used when
computing the cold differential test pressure (CDTP)
pressure for valves being set on an air or water test stand at
ambient temperatures.
Valves to be used in saturated steam service are tested on
saturated steam. Therefore, no CDTP is required. However,
valves in superheated steam service are tested on saturated
steam and require a CDTP.
Consolidated 19000 Series Safety Relief Valve Instruction Manual
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