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Valve test system
Type
F [1 - 3]: VPS: Load valve
F [1 - 3]: VPS: Load time
F [1 - 3]: VPS: Relief valve
F [1 - 3]: VPS: Relief time
VPS: Calculating the testing times
F [1 - 3]: VPS: Fuel valve 1: Proof time
F [1 - 3]: VPS: Fuel valve 2: Proof time
F [1 - 3]: VPS: Valid time
F [1 - 3]: VPS: Fuel valve 2: Delayed close
Set the test times in consideration of the permissible leakage rate.
You can use the formulas below to calculate the leakage rates or test times. The formulas are based on the dependency of the programmed test time or leakage rate on the total volume and the pressure loss in the test segment.
Fuel valve 1 leakage rate
Fuel valve 2 leakage rate
Fuel valve 1 test time
Fuel valve 2 test time
Leakage rate for fuel valve 1, in dm³/h
Leakage rate for fuel valve 2, in dm³/h
Test time for fuel valve 1, in s
Test time for fuel valve 2, in s
Pressure before start of test in test segment, in mbar
Pressure at end of test in test segment, in mbar
Physical pressure of the atmosphere, 1013 mbar,
Total volume of test segment and of valves under test, in dm3
The following example shows how to calculate the detectable leakage rates for the variant with one pressure monitor.
Max. fuel gas consumption 664 m3/h
Operating pressure gas: 200 mbar
Pressure monitor switch point: 140 mbar (70 % of the gas operating pressure)
Pressure monitor switching hysteresis: ±7.5 mbar
Total volume: 5.5 dm3
Maximum leakage rate:
Detectable leakage rate for main gas valve 1 at a test time of 30 s:
Detectable leakage rate for main gas valve 2 at a test time of 30 s:
This example produces the following pressure characteristic curve during the valve test in the variant with one pressure monitor:
Pressure characteristic curve of a valve test with one pressure monitor
Fault test phase 1: Pressure greater than MIN
Fault test phase 2: Pressure less than MIN
Pressure before fuel valve 1 test start
Gas pressure monitor switching pressure MIN
Switching pressure (plus switching hysteresis) fault test phase 1
Pressure before fuel valve 2 test start
Switching pressure (minus switching hysteresis) fault test phase 2
Pressure relief in the test segment (5 s)
Test time for fuel valve 1 (30 s)
Pressure build-up in the test segment (5 s)
Test time for fuel valve 2 (30 s)
The following example shows how to calculate the detectable leakage rates in the variant with two pressure monitors.
Operating pressure gas: 3000 mbar
Pressure monitor switching pressure MAX: 150 mbar
Pressure monitor switching pressure MIN: 2850 mbar
This example produces the following pressure characteristic curve during the valve test in the variant with two pressure monitors:
Pressure characteristic curve of a valve test with two pressure monitors
Fault test phase 1: Pressure greater than MAX
Switching pressure, pressure monitor VPS test pressure MAX
Switching pressure, pressure monitor VPS test pressure MIN
DOC-719835090
