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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
The integrated valve test system (referred to below as "VPS") is used to test the fuel valves for leaks. The operating pressure in the gas valve train is used for the test. The fuel valve test is performed in two phases. Test phase one tests the fuel valve 1 (intake side) and test phase two tests the fuel valve 2 (burner side).
The two pressure monitors "VPS test pressure MAX" and "VPS test pressure MIN" are used in both test phases for pressure monitoring in the test segment. The switch point (normally closed contact) of the pressure monitor "VPS test pressure MAX" is set to the maximum test pressure. The switch point (normally open contact) of the pressure monitor "VPS test pressure MIN" is set to the minimum test pressure.
Design of a gas train with valve test system, variant with one pressure monitor
The "MIN gas pressure monitor" is used in both test phases for pressure monitoring in the test segment. The switch point (normally open contact) of the pressure monitor is set to the required minimum operating pressure.
Design of a gas train with valve test system, variant with two pressure monitors
Fuel valve 1 (input side)
Fuel valve 2 (burner side)
Relief valve (if present)
Gas pressure monitor MIN
Pressure monitor VPS test pressure MIN
Pressure monitor VPS test pressure MAX
The following table shows the possible FSC input configurations (pressure monitor combinations) and the resulting valve test and gas pressure MIN monitoring methods.
If no "gas pressure monitor MIN" input signal is available in an FSC input configuration for a gaseous fuel, then the gas pressure monitor MIN must be integrated into the fuel-specific safety interlock circuit (gas).
The valve test for gaseous fuels is only performed if the safety interlock circuit for fuel 1 / fuel 2 is closed prior to or during the valve test.
When the valve test is requested, the pressure in the control segment is relieved for set relief time. The test segment is then monitored for pressure rise for the configured test time for fuel valve 1.
A safety shut-off is triggered if the pressure increases beyond the limit within the first test phase.
After the end of the first test phase, the pressure in the test segment is charged for the configured charge time. Then the test segment is monitored for a pressure drop for the configured test time for fuel valve 2.
Wenn innerhalb der zweiten Prüfphase der Druck unzulässig abfällt, wird eine Sicherheitsabschaltung ausgelöst.
The valve test has been completed successfully at the end of the second test phase.
See also
Flow chart: Valve Test, Variant with One Pressure Monitor
Flow chart: Valve Test, Variant with Two Pressure Monitors
DOC-719332673
