Valve Proving - Siemens LMV37.4 Series Basic Documentation

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Building Technologies

7.5.2 Valve proving

Valve proving is only active when firing on gas. Valve proving designed to detect leaking
gas valves and, if necessary, to prevent the valves from opening or ignition from being
switched on. Lockout is initiated, if required.
When performing valve proving, the gas valve on the burner side is opened first to bring
the test space to atmospheric pressure. After closing the valve, the pressure in the test
space must not exceed a certain level. Then, the gas valve on the mains side is opened
to fill the gas pipe. After closing, the gas pressure must not fall below a certain level.
Valve proving can be parameterized to take place on startup, shutdown, or on both.
The type of valve proving can be selected via parameter 236 / 237.
Recommendation:
Perform valve proving on shutdown.
No. Parameter
Gas: Input pressure switch-min
1 = pressure switch-min before fuel valve V1 (default setting)
236 2 = valve proving (between fuel valve V1 and fuel valve V2) via pressure
switch-min
3 = pressure switch-min after fuel valve V2
Gas: Input pressure switch-max / POC
1 = pressure switch-max
237
2 = POC
3 = pressure switch valve proving
4 = additional speed-dependent air pressure switch
Gas: Execution-valve proving
0 = no valve proving
241 1 = valve proving on startup
2 = valve proving on shutdown
3 = valve proving on startup and shutdown
Gas: Valve proving - test space evacuating
242
Gas: Valve proving - test time atmospheric pressure
243
Gas: Valve proving - test space filling
244
245 Gas: Valve proving - test time gas pressure
Caution!
If valve proving is parameterized to take place «on startup and shutdown», the
gas valves must run through additional switching cycles. As a result, strain on
the gas valves (wear) increases.
Caution!
The OEM must set the evacuation, filling and test times for atmospheric or
mains pressure on every plant in compliance with the requirements of EN 1643.
Basic documentation LMV37.4...
7 Basic unit LMV37.4
CC1P7546en
17.12.2018