RM7800L1087; RM7840G1022,L1075; EC7840L1014 RELAY MODULES WITH VALVE PROVING
66-1162—2 26
APPENDIX A
Valve Proving Test
The Valve Proving System feature offers a systematic way of
testing the valve seat integrity to assure the valves are indeed in
the closed position when the system is off-line, in STANDBY.
WARNING
Explosion Hazard.
Can cause severe injury, death or property damage.
Leaking gas valves can result in fire or explosion. The
Valve Proving System is designed to detect such
leaks. A valve proving test time that is too short may
allow unacceptable leaks to go undetected. Use the
procedure in Appendix A to select sufficient valve test
times to detect any unacceptable leak.
The following steps are to determine the test time for the relay
module to verify the valve seats are not leaking at a rate of
greater than/equal to 0.1% of the burner capacity.
Fig. 29 shows a typical valve train. The legend identifies
information that will be used to fill out the worksheet that
appears at the end of this appendix.
1. Identify items of your system and fill in the “Information”
portion of the worksheet.
2. Go to the Lookup Tables noted (13, 14 or 15) to get the
results for your system.
IMPORTANT
The Tables show information on Honeywell Valves
only. Contact other valve manufacturers to obtain
data on their specific valves.
Fig. 28. Typical valve train layout.
3. Use appropriate Results column items to fill in the Valve
Train Volume Formula and the Calculation of Valve
Proving Test Time.
4. Round up the time to the nearest second.
5. The test time calculated is the time you will enter into
the VPS Setup.
Calculation of Valve Train Volume
X = V1 + V2 + (A X L/144)
Calculation of Valve Proving Test Time
Test Time = 187,000 x (P x X)/C
Table 11. Valve Proving Test Time Symbols
and Descriptions.
NOTE: V1 is the outlet cavity of the upstream valve and V2
is the inlet cavity of the downstream valve.
NOTE: 10 seconds is the minimum test time allowed. If your
calculations are less than 10 seconds, enter 10
seconds.
For Example:
We have a 2.5 MBTU burner with 2 psi valve train inlet
pressure. The upstream valve is a proof-of-closure V5044 with
a solenoid V4295 valve downstream. We have a 2 in. NPT
pipe, 1-3/4 ft long, between the valves.
V1
V2
VP
SW.
M22778
L
X
INLET
OUTLET
P
C
D
LEGEND
V1 UPSTREAM VALVE
V2 DOWNSTREAM VALVE
D PIPE DIAMETER (IN INCHES.) USED TO DETERMINE A;
ARE FOUND IN TABLE III
L PIPE LENGTH (IN FEET)
P VALVE INLET PRESSURE (PSIG)
C BURNER MAX. FIRING (CFH)
X CALCULATED TEST VALVE TRAIN VOLUME
Symbol Unit Description
X
ft
3
Volume between the two valves to be
tested.
V
1
ft
3
Volume of upstream valve outlet cavity.
V2
ft
3
Volume of downstream valve inlet cavity.
L ft Length of pipe between valves.
D npt Pipe Size—used to define A
A
in.
2
Pipe Cross Section Area (from Table 15)
Test
Time
Seconds Minimum VPS test period.
P psi Gas inlet pressure to upstream valve.
C
ft
3
/hr
Burner Capacity.
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