Watts AERCO Benchmark OMM-0136 - HIGH GAS PRESSURE TEST: BMK3000 - 6000 Only

Benchmark Platinum-Edge [II]: Operation-Service Manual
SECTION 5 – SAFETY DEVICE TESTING
OMM-0137_E • GF-211 • 12/13/2019 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 64 of 153
HIGH Gas Pressure Test Instructions: BMK750 – 2500
Figure 5-3c: BMK2500: HIGH Gas Pressure Fault Test
5.3.2 HIGH GAS PRESSURE TEST: BMK3000 – 6000 Only
To simulate a high gas pressure fault, refer to Figure 5-4a and 5-4b and perform the following
steps:
HIGH Gas Pressure Test Instructions: BMK3000 – 6000 ONLY
1. Shut off the external gas supply by closing the external gas supply ball valve.
2. Locate the port on the side of the High Gas Pressure switch and loosen the screw in the
port a few turns to open it. Do not completely remove the screw. Alternatively, you can
remove the 1/4-inch plug shown in Figure 5-4a and 5-4b and install a hose barb fitting in
that location.
3. Attach one end of the plastic tubing to the port or barb fitting and the other end to a 0 – 16”
W.C. (0 – 4.0 kPa) manometer.
4. Apply the reading of the manifold pressure taken in Step 21 of Section 4.4.1 (natural gas
units) or Step 21 of Section 4.4.2 (propane units) and plug it into the following formula,
which calculates the maximum allowable gas pressure:
BMK3000
Natural Gas Pressure → ______ x 1.5 = ______ max gas pressure
BMK4000
Natural Gas Pressure → ______ x 1.5 = ______ max gas pressure
BMK5000 &
6000
Natural Gas Pressure → ______ x 1.5 = ______ max gas pressure
Propane Gas Pressure → ______ x 1.5 = ______ max gas pressure
5. Remove the cover from the High Gas Pressure switch and set the dial indicator to 20
(the maximum).
6. Open the external gas supply ball valve upstream of the unit.
SSOV
TO
AIR/FUEL
VALVE
LOW GAS
PRESSURE
SWITCH
MANUAL
SHUT-OFF
VALVE
HIGH GAS
BALL VALVE
1/4” NPT
PLUG
(install
manometer
here for HIGH
GAS
PRESSURE
FAULT TEST)
NATURAL
GAS INLET
HIGH GAS PRESSURE
SWITCH
(P/N 22190 shown)