Williams AC2030 Owner's Manual page 17

Connections between the manual shutoff valve and burner
control assembly can be made with an A.G.A./C.G.A. design
certified flexible connector if allowed by local codes. Drip leg
and ground joint unions are still required.
Tighten all joints securely.
Test all piping for leaks. When checking gas piping to the
furnace with gas pressure less than 1/2 PSI, shut off manual
gas valve to the furnace. If gas piping is to be checked with
the pressure at or above 1/2 PSI, the furnace and manual
shutoff valve must be disconnected during testing. (SEE
WARNING). Apply soap solution (or a liquid detergent) to
each joint. Bubbles forming indicate a leak. Correct even the
slightest leak at once.
FIGURE 14 – Gas Piping
GROUND JOINT UNION
PIPED GAS SUPPLY
3ʺ (76.2 MM) MINIMUM
GROUND JOINT UNION
GAS
VALVE MANUAL
SHUT-OFF VALVE
RISER
3ʺ (76.2 MM)
MINIMUM
CAP
2
NIPPLE
GROUND JOINT
UNION
TUBING GAS SUPPLY
3ʺ (76.2 MM) MINIMUM
1
CAUTION: All bends in metal tubing must be smooth.
CAUTION: Shut off the main gas supply before removing the end cap to prevent
2
gas from filling the work area. Test for gas leakage when installation is complete.
MANUAL SHUT-OFF VALVE
DROP
HORIZONTAL
GAS
VALVE
TEE
CAP
2
FITTING
NIPPLE
PIPED GAS SUPPLY
DROP
MANUAL SHUT-OFF VALVE
HORIZONTAL
1
RISER
GAS
VALVE
TEE
CAP
2
FITTING
NIPPLE
WARNING: Danger of property damage, bodily injury or
death. Never use a match or open flame to test for leaks.
Never exceed specified pressures for testing. Higher
pressures may damage the gas valve and cause over-
firing which may result in component(s) failure. Never
attempt start-up of unit before thoroughly ventilating
the area and smelling near the floor for gas odor.
FIGURE 15 – Proper Piping Practice
1/8ʺ NPT
PLUGGED
HOLE FOR
TEST
GUAGE
2 THREADS EXPOSED
PROPER PIPE
TRHEADING
SEALANT THIN
ENOUGH TO SHOW
THREADS
DAMAGED
THREADS
INCORRECT
TRHEADING
OVER-THREADED
SEALANT
PAST TIP
SEALANT
TOO THICK
17