Desa WMN20A - Manual (Page 13)

www.desatech.com 124002-01C 13
* A CSA design-certified equipment shutoff
valve with 1/8" NPT tap is an acceptable al-
ternative to test gauge connection. Purchase
the optional CSA design-certified equipment
shutoff valve from your dealer.
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test Gauge Connection*
3/8" NPT
Pipe Nipple
Heater
Cabinet
Equipment
Shutoff
Valve*
3"
Min.
Natural Gas
From Gas
Meter
(4" W.C. to
10.5" W.C. Pressure)
Propane/LP
From External Regulator
(11" W.C. to 14" W.C.
Pressure)
Ground Joint
Union
IMPORTANT: Hold the pressure regulator
with wrench when connecting it to gas pip-
ing and/or fittings. Do not over tighten pipe
connection to regulator. The regulator body
could be damaged.
Tee Joint
Pipe
Nipple
Cap
Sediment
T
rap
INsTallaTIoN
Continued
CHECKING GAS CONNECTIONS
WARNING: Test all gas piping
and connections, internal and
external to unit, for leaks after
installing or servicing. Correct
all leaks at once.
WARNING: Never use an
open flame to check for a leak.
Apply a noncorrosive leak detec-
tion fluid to all joints. Bubbles
forming show a leak. Correct all
leaks at once.
CAUTION: For propane/LP
gas, make sure external regula-
tor has been installed between
propane/LP supply and heater.
See guidelines under Connect-
ing to Gas Supply, page 12.
PRESSURE TESTING GAS SUPPLY
PIPING SYSTEM
Test Pressures In Excess Of 1/2 PSIG
(3.5 kPa)
1. Disconnect appliance with its appliance
main gas valve (control valve) and equip-
ment shutoff valve from gas supply piping
system. Pressures in excess of 1/2 psig
will damage heater regulator.
2. Cap off open end of gas pipe where equip-
ment shutoff valve was connected.
3. Pressurize supply piping system by either
opening propane/LP supply tank valve
for propane/LP gas or opening main gas
valve located on or near gas meter for
natural gas or using compressed air.
4. Check all joints of gas supply piping sys-
tem. Apply a noncorrosive leak detection
fluid to all joints. Bubbles forming show a
leak.
5. Correct all leaks at once.
6. Reconnect heater and equipment shutoff
valve to gas supply. Check reconnected
fittings for leaks.
Figure 15 - Gas Connection
Pressure
Regulator
Connection Using Flexline
3/8" NPT/
1/2" Flare
90° Elbow
Flexline
See
illustration
above for
detail
Refer to connector's
instructions