UHA L
OW
P
ROFILE
U
NIT
H
EATER
I
NSTALLATION
O
PERATION
AND
S
ERVICE
M
ANUAL
22
SECTION 8: GAS PIPING
A gas meter is connected to the service pipe by the
gas supply company. An existing meter should be
checked, preferably by the company, to ensure that
the meter is adequate for the rate of gas supply
required.
Installation pipes must be fitted in accordance with
local and national codes. Pipes of smaller size than
the heater inlet gas connection should not be used.
8.1 Connections
Connect the heater to the gas supply ensuring that
the final connections are as follows:
• Gas supply pipe work is run in medium or heavy
gauge tubing in compliance with local and
national codes.
• Meter and service must be large enough to
handle all the burners being installed plus any
other connected load. The gas pipe which feeds
the system must be large enough to supply the
required gas with a maximum pressure drop of
1/2" wc When gas piping is not included in the
layout drawing, contact the local gas supplier.
• An isolating valve and union connection should
be used and fitted into the supply adjacent to the
heater.
• A minimum 1/8" NPT plugged tapping
accessible for test connection must be installed
immediately upstream of the gas supply
connection to the heater.
• For suspended heaters, an approved metal
flexible connection between the isolating valve
and the heater may be used.
To reduce
pressure loss, use one pipe size larger than
the heater gas connection.
IMPORTANT
- The complete installation must be
purged and tested for gas soundness in accordance
with local and national codes.
Caution:
Do not high pressure (in excess of 1/2 psi
[14" wc]) test the gas piping with the burner
connected. Close manual shut-off valve during any
pressure testing equal to or less than 1/2 psi (14"
wc).
Check the pipe and tubing ends for leaks before
placing heating equipment into service. When
checking for gas leaks, use a soap and water
solution; never use an open flame.
Figure 15: Gas Connection
WARNING
Fire Hazard
Connect
g
as supply accordin
g
to Fi
g
ure 15.
Do not use
g
as supply pipe and electrical
connections to support heater’s wei
g
ht.
Gas can leak if not installed properly.
Failure to follow these instructions can
result in death, injury or property dama
g
e.
Gas Sh
u
t-off
V
al
v
e
Drip Leg
Cap
Union
Connection
Option B:
Medi
u
m or Hea
v
y
Ga
u
ge Pipe
Gas Connector
Option A:
Stainless Steel
Flexi
b
le Gas
Connector
Do not bend flexible
gas connector
sharply.
• Hold gas nipple
securely with pipe
wrench when attaching
the flexible gas
connector.
• Do not twist flexible
gas connector.
• Ensure all
joints are
gas tight.
