UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 9: GAS PIPING
Fire Hazard
Connect gas supply according to Figure 14.
Do not use gas supply pipe and electrical connections to support the heater’s weight.
Gas can leak if not installed properly.
Failure to follow these instructions can result in death, injury or property damage.
WARNING
Explosion Hazard
Leak test all components of gas piping before operation.
Gas can leak if piping is not installed properly.
Do not high pressure test gas piping with heater connected.
Failure to follow these instructions can result in death, injury or property damage.
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. Gas lines must meet applicable codes:
United States: Flexible stainless steel gas hose (US models) is certified per the standard for connectors for gas applications. ANSI Z21.21/CSA 6.10 – latest revision.
Canada: Rubber type 1 gas hose (Canadian models) is certified as being in compliance with the
20 of 47
standard for elastomeric compostite hose and hose couplings for conducting propane and natural gas, CAN/CGA 8.1 – latest revision.
9.1 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
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.
