Patterson-Kelley TBIG-03 owner manual Gas Pressure Adjustment

Gemini™ Twin-Fuel Gas-Fired Boiler

Gas Pressure Adjustment

Test of Motorized Gas Valves

4.2GAS PIPING

Before making the gas hook-up, make sure the boiler is being supplied only with the fuels shown on the boiler nameplate. The boiler is designed to operate on vaporized natural gas and propane only. Do not use any type of liquid fuel. Do not attempt to fuel the boiler with MAPP gas, sewage gas, coal gas, or other fuels.

Gas train connection sizes are shown in the Gas Train Connection table on the previous page for the different models available.

The boiler shall be installed such that the gas ignition system components are protected from water (drip- ping, spraying, rain, etc.) during appliance operation and service (circulator replacement, control replace- ment, etc.).

The two gas pressure regulators supplied with the boiler are set during a factory fire-test to provide the proper pressure to the main burner: 6 inches W.C. in- let pressure to the regulators for both natural gas and propane.

The gas train components are designed to handle a maximum inlet pressure of 14 inches W.C.(1/2 psig). If the available gas pressure exceeds 14 inches W.C. on either the natural gas or propane supply a suitable intermediate gas pressure regulator of the "lock up" type must be provided to reduce the pressure to less than 14 inches W.C. All boilers are designed to oper- ate at rated input with a minimum inlet pressure of 6 inches W.C. with natural gas, 6 inches W.C. with LP gas.

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natural gas supply

remote gas shutoff	union
(not supplied)
drip leg	shutoff
	(on boiler)
propane	shutoff
supply
	(on boiler)
remote gas shutoff	union
(not supplied)
drip leg

Figure 4-2 Gas Supply Piping

(Refer to table above for connection sizes.)

Install a sediment trap (drip leg) and a union connec- tion ahead of the primary manual shutoff valves on the boiler as shown in the figure above.

All gas piping must be installed in accordance with National Fuel Gas Code, ANSI Z223.1, latest edition, and any other local codes which may apply; in Canada gas piping must be installed in accordance with CAN- B 149.

General Warning

Warning! All threaded connections must be made us- ing a pipe compound that is resistant to the action of liquefied petroleum gases. Do not use Teflon￿ tape on gas line threads.

The boiler and all gas piping connections must be pressure tested and must be checked for leaks before being placed into service. Test with compressed air or gas if possible.

The boiler must be disconnected at both boiler manual