Lochinvar 497 - 2067 Gas connections, Connecting to gas supply Gas piping, Gas pressure test

Installation & Service Manual

3 Gas connections

Connecting to gas supply Gas piping

Verify that the appliance is supplied with the type of gas specified on the rating plate. This appliance is configured for operation up to 2000 feet altitude. Consult factory for installations above 2000 feet elevation.

Inlet gas pressure: Measured at the inlet pressure tap on the appliance gas manifold. The pressure tap is located upstream of the combination gas valve(s).

See Table 3A for maximum and minimum inlet pressures. Do not exceed the maximum. Minimum inlet pressure is for the purpose of input adjustment.

TABLE 3A

INLET GAS PRESSURE

	NATURAL			LP
MODEL
	Max.	Min.	Max.		Min.
	w.c.	w.c.	w.c.		w.c.
497 - 747	14''	4.0''	14.0''		8.0''
987 - 2067	14''	4.5''	14.0''		8.0''

Manifold pressure: The gas regulator on the unit’s combination gas valve is adjustable to supply proper manifold pressure for normal operation.

NOTICE	If an inline high gas pressure regulator is
	used, it MUST BE of the lockup type and
	be located a minimum of 10 feet from the

To safely operate this unit, you must properly size the gas supply piping. See Tables 3B through 3D for piping and fitting requirements. Gas pipe size may be larger than heater connection.

The gas connection for Models 497 - 747 is 1 1/4'' NPT and on Models 987 - 2067 the gas connection to these units is 2'' NPT.

For ease of service, install a union.

Install a manual main gas shutoff valve, outside of the unit gas connection within six feet of the unit in accordance with the requirements of the National Fuel Gas Code, ANSI Z223.1.

You must provide a sediment trap (drip leg) in the inlet of the gas connection to the unit.

NOTICE	It is the installer’s responsibility to supply
	the sediment trap (drip leg).

The combination gas valves have an integral vent limiting device and do not require venting to atmosphere, outside the building. The unit will not operate properly if the reference hose is removed or a vent to atmosphere is installed.

Optional gas controls may require routing of bleeds and vents to the atmosphere, outside the building when required by local codes.

Figure 3-1_Gas line connection

appliance.	Failure to do so may result in
insufficient gas volume supplied to the
appliance.

If you must adjust regulator pressure, follow the instructions under Gas Manifold Pressure Adjustment on page 25. Do not increase regulator pressure beyond specified pressure setting.

Gas pressure test

COUPLING

UNION

MANUAL MAIN

SHUT OFF

VALVE

USE WRENCH

TO HOLD

SUPPLY PIPE

8"

MIN

1.The appliance must be disconnected from the gas supply piping system during any pressure testing of that system at a test pressure in excess of 1/2 PSIG (3.5 kPa).

2.The appliance must be isolated from the gas supply piping system by closing a manual shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 PSIG (3.5 kPa).

3.The appliance and its gas connection must be leak tested before placing it in operation.

NIPPLE

CAP

22