Lochinvar 497 - 2067 Gas connections continued, B, C, Gas train and controls, 2_Gastrain drawing

3 Gas connections (continued)

Gas connection

All gas connections must be made with pipe joint compound resistant to the action of liquefied petroleum (L.P.) and natural gases. All piping must comply with local codes and ordinances. Piping installations must comply with approved standards and practices.

1.Make sure gas line is a separate line direct from the meter unless the existing gas line is of sufficient capacity. Verify pipe size with your gas supplier.

2.Use new, properly threaded black iron pipe free from chips. If you use tubing, make sure the ends are cut square, deburred and clean. Make all tubing bends smooth and without deformation. Avoid flexible gas connections. Internal diameter of flexible lines may not provide unit with proper volume of gas.

3.Install a manual main gas shutoff valve at the unit’s gas inlet, outside of the unit.

4.Run pipe or tubing to the unit’s gas inlet. If you use tubing, obtain a tube to pipe coupling to connect the tubing to the unit’s gas inlet.

5.Install a sediment trap in the supply line to the unit’s gas inlet (see FIG. 3-1).

6.Apply a moderate amount of good quality pipe compound (do not use Teflon tape) to pipe only, leaving two end threads bare.

7.Remove seal over gas inlet to unit.

8.Connect gas pipe to inlet of unit. Use wrench to support gas manifold on the unit.

9.For L.P. gas, consult your L.P. gas supplier for expert installation.

10.Ensure that all air is completely bled from the gas line before starting the ignition sequence. Start up without properly bleeding air from the gas line may require multiple reset functions of the ignition control module to achieve proper ignition.

Do not have any open flame in proximity to WARNING the gas line when bleeding air from the gas

line. Gas may be present.

Gas train and controls

NOTICE	The gas train and controls assembly
	provided on this unit have been tested under
	the applicable American National Standard
	to meet minimum safety and performance
	criteria such as safe lighting, combustion
	and safety shutdown operation.

Installation & Service Manual

TABLE 3B

SUGGESTED GAS PIPE SIZE FOR

SINGLE UNIT INSTALLATIONS

Distance from Meter (in feet)

MODEL

	0 - 50	51 - 100	101 - 200	201-300 301-500
497	1 1/4''	1 1/4''	1 1/2''	2''	2''
647	1 1/4''	1 1/2''	2''	2''	2 1/2''
747	1 1/2''	2''	2''	2 1/2''	2 1/2''
987	2''	2''	2 1/2''	2 1/2''	3''
1257	2''	2 1/2''	2 1/2''	3''	3''
1437	2 1/2''	2 1/2''	3''	3''	3 1/2''
1797	2 1/2''	3''	3''	3 1/2''	3 1/2''
2067	2 1/2''	3''	3''	3 1/2''	4''

For each elbow or tee, add equivalent straight pipe to total length from Table 3C.

TABLE 3C

FITTINGS TO EQUIVALENT STRAIGHT PIPE

Diameter
Pipe	3/4	1	1 1/4	1 1/2	2	3	4	5
(inches)
Equivalent
length of	2	2	3	4	5	10	14	20
Straight Pipe
(feet)

Water heater models do not have downstream test valves, but the rest of the gas train is represented by FIG. 3-2.

Figure 3-2_Gas train drawing

497 MODEL

COMBINATION

VALVE

DOWNSTREAM	COMBINATION	2067 MODEL
	VALVE
TEST VALVE

TO BURNERS

DOWNSTREAM

TEST VALVE

TO BURNERS

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