National Products Series B GAS Supply Piping Procedure 1ÐCHECKING GAS Supply, ÐGas Pipe Sizes

3.Boiler installation site experiences gusting or high winds. A power venter can help prevent the boiler from short cycling due to gusting or high winds by providing vent exhaust pressures greater than the boiler's induced draft blower alone.

4.When installer or homeowner prefers a negative pressure vent system instead of a positive pressure vent system.

5.May be more cost effective than stainless steel venting, particularly at longer vent lengths.

The Fields Controls power vent kit includes either a SWG-II-4HD or SWG-II-5 power venter, a MG-1 4-in. barometric draft controller, and the CK-43D controls kit.

Confirm that installing a power venter is an option allowed by local codes. For installation information, follow specific Installation Instructions provided with power venter kit.

NOTE: Although the power venter is equipped with its own fan, the fan on the boiler MUST remain in place and unaltered when a power venter is used.

When sidewall venting, flue gases must be vented to a point in relation to the prevailing wind so they may freely disperse without being blown back at the building causing discoloration, or into the building through doors or windows causing odors. Also, under certain conditions flue gases will condense, forming moisture. In such cases, steps should be taken to prevent building materials at the vent terminal from being damaged by the exhausted flue gas.

When installing single wall galvanized vent pipe for power venting, follow specific power venter Installation Instructions for layout, location of barometric draft control, and termination connections. When joining and sealing single wall galvanized or Type-B vent piping, use RTV silicone sealant with a minimum temperature rating of 400°F. For 3-in vent pipe runs, begin with the female end of vent pipe over boiler's induced draft blower outlet. For 4-in. vent pipe runs, begin with the 3-in. to 4-in. increaser fitting (included in boiler parts bag) over induced draft blower outlet. Then follow by placing female end of 4-in. vent pipe over increaser fitting. When joining pieces of single wall galvanized vent pipe, a substantial bead of silicone should be used at the joint to insure a leak-proof connection.

GAS SUPPLY PIPING

PROCEDURE 1ÐCHECKING GAS SUPPLY

The gas pipe to boiler must be the correct size for length of run and for total Btuh input of all gas utilization equipment connected to it. See Table 5 for proper size. Be sure gas line complies with local codes and gas company requirements.

The boiler and its individual shutoff valve must be disconnected from gas supply piping system during any pressure testing of gas supply piping system at test pressures in excess of 0.5 psig (3.5 kPa).

The boiler must be isolated from gas supply piping system by closing its individual manual shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or less than 0.5 psig (3.5 kPa).

PROCEDURE 2ÐCONNECTING GAS PIPING

Refer to Fig. 6 for general layout at boiler. It shows the basic fittings needed. The gas line enters boiler from right side.

The following rules apply:

1.Use only those piping materials and joining methods listed as acceptable by the authority having jurisdiction or in the absence of such requirements, by the NFGC. In Canada, follow the CAN/CGA-B149.1 and .2 Installation Codes for Gas Burning Appliances and Equipment.

2.All pipe compound must be resistant to propane gas.

3.Install ground joint union in gas supply line between shutoff valve and boiler controls.

Table 5ÐGas Pipe Sizes

NATURAL GAS

Length			Pipe CapacityÐBtuh Input
of Pipe			Includes Fittings
(Ft)	1/2 in.		3/4 in.	1 in.	1-1/4 in.
20	92,000		190,000	350,000	625,000
40	63,000		130,000	245,000	445,000
60	50,000		105,000	195,000	365,000
		PROPANE GAS
Length			Pipe CapacityÐBtuh Input
			Includes Fittings
of Pipe
	Copper Tubing*			Iron Pipe
(Ft)	5/8 in.		3/4 in.	1/2 in.	3/4 in.
20	131,000		216,000	189,000	393,000
40	90,000		145,000	129,000	267,000
60	72,000		121,000	103,000	217,000

* Outside diameter.

NOTE: The length of pipe or tubing shown should be measured from gas meter or propane second-stage regulator.

MANUAL

SHUTOFF

VALVE

GROUND JOINT

UNION

AUTOMATIC

GAS VALVE

MANIFOLD

SEDIMENT TRAP

FLOOR LINE

A95148

Fig. 6ÐGas Piping at Boiler

Ð10Ð