Smith Cast Iron Boilers GS110W GAS Supply Piping, Gas Pipe Capacity, Equivalent Pipe Length Chart

Page 18 GS110 DIRECT VENT BOILER INSTALLATION AND OPERATION INSTRUCTIONS

GAS SUPPLY PIPING

The GS110 hot water boiler comes from the factory ready to be piped to the gas supply. The gas supply can be piped from the left or right side of the boiler.

GS110
Section	Connection
Size	Tapping
3	1/2"
4	1/2"
5	1/2"
6	3/4"
7	3/4"

If for any reason the boiler is not for the type of gas available at the installation site, call the nearest Smith Cast Iron Boiler distributor to resolve the problem.

Figure 18 depicts the proper way to connect the boiler to the gas supply piping. The manual shut-off valve MUST be installed in the supply piping. It should be approximately 5 feet above the floor. Provide a sediment trap/drip leg at the bottom of the vertical section of the gas supply pipe. A ground joint union should be installed between the boiler gas controls and the supply piping. Each of these items is needed to ensure long life and ease of servicing. Always use a pipe sealant that is suitable for use with LP gas.

Figure 18 - Gas Supply Piping

CAUTION: Always use a wrench on the gas valve body when making gas connections to it. Never over-tighten the piping entering the gas valve body or the gas valve will be damaged!

Table 8 should be used to ensure that the gas supply piping is sized properly. If more than one appliance is supplied by the same supply pipe, the piping must be sized based on the maximum possible demand. Do not neglect the pressure drop due to pipe fittings. Table 9 should be used in conjunction with Table 8 to ensure that the gas supply piping is sized properly.

Safe lighting and other performance criteria were met
with the gas manifold and control assembly provided on
the boiler when the boiler underwent tests specified in
ANSI Z21.13. All gas connections MUST be leak tested
before putting the boiler into operation.
Table 8 - Gas Pipe Capacity
Nominal				Pipe length in feet
Iron Pipe	10	20	30	40	50	60	80	100	150
Size, (in)			Gas pipe Capacity (ft3/hr)
3/4″	278	190	152	130	115	105	90	79	64
1″	520	350	285	245	215	195	170	150	120
11/4″	1050	730	590	500	440	400	350	305	250
11/2″	1600	1100	890	760	670	610	530	460	380

Note: Maximum pipe capacity in ft3/hr is based on a 0.60 specific gravity gas at a pressure of 0.5 psig and a 0.3" WC pressure drop.

Table 9 - Equivalent Pipe Length Chart
Nominal				Type of pipe fitting
		90° Elbow		Tee	Gas Valve
Iron Pipe						Gas Cock
				(branch flow)	(full port)
Size, (in)
			Equivalent length of pipe fitting in feet
3/4″		2.6		5.2	0.6	1.5
1″		3.5		6.9	0.8	1.9
1	″	4.0		8.0	0.9	2.3
1 /4
1	″	5.2		10.3	1.2	3.0
1 /2
Whenever the gas supply piping is pressure tested the
boiler gas controls must be protected. If the test pres-
sure is equal to, or less than 1/2 psig (3.5 kPa) isolate
the boiler by closing it's manual shut off valve, see
Figure 18. If the test pressure is greater than 1/2 psig
(3.5 kPa), disconnect the boiler and it's individual shut-
off valve from the gas supply piping.
WARNING: Never use an open flame to test for
gas leaks. Always use an approved leak
detection method. Failure to comply with this
WARNING could result in an explosion!
ELECTRICAL WIRING
CAUTION: Label all wires prior to disconnection
when servicing controls. Wiring errors can cause
improper and dangerous operation!
ATTENTION: Au moment de l'entretien des
commandes, étiquetez tous les fils avant de les
débrancher. Des erreurs de câblage peuvent
entraîner un fonctionnement inadéquat et
dangereux. S'assurer que l'appareil fonctionne
adéquatement une fois l'entretirn terminé.
The electrical connections to this boiler/water heater
must be made in accordance with all applicable local
codes and the latest revision of the National Electrical
Code, ANSI /NFPA-70. Installation should also conform
with CSA C22.1 Canadian Electrical Code Part I if