Lochinvar 399 Check inlet gas supply, Nominal Natural Gas Pipe Capacity Chart, Iron Pipe, Inches

Installation & Operation Manual

7Gas connections (continued)

Table 7A Natural Gas Pipe Size Chart

Nominal					Natural Gas Pipe Capacity Chart										Maximum
Iron Pipe															Capacity of Pipe
					Length of Pipe in Straight Feet
Size															in Thousands of
															Btu/hr per hour
(inches)	10	20	30	40	50	60	70	80	90	100	125	150	175	200
															for gas pressures
1/2	175	120	97	82	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	of 14 Inches
															Water Column
3/4	369	256	205	174	155	141	128	121	113	106	95	86	79	74
															(0.5 PSIG) or less
1	697	477	384	328	292	267	246	236	210	200	179	164	149	138	and a pressure
1-1/4	1400	974	789	677	595	543	502	472	441	410	369	333	308	287	drop of 0.5 Inch
															Water Column
1-1/2	2150	1500	1210	1020	923	830	769	707	666	636	564	513	472	441
															(Based on NAT
2	4100	2820	2260	1950	1720	1560	1440	1330	1250	1180	1100	974	871	820
															GAS, 1025 Btu/hr
2-1/2	6460	4460	3610	3100	2720	2460	2310	2100	2000	1900	1700	1540	1400	1300	per Cubic Foot of
															Gas and 0.60
3	11200	7900	6400	5400	4870	4410	4000	3800	3540	3330	3000	2720	2500	2340
															Specific Gravity)
4	23500	16100	13100	11100	10000	9000	8300	7690	7380	6870	6150	5640	5130	4720

Check inlet gas supply

NOTICE

CSA or UL listed flexible gas connections are acceptable, but you must exercise caution to ensure that the line has adequate capacity to allow your boiler to fire at full rate. Consult with local codes for proper installation or service procedures.

4.	Slowly turn on the gas supply at the field installed
	manual gas valve.
5.	Turn the power switch to the “ON” position.
6.	Adjust the temperature set point on the control panel of
	the SMART SYSTEM control module to call for heat.
7.	Observe the gas supply pressure as the burner fires at

￿WARNING DO NOT adjust or attempt to measure gas valve outlet pressure. Attempting to alter

or measure the gas valve outlet pressure could result in damage to the valve, causing potential severe personal injury, death, or substantial property damage.

The gas piping must be sized for the proper flow and length of pipe, to avoid excessive pressure drop. Both the gas meter and the gas regulator must be properly sized for the total gas load.

If you experience a pressure drop greater than 1 inch w.c. (249 Pa), the meter, regulator, or gas line is undersized or in need of service. Perform the steps below when checking inlet gas supply:

1.Turn the main power switch to the “OFF” position.

2.Shut off gas supply at the manual gas valve in the gas piping to the appliance.

3.On Models 399 - 500 loosen the set screw one (1) full turn from inside the pressure tap on top of the gas valve. On Models 600 - 800 remove the 1/8" (3 mm) pipe plug on the inlet flange to the valve and install a suitable 1/8" (3 mm) fitting (field supplied) for the manometer tubing. Place the tubing of the manometer over the tap once the set screw is loosened or the 1/8" (3 mm) fitting is installed (depending on model) as shown in FIG.’s 7-5 thru 7-7 on page 44.

	100% of rated input. Percent of burner input will be
	displayed on the control panel.
8.	Ensure inlet pressure is within specified range.
	Minimum and maximum gas supply pressures are
	specified in this section of the manual.
9.	If gas supply pressure is within normal range and no
	adjustments are needed, proceed on to Step 11.
10.	If the gas pressure is out of range, contact the gas utility,
	gas supplier, qualified installer or service agency to
	determine the necessary steps to provide proper gas
	pressure to the control.
11.	Turn the power switch to the “OFF” position.
12.	Shut off the gas supply at the manual gas valve in the gas
	piping to the appliance.
13.	Remove the manometer from the pressure tap on top of
	the gas valve. On Models 399 - 500 re-tighten the set
	screw inside the pressure tap. On Models 600 - 800
	remove the 1/8" (3 mm) field supplied fitting and
	reinstall the pipe plug removed in Step 3.

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