Burnham ES2 manual Appendix C Gas Piping, Length W.c. Pressure Drop Feet

APPENDIX C – Gas Piping

ASSURE GAS PIPING IS LEAK FREE AND OF PROPER SIZE and type for the

connected load.

SHUT OFF MAIN GAS SUPPLY prior to

Table C-3: Specific Gravity Correction Factors For

Natural Gas

Specific Correction Specific Correction

Gravity Factor Gravity Factor

installing or servicing boiler gas piping.

1.	Determine the boiler’s maximum gas
	demand and minimum gas supply pressure
	(printed on the boiler’s rating label) and the
	demand of other gas appliances served by
	the same gas meter.
2.	Ensure that gas piping, fittings, and gas

0.501.10

0.551.04

0.601.00

0.650.96

0.700.93

0.750.90

0.800.87

0.850.81

0.900.82

1.000.78

1.100.74

1.200.71

1.300.68

1.400.66

meter capacities can supply the maximum

gas demand of all appliances at pressures

above their minimum allowable gas

pressure. Tables C-1 and C-2 provide typical

capacities of gas pipes and fittings.

3. Derate the gas flow through pipes by

multiplying by a correction factor in Table

C-3 based on the specific gravity of the gas.

4. For materials or conditions other than those

listed above, refer to the National Fuel Gas

Code, NFPA54/ANSI Z223.1, or size the system using standard engineering methods acceptable to authority having jurisdiction.

USE PROPER THREAD COMPONENTS on all gas connectors.

USE THREAD (JOINT) COMPOUNDS (pipe dope) rated for liquefied petroleum

gas.

Table C-1: Maximum Capacity of Schedule 40 Pipe in Cubic Feet Per Hour (CFH)*

Length		0.3” w.c. Pressure Drop				0.5” w.c. Pressure Drop
(Feet)	½	¾	1	1¼	½	¾	1	1¼
10	132	278	520	1050	175	360	680	1400
20	92	190	350	730	120	250	465	950
30	73	152	285	590	97	200	375	770
40	63	130	245	500	82	170	320	660
50	56	115	215	440	73	151	285	580
60	50	105	195	400	66	138	260	530
70	46	96	180	370	61	125	240	490
80	43	90	170	350	57	118	220	460
90	40	84	160	320	53	110	205	430
100	38	79	150	305	50	103	195	400

*1 CFH of Natural Gas is approximately equal to 1000 BTU/hr; 1 CFH of LP is approximately equal to 2500 BTU/hr.

Table C-2: Equivalent Lengths (ft) Of Standard Pipe Fittings & Valves

Pipe	Gate	Globe	Angle	Swing	90°	45°	90° ‘T’, Flow	90° ‘T’, Flow
Size				Check	Elbow	Elbow	Through Run	Through Branch
½”	0	19	9	4	2	1	1	3
¾”	0	23	12	5	2	1	1	4
1”	1	29	15	7	3	1	2	5
1 ¼”	1	39	20	9	4	2	2	7
1 ½”	1	45	22	11	5	3	3	8

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