Burnham PVG manual Valves Fully Open

Table 7: Maximum Capacity of Schedule 40 Pipe in CFH* For Natural Gas Pressures of 0.5 psig or Less

Length		0.3 inch w.c. Pressure Drop					0.5 inch w.c. Pressure Drop
[Feet]	½		¾	1	1¼	½		¾	1	1¼
10	132		278	520	1,050	175		360	680	1,400
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 1 MBH; 1 CFH of LP is approximately equal to 2.5 MBH; con- tact your gas supplier for the actual heating value of your gas.

B.Connect boiler gas valve to gas supply system.

WARNING

Failure to use proper thread compounds on all gas connectors may result in leaks of flammable gas.

WARNING

Gas supply to boiler and system must be absolutely shut off prior to installing or servicing boiler gas piping.

1.Use methods and materials in accordance with local plumbing codes and requirements of gas supplier. In absence of such requirements, follow National Fuel Gas Code, NFPA 54/ANSI Z223.1.

2.Use thread (joint) compounds (pipe dope) resistant to action of liquefied petroleum gas.

3.Install sediment trap, ground-joint union and manual shut-off valve upstream of boiler gas control valve and outside jacket. See Figure 13.

Figure 13: Recommended Gas Piping

Table 8: Equivalent Lengths of Standard Pipe Fittings & Valves

VALVES FULLY OPEN

Pipe	I.D.	Gate	Globe	Angle	Swing	90°	45°	90° Tee, Flow	90° Tee, Flow
Size	Inches				Check	Elbow	Elbow	Through Run	Through Branch
½”	0.622	0.35	18.6	9.3	4.3	1.6	0.78	1.0	3.1
¾”	0.824	0.44	23.1	11.5	5.3	2.1	0.97	1.4	4.1
1”	1.049	0.56	29.4	14.7	6.8	2.6	1.23	1.8	5.3
1¼”	1.380	0.74	38.6	19.3	8.9	3.5	1.60	2.3	6.9

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