Burnham 8H manual Equivalent Lengths of Standard Pipe Fittings & Valves

Table 6: Maximum Capacity of Schedule 40 Pipe in CFH for 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
Table 7: Equivalent Lengths of Standard Pipe Fittings & Valves
Pipe		I.D.			Valves (Fully Open)						Threaded Fittings
							Swing	90°		45°		90° Tee, Flow			90° Tee, Flow
Size	(Inches)		Gate		Globe	Angle
							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		1.6			2.3		6.9

Table 8: Specific Gravity Correction Factors

Specific	Correction	Specific	Correction
Gravity	Factor	Gravity	Factor
0.50	1.10	1.30	1.07
0.55	1.04	1.40	1.04
0.60	1.00	1.50	1.00
0.65	0.96	1.60	0.97
0.70	0.93	1.70	0.94
0.75	0.90	---	---
0.80	0.87	---	---

C.Pressure Test. The boiler and its gas connection must be leak tested before placing boiler in operation.

1.Protect boiler gas valve. For all testing over ½ psig, boiler and its individual shut-off valve must be disconnected from gas supply piping. For testing at ½ psig or less, isolate boiler from gas supply piping by closing boiler’s individual manual shut-off valve.

2.Locate leaks using approved combustible gas detector, soap and water, or similar nonflammable solution.

WARNING

Do not use matches, candles, open flames, or other ignition source.

Figure 24: Recommended Gas Piping

30