Bosch Appliances Essential Gas Piping and Connections for Bosch 125B NG Water Heater Installation

GAS PIPING, CONNECTIONS and Gas Regulator

Before connecting the gas supply, check the rating plate on the right side of the front cover to be sure that the heater is rated for the same gas to which it will be connected.

In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54.

In Canada: The Installation should conform with CGA B149 INSTALLATION CODES and /or local installation codes.

GAS LINE SIZING

FOR NATURAL GAS

Maximum Capacity of pipe in Cubic Feet of Gas per Hour for Gas Pressure of 0.5 Psig or less and a Pressure drop of 0.3 in Water Column.

(Based on a 0.60 Specific Gravity Gas) Btu numbers given in thousands.

Follow boxed numbers for piping just one Aquastar 125B (example: 3/4” B.I. Natural Gas pipe for 30 ft. will handle 152,000 btu’s). For multiple appliances combine the total btu input load and then refer to applicable chart below.

Nominal
Iron						Length of Black Iron Pipe, Feet
Pipe	Internal
Size,	Diameter
inches	inches	10	20	30	40	50	60	70	80	90	100	125	150 175 200

	1/4	0.364
	3/8	0.493
	1/2	0.622
	3/4	0.824
	1	1.049
1	1/4	1.380
1	1/2	1.610
	2	2.067
2	1/2	2.469

33.068

44.026

32	22	18	15
72	49	40	34
132	92	73	63
278	190	152	130
520	350	285	245

1050 730 590 500

1600 1100 890 760

3050 2100 1650 1450

4800 3300 2700 2300

8500 5900 4700 4100

17,500 12,000 9,700 8,300

14	12	11	11	10	9	8	8	7	6
30	27	25	23	22	21	18	17	15	14
56	50	46	43	40	38	34	31	28	26
115	105	96	90	84	79	72	64	59	55
215	195	180	170	160	150	130	120	110	100
440	400	370	350	320	305	275	250	225	210
670	610	560	530	490	460	410	380	350	320
1270	1150	1050	990	930	870	780	710	650	610
2000	1850	1700	1600	1500	1400	1250	1130	1050	980
3600	3250	3000	2800	2600	2500	2200	2000	1850	1700
7,400	6,80	6,200	5,800	5,400	5,100	4,500	4,100	3,800	3500

FOR LP GAS

Maximum Capacity of Pipe in Thousands of BTU per Hour of Undiluted Petroleum Gases (at 11 inches Water Column Inlet Pressure) (Based on a Pressure Drop of 0.5 Inch Water Column).

Nominal
Iron Pipe							Black Iron Pipe
Size,							Length of Pipe, Feet
Inches		10		20	30	40	50	60	70	80	90	100	125	150
	1/2		275	189	152	129	114	103	96	89	83	78	69	63
	3/4	567		693	315	267	237	217	196	185	173	162	146	132
1		107		732	590	504	448	409	378	346	322	307	275	252
1 1/4		220		149	121	103	913	834	771	724	677	630	567	511
1 1/2		330		229	185	155	141	127	118	108	102	976	866	787
2		622		433	346	299	264	239	220	204	192	1811	1606	1496

Maximum Capacity of Semi-Rigid

Tubing in Thousands of BTU per Hour of Undiluted Liquified Petroleum Gases (at 11 inches Water Column Inlet Pressure)

(Based on a Pressure Drop of 0.5 Inch Water Column)

								Copper
Outside							Length of Tubing, Feet
Diameter,
Inch		10		20	30		40	50	60	70	80	90	100
3/8		39		26	21		19	_	_	_	_	_	_
1/2		92		62	50		41	37	35	31	29	27	26
	5/8		199	131	107		90	79	72	67	62	59	55
	3/4	329		216		181	145	131	121	112	104	95	90
	7/8	501		346	277		233	198	187	164	155	146	138

*Source National Fuel Gas Code NFPA 54, ANSI Z223.1 - No Additional Allowance is necessary for an ordinary number of fittings

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