Patterson-Kelley MOD-04 ユーザーズマニュアル

 10 

 

 

 

Note:  Install a sediment trap (drip leg) and a union 
connection ahead of the primary manual shutoff valve 

on the boiler.  Gas piping should be installed in accor-
dance with National Fuel Gas Code, ANSI Z223.1, 
latest edition, and any other local codes which may 
apply; in Canada see CAN/CGA-B 149. 
 
Note:  See chart below for required pipe size, based on 
overall length of pipe from meter plus equivalent 
length of all fittings. Approximate sizing may be based 
on 1 cubic foot of natural gas per 1,000 Btu per hour 
input, i.e., 900,000 Btu per hour requires about 900 
cubic feet per hour.  (See Typical Boiler Operating 
Conditions, Section 4.3, for more information.) 
 

WARNING!  

All threaded connections must be made using a pipe 
compound that is resistant to the action of liquefied 
petroleum gases.  Do not use Teflon tape on gas line 
threads. 

 

 

 

 

 

 
Pipe Capacity for Natural Gas 
 

Equivalent Pipe Length

Maximum Capacity in Cubic Feet of Natural Gas per Hour 

Pressure Drop of 0.5 inch Water Column/Equivalent Length of 

Pipe (in feet) 

Nominal 

Iron 

Pipe 

Size 

(Inches) 

 

Internal 

Diameter 

(Inches) 

90º Ell 

(Feet) 

Tee 

(Feet) 

 

20 

 

40 

 

60 

 

80 

 

100 

 

150 

 

200 

1-1/4 

1.380 

3.45 6.9 

950 

      

1-1/2 

1.610 

4.02 8.04 

1,460 

990 

810 

    

2 

2.067 

5.17 

10.3 

2,750 1,900 1,520 1,300 1,150  950  800 

2-1/2  2.469 

6.16 

12.3 

4,350 3,000 2,400 2,050 1,850 1,500 1,280 

3 

3.068 

7.67 

15.3 

7,700 5,300 4,300 3,700 3,250 2,650 2,280 

4 

4.026 

10.1 

20.2  15,800 

10,900 8,800 7,500 6,700 5,500 4,600 

 
 

By Installer 

Remote Gas 

Shutoff (not 

supplied) 

Drip Leg 

Union 

Shutoff (on 

boiler) 

Gas Meter (not 
supplied)