4
Midco
International
Inc.
8470 23
Pipe
Type
Approx. Capacity - MBH
Size
of Gas
Length of Pipe
10
20
40
60
100
3/4″
NATURAL
275
200
130
100
PROPANE
450
300
200
165
125
1″
NATURAL
520
350
245
195
150
PROPANE
800
550
385
300
235
1-1/4″
NATURAL
800
730
500
400
300
PROPANE
800
790
630
480
1-1/2″
NATURAL
800
760
610
460
PROPANE
800
800
725
2″
NATURAL
800
800
800
PROPANE
800
Piping
Continued
Input A
djust
er S
etting in Number of
T
u
rns F
rom F
ull Closed
Manifold Gas Pressure in Inches W. C.
Input in MBH
100 200 300 400 500 600 700 800
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PROPANE
PROPANE Gas
2,500 BTU / Cu. Ft.
(with 3/8" Main Gas Port
8.0
9.0
10.0
11.0
Capacities shown are for
total pressure drop of 0.3
″
W.C. For higher permissible
pressure drops consult your
fuel supplier.
Source
: Gas
Engineers Handbook-1974
Industrial Press Inc. NY, NY
Table 1 -
Supply Pipe Capacities
in MBH
Table 2 -
Firing Rate Curves -
Propane and Natural
Gas Pressure at Main automatic Valve (Inches Water Column)
Input A
djust
er S
etting in Number of
T
u
rns F
rom F
ull Closed
Input in MBH
100 200 300 400 500 600 700 800
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NATURAL
NATURAL Gas
1,000 BTU / Cu. Ft.
(with 5/8" Main Gas
Port)
6.0
6.5
7.0
3.0 3.5 4.0 4.5 5.0 5.5
Firing Rate in MBH (800 MBH = 800,000 BTU/Hr)
