Measuring The Inlet Gas Pressure - Navien NCB-190/060H Installation & Operation Manual

Maximum Liquefied Propane Delivery Capacity
In Thousands of BTU/H (0.5 in WC pressure drop)
Length (including fittings)
Pipe Size
10 ft 20 ft
(3 m) (6 m)
/ in 291 200
1
2
/ in 608 418
3
4
1 in 1,150 787
1 / in 2,350 1,620 1,300 1,110 985
1
4
1 / in 3,520 2,420 1,940 1,660 1,480 1,340 1,230 1,140 1,070 1,010 899
1
2
2 in 6,790 4,660 3,750 3,210 2,840 2,570 2,370 2,200 2,070 1,950 1,730 1,570 1,440

4.2 Measuring the Inlet Gas Pressure

WARNING
The boiler cannot function properly without sufficient inlet gas pressure. Measuring the inlet gas pressure
should be performed by a licensed professional only.
The inlet gas pressure must be maintained between 3.5 in and 10.5 in WC for natural gas and between 8.0 in
●
and 13.5 in WC for liquefied propane.
The appliance and its individual shutoff valve must be disconnected from the gas supply piping system during
●
any pressure testing of that system at test pressures in excess of
The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff
●
valve during any pressure testing of the gas supply piping system at test pressures equal to or less than
(3.5 kPa).
If gas pressure is out of the acceptable range or an excessive pressure drop is observed, contact the
Note
gas supplier or a qualified installer to supply proper gas pressure to the unit.
30 ft 40 ft 50 ft 60 ft
(9 m) (12 m) (15 m) (18 m)
160 137 122 110
336 287 255 231
632 541 480 434
892
80 ft 100 ft 125 ft 150 ft
(24 m) (30 m) (38 m) (45 m)
101 94 89 84
212 197 185 175
400 372 349 330
821 763 716 677
/ psi (3.5 kPa).
1
2
175 ft 200 ft 250 ft
(53 m) (60 m) (76 m)
74 67 62
155 140 129
292 265 243
600 543 500
814 749
/ psi
1
2
Connecting the Gas Supply 55