Section Iv: Gas Piping - Weil-McLain CG Series Manual

Section IV: Gas Piping
Size gas piping considering:
a. Diameter and length of gas supply piping.
b. Number of fittings.
c. Maximum gas consumption (including any possible fu¬
ture expansion).
d. Allowable loss in gas pressure from gas meter outlet to
boiler. For pressure drops, see ANSI Z223.1-latest edition.
Canadian installations must comply with CAN/CGA
B149.1 or .2 Installation Codes.
1. For natural gas:
a) Refer to following tables, lb obtain cubic feet per hour,
divide the input by 1000.
b) Size for rated boiler input.
c) Inlet gas pressure: 5" W.C. minimum
13" W.C. maximum
d) Manifold gas pressure: 314" W.C.
e) Install 100% lock-up gas pressure regulator in supply
line if inlet pressure exceeds 13" W.C. Adjust for 13"
W.C. maximum.
PIPE DELIVERY SCHEDULE
* 0.60 Specific Gravity, 0.30 inches water column pressure drop.
NOTE: For additional piping schedules, see ANSI Z223.1-latest edition.
Canadian installations must comply with CAN/CGA B 149.1 or .2 Instal¬
lation Codes.
2. For propane gas:
a) Inlet gas pressure: 11" W.C. minimum
13" W.C. maximum
b) Manifold gas pressure: 10" W.C.
c) Gas pressure regulator provided by gas supplier must
be adjusted for maximum pressure of 13" W.C.
d) Contact gas supplier to size pipes, tanks and regulator.
3. Remove jacket door and refer to Figure 9 for gas piping.
4. Follow good piping practices.
5. Pipe joint compound (pipe dope) must be resistant to cor¬
rosive action of liquified petroleum gases and applied
sparingly only to male threads of pipe joints.
GAS SUPPLY PIPING
FIGURE 9
6. Install drip leg at inlet of gas connection to boiler. Whei
local utility requires drip leg be extended to the floor, uf
appropriate length of pipe between cap and tee.
7. Install ground joint union to provide for servicing, wht
required.
8. Install manual shut-off valve in gas supply piping outsic
boiler jacket when required by local codes or utility r
quirements.
9. Support piping by hangers, not by boiler or its accessorie
10. Purge all air from supply piping.
11. Before placing boiler in operation, check boiler and i
gas connection for leaks.
Do not check for gas leaks with;
open flame - use bubble te.<
Failure to do so can cause seve
personal injury, death or substa
tial property damage.
a) Close manual main shut-off valve during any pressu
testing at less than 13 inches water column.
b) Disconnect boiler and gas valve from gas supply pipi)
during any pressure test greater than 13 inches wat
column.
12. In Canada - when using manual main shutoff valve,
must be identified by installer.