Gas Supply Piping - Dunkirk 90-50 Installation, Operation & Maintenance Manual

installation
Attach combustion air intake piping to supplied Fernco 2" cou-
1.
pling on mixer. Attach vent piping to furnished 2" CPVC vent
tee on draft inducer outlet.
All pipe joints are to be water tight
Working from the boiler to the outside, cut pipe to required
2.
length(s).
Deburr inside and outside of pipe.
3.
Chamfer outside edge of pipe for better distribution of primer
4.
and cement.
Clean and dry all surfaces to be joined.
5.
Check dry fit of pipe and mark insertion depth on pipe.
6.
It is recommended that all pipes be cut,
prepared, and pre-assembled before
permanently cementing any joint.
Check gas supply
The gas pipe to your boiler must be the correct size for the length
of run and for the total Btu per hour input of all gas utilization
equipment connected to it. See Table #3 for the proper size (next
page). Be sure your gas line complies with local codes and gas
company requirements.
The boiler 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 ½ psig (3.5kpa).
The boiler 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 ½ psig (3.50ka).
MAxIMUM GAS SUPPLy
PRESSURE
MINIMUM GAS SUPPLy
PRESSURE
Connecting The gas piping
Refer to Figure 12 (on following page) for the general layout at the
boiler. It shows the basic fittings you will need. The gas line enters
the boiler from the right side jacket panel. The boiler may receive
the gas supply pipe through the left side, or rear jacket panel by
relocating the gas valve connector and pipe assembly. The boiler
is equipped with a ½" NPT connection on the gas valve for supply
piping. The following rules apply:
CombusTion air and VenT pipe
NOTICE
NOTICE

gas supply piping

NATURAL PROPANE
GAS GAS
10" w.c. 14" w.c.
4" w.c. 10" w.c.
After pipes have been cut and pre-assembled, apply cement
7.
primer to pipe fitting socket and end of pipe to insertion mark.
Quickly apply approved cement to end of pipe and fitting
socket (over primer). Apply cement in light, uniform coat on
the inside of socket to prevent buildup of excess cement. Apply
second coat.
While cement is still wet, insert pipe into socket with ¼ turn
8.
twist. Be sure pipe is fully inserted into fitting socket.
Wipe excess cement from joint. A continuous bead of cement
9.
will be visible around perimeter of a properly made joint.
Handle pipe joint carefully until cement sets.
10.
Support combustion air and vent piping a minimum of
11.
every 5 feet using pre-formed metal hanging straps. Do not
rigidly support pipes. Allow movement due to expansion and
contraction.
Slope horizontal portion of combustion air and vent pipes
12.
toward boiler a minimum of ¼" per linear ft. (21mm/m) with
no sags between hangers.
Use appropriate methods to seal openings where vent and
13.
combustion air pipes pass through roof or side wall.
Use only those piping materials and joining methods listed
1.
as acceptable by the authority having jurisdiction, or in the
absence of such requirements, by the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and or the Natural Gas and Propane
Installation Code, CAN/CSA B149.1.
Use pipe joint compound suitable for liquefied petroleum gas
2.
on male threads only.
Use ground joint unions.
3.
Install a sediment trap upstream of gas controls.
4.
Use two pipe wrenches when making the connection to the gas
5.
valve to keep it from turning.
Install a manual shutoff valve in the vertical pipe about 5 feet
6.
above floor.
Tighten all joints securely.
7.
Propane gas connections should only be made by a licensed
8.
propane installer.
Two stage regulation should be used by the propane installer.
9.
Propane gas piping should be checked out by the propane
10.
installer.
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