Size And Install Gas Piping; Injury, Death Or Substantial Property Damage; Personal Injury - Weil-McLain PFG 7 Series Installation & Operation Manual

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Size and install gas piping

In sizing the gas piping, the following factors should
be considered.
a) Diameter and length of the gas supply piping.
b) Number of fittings.
c) Maximum gas consumption (including any pos-
d) Allowable loss in gas pressure from gas meter out-
1. Size natural gas piping from the following table. Piping
must be sized to provide proper inlet gas pressure to the
gas valve when boiler is operating at rated input. For
natural gas, inlet gas pressure to gas valve should be a
minimum of 5 inches water column and a maximum of 13
inches water column. If inlet natural gas pressure exceeds
13 inches water column, a 100 percent lock-up type gas
pressure regulator of adequate size must be installed in gas
supply piping and adjusted to prevent pressure in excess
of 13 inches water column.
To obtain cubic feet per hour, divide the input (Btu per
hour) by the heating value (Btu per cubic foot).
Pipe delivery schedule
. PFG 6 thru 8 only (and no damper on PI boilers) - for
propane gas, inlet gas pressure to gas valve should be
11 to 13 inches water column. The gas pressure regula-
tor (furnished by the gas supplier) must be adjusted
to provide lock-up pressures not exceeding 13 inches
water column. Select the pipe size, tanks and regulators
as required.
10
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Fired ater oiler
sible future expansion).
let to boiler. For pressure drops, see ANSI Z3-1
latest edition. Canadian installations must comply
with CAN/CSA B149.1 or . Installation Codes.
— B M
oiler anual
If boiler is to be propane fired, a conversion
kit must be used. Failure to use kit or to
properly install kit will result in severe
personal injury, death or substantial
property damage.
3. Remove jacket door and connect from gas valve to
gas meter.
Use a street elbow or an elbow and close
nipple at the inlet connection of the gas valve to run
gas piping through opening in jacket side panel.
4. Follow good piping practices.
5. Pipe joint compound (pipe dope) must be resistant
to corrosive action of liquefied petroleum gases and
applied sparingly only to male threads of pipe joints.
6. A drip leg must be installed at inlet of gas connection to
boiler. Where local utility requires drip leg be extended
to the floor, use an appropriate length of pipe between
the cap and tee.
7. A ground joint union must be installed in the piping
to provide for servicing (see Figure 5).
8. Install manual shut-off valve outside boiler jacket as
shown in Figure 5 when required by local codes.
9. Piping must be supported by hangers, not by the boiler
or its accessories.
10. In Canada only - when manual main shut off valve is
used, it must be identified by installer.
11. Purge all air from the supply piping.
Before starting the boiler, and during
initial operation, smell near the floor and
around the boiler for gas odorant or any
unusual odor. Remove boiler front door
and smell interior of boiler enclosure. Do
not proceed with startup if there is any
indication of a gas leak. Repair any leak
at once.
1. Before placing boiler in operation, check boiler and its
gas connection for leaks.
a) If test pressure is less than 13.0 inches water column
then close manual main shut-off valve.
b) If test pressure is greater than 13.0 inches water column
then boiler and gas valve must be disconnected from
gas supply piping.
Do not check for gas leaks with an open
flame - use bubble test. Failure to do so
can cause severe personal injury, death or
substantial property damage.
PFG-8, as required by ANSI Z1.13/CSA 4.9, is equipped
with a manual test valve as shown in Figure 5a. Close
this valve to test boiler gas valve without supplying gas
to the manifold.
Part Number 550-110-641/0605