Gas Trains - Beckett CG15 Manual

Install a Drip Leg in Gas
Supply Piping
Foreign matter could lodge in gas valve
cutoff seals, resulting in gas leak-through,
explosion or fi re.
Install a full-size drip leg or dirt pocket in the piping
directly ahead of the main shutoff valve to capture foreign
matter.

Gas Trains

Gas Leaks and Explosion
Hazards
Provide Over-pressure Protection
CSD-1 requires that if gas pressure entering the building
exceeds the rating of any gas train component an
overpressure protection device must be installed.
Standard – An Underwriters Laboratories (UL) listed
gas train is standard for the CG10 gas burner. This
confi guration also meets CSD-1 requirements.
Figures 8A and 8B for typical component layout.
Propane (LP) – When the correct propane restrictor is
added to a burner's gas pipe assembly it changes the
burner's gas pressure drop so that the propane pressure
drop is equal to the natural gas pressure drop of the same
BTU fi ring rate. That is why the Manifold to Furnace
Figure 7 - Typical Gas Piping Layout
METER
REGULATOR PG U
GAS UTILITY PIPING
CG15, CG25, CG50 Burner Manual
See
MSC
DRIP LEG
S
(IF USED)
FACILITY PIPING
Pressure Drop curves of Figures 14A, 14B, and 14C are
correct for both propane and natural gas. That is also
why a gas train adjusted for the burner's natural gas
requirements will be correctly adjusted for its propane
requirements. R. W. Beckett provides the same pressure
regulating safety shutoff valve in the gas train (usually a
Honeywell V4944B) for both natural gas and propane.
The valve is marked for natural gas due to its primary
usage in a pressure range normally used by natural gas
appliances. It is safe and effective for propane usage in
this design application.
Optional – Gas trains for IRI and FM are available and
must be specifi ed when ordering a burner.
Verify – Verify that the train components are not damaged
and all piping and fi ttings are clean inside and out. The
gas train is normally shipped as components and must be
assembled and installed at the site.
Vent Lines – Install vent lines to any gas valve component
that requires atmospheric air pressure to balance a
diaphragm. Vent lines must be run to the outdoors, with
the termination point away from fresh air intakes and
windows. The terminal opening must be fi tted with a wire
mesh screen to block insects and other contaminants
from entering the vent and must be mounted in such a
position that water, ice, dirt, or any other foreign matter
cannot infi ltrate and block the vent piping. Make sure the
fi nal assembly is anchored securely.
LGPS
U TC
SSOV1 2PRV
GAS TRAIN
Section: Connect Gas Piping
ABBREV. ITEM DESCRIPTION
HGPS HIGH GAS PRESSURE SWITCH
LGPS LOW GAS PRESSURE SWITCH
MSC MAIN SHUTOFF COCK
MLTC MAIN LEAK TEST COCK
PG PRESSURE GAUGE
S STRAINER
SSOV1 SAFETY SHUTOFF VALVE #1
TC TEST COCK
U UNION
2PRV TWO POSITION REGULATING VALVE
HGPS
TC
TC MLTC U
BURNER
BURNER
11