Section 25 - Gas Piping Design; Gas Train Sizing; Installing The Gas Train; Gas Train Leak Check Procedure - Johnson Controls YORK YPC Series Installation Manual

FORM 155.17-N1
ISSUE DATE: 4/1/2013
Gas piping should be sized to provide the required
pres sure at the burner train inlet manual shut-off valve,
when operating at the maximum desired fuel input.
The assembled shipped loose gas trains supplied with
the burn er are not pres sure tested at Weishaupt, there-
fore, this re spon si bil i ty is up to the installing contrac-
tor. See Gas Train Leak Check procedure section in
this manual.

GAS TRAIN SIZING

BURNER SIZE
G3
G5, 30/2, 40/1
G7, 8, 40/2, 50/1
G9, 10, 50/2
G11, 60, 70

Installing the Gas Train

A drip leg must be installed in the gas supply system just
ahead of the burner gas train inlet. (See Figure 35 on page
74.) To ensure a consistent and reliable operation of
the burner, the gas safety shut-off valves (pilot and
main gas) must be mounted as close to the burner as
possible.
The gas valve train can be attached to the burner either
from the left or right side (on the ParaFlowTM chiller/
heat er units, it is usually on the outboard side of unit).
Before in stall ing the gas valve train, ensure that the
burner can be swung open for service.
Ensure that all gas train components are installed in
the correct order and that the flow direction is correct
for each component. Gas valves, actuators and gas
reg u la tors must only be installed in the vertical (up-
right) po si tion. The gas train should be supported in
several plac es.
For YORK ParaFlowTM chiller/heater orders,
Weishaupt sup plies the correct gas train size and com-
po nents with each ship ment. However, for general in-
formation and a bet ter understanding of the burner's
gas train, Figure 35 on page 74 shows the general
location of various com po nents in a typ i cal gas train.
The gas train in Figure 35 on page 74 will vary ac-
cord ing ly due to local codes, firing rates of the burner,
or gas sup ply pres sure.
JOHNSON CONTROLS
SECTION 25 – GAS PIPING DESIGN
DN - SIZE
DN40-1.5"
DN50-2.0"
DN65-2.5"
DN80-3.0"
DN100-4.0"
Gas Pilot Line: pipe into the main gas train line just
before the burner.

GAS TRAIN LEAK CHECK PROCEDURE

All manual shut-off and solenoid valves must be
closed for the test.
A test manometer is connected with a rubber hose and
hand pump using a tee piece in the hose, at the sole-
noid valve and at the pressure regulator or gas filter. If
this is not done, the neutral connection in the pressure
reg u la tor causes faulty measurements.
P
NOTES:
1. Filter with 1/4" test port connection.
2. Valve with 1/4" test port connection.
3. Valve with 1/4" test port connection.

FIGURE 34 - GAS TRAIN VALVE TESTING

The test pressure in the gas train should be twice
the operating pressure – at least 100 mbar (1.45 psi)
with nat u ral gas and 150 mbar (2.18 psi) with liq-
uid gas.
Before commencement of the test period, 5 minutes
must elapse so that false measurements are not caused
by tem per a ture variations. It can then be assumed that
there will not be significant pressure variations due to
temperature equalization.
The gas train is leak-free if the pressure drop after
the test period of 5 minutes is not more than 1 mbar
(0.4" W.C.).
If a leak is found, then the leak must be located by
brush ing with Nekal solution and sealed. The test pro-
cedure would then be repeated. This test is necessary
and is re quired for the Weishaupt burner commission-
ing report, which must be submitted to Weishaupt for
warranty.
2 3
LD05323
73
25