Goodman Mfg ANSI Z21.47CSA-2.3 - Manual (Page 12)

12
G
AS
P
IPING
C
HECKS
T O PREVENT PROPERTY DAMAGE OR PERSONAL INJURY DUE TO FIRE ,
THE FOLLOWING INSTRUCTIONS MUST BE PERFORMED REGARDING GAS
CONNECTIONS AND PRESSURE TESTING :
• T HE UNIT AND ITS GAS CONNECTIONS MUST BE LEAK TESTED
BEFORE PLACING IN OPERATION . B ECAUSE OF THE DANGER OF
EXPLOSION OR FIRE , NEVER USE A MATCH OR OPEN FLAME TO TEST
FOR LEAKS . N EVER EXCEED SPECIFIED PRESSURES FOR TESTING .
H IGHER PRESSURE MAY DAMAGE GAS VALVE AND CAUSE
OVERFIRING WHICH MAY RESULT IN PREMATURE HEAT EXCHANGE
FAILURE .
• T HIS UNIT AND ITS SHUT ‐ OFF VALVE MUST BE DISCONNECTED FROM
THE GAS SUPPLY DURING ANY PRESSURE TESTING OF THAT SYSTEM
AT TEST PRESSURES IN EXCESS OF 1/2 PSIG (3.48 K P A ).
• T HIS UNIT MUST BE ISOLATED FROM THE GAS SUPPLY SYSTEM BY
CLOSING ITS MANUAL SHUT ‐ OFF VALVE DURING ANY PRESSURE
TESTING OF THE GAS SUPPLY PIPING SYSTEM AT TEST PRESSURES
EQUAL TO OR LESS THAN 1/2 PSIG (3.48 K P A ).
CAUTION
T O AVOID PROPERTY DAMAGE OR PERSONAL INJURY , BE SURE THERE IS
IN THE VICINITY DURING AIR BLEEDING . NO OPEN FLAME
WARNING
There will be air in the gas supply line after testing for leaks
on a new installation. Therefore, the air must be bled from
the line by loosening the ground joint union until pure gas is
expelled. Tighten union and wait for five minutes until all gas
has been dissipated in the air. Be certain there is no open
flame in the vicinity during air bleeding procedure. The unit is
placed in operation by closing the main electrical disconnect
switch for the unit.
PROPANE GAS INSTALLATIONS
T O AVOID PROPERTY DAMAGE , PERSONAL INJURY OR DEATH DUE TO
FIRE OR EXPLOSION CAUSED BY A PROPANE GAS LEAK , INSTALL A GAS
DETECTING WARNING DEVICE . S INCE RUST CAN REDUCE THE LEVEL OF
ODORANT IN PROPANE GAS , A GAS DETECTING WARNING DEVICE IS THE
ONLY RELIABLE WAY TO DETECT A PROPANE GAS LEAK . C ONTACT A
LOCAL PROPANE GAS SUPPLIER ABOUT INSTALLING A GAS DETECTING
WARNING DEVICE .
WARNING
IMPORTANT NOTE: Propane gas conversion kits must be
installed to convert units to propane gas.
All propane gas equipment must conform to the safety
standards of the National Board of Fire Underwriters (See
NBFU Manual 58). Line pressure 11.3 - 14” w.c.
For satisfactory operation, propane gas manifold pressure
must be within 9.7 - 10.3 inches w.c. for high fire and within
6.7 - 7.3 inches w.c. low fire at the manifold with all gas appli-
ances in operation. Maintaining proper gas pressure depends
on three main factors:
1. Vaporization rate, which depends on (a) temperature
of the liquid, and (b) wetted surface area of the
container or containers.
2. Proper pressure regulation.
3. Pressure drop in lines between regulators, and
between second stage regulator and the appliance.
Pipe size required will depend on length of pipe run
and total load of all appliances.
T
ANKS AND
P
IPING
Complete information regarding tank sizing for
vaporization, recommended regulator settings and pipe
sizing is available from most regulator manufacturers and
propane gas suppliers.
Since propane gas will quickly dissolve white lead or most
standard commercial compounds, special pipe dope
must be used. Shellac base compounds resistant to the
actions of liquefied petroleum gases such as Gasolac
® ,
Stalactic ® , Clyde’s ® or John Crane ® are satisfactory.
See following figure for typical propane gas piping.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
TYPICAL PROPANE GAS PIPING
R
OOF
T
OP
L
OCATION AND
I
NSTALLATION
The gas supply piping location and installation for roof top
units must be in accordance with local codes or, in the ab-
sence of locals codes, with ordinances of the latest edition of
the National Fuel Gas Code (ANSI Z223.1).
A manual gas shutoff valve must be field installed external to
the roof top unit. In addition, a drip leg must be installed near
the inlet connection. A ground joint union connection is re-
quired between the external shutoff valve and the unit con-
nection to the gas valve to permit removal of the burner as-
sembly for servicing.
1. Route gas piping to unit so that it does not interfere
with the removal of access panels. Support and align
piping to prevent strains or misalignment of the
manifold assembly.
2. All units are furnished with standard female NPT pipe
connections. Connection pipe size is 3/4" NPT. The
size of the gas supply piping to the unit must be based
on length of run, number of units on the system, gas
characteristics, BTU requirement and available supply
pressure. All piping must be done in accordance with
local codes or, in the absence of local codes, with the
latest edition of the National Fuel Gas Code (ANSI
Z223.1).