Slant/Fin GXHA-200 - Manual (Page 6)

6 GALAXY STEAM BOILER
PIPING A LOW PRESSURE STEAM BOILER
Boilers must be piped with good engineering practice and must
conform to the requirements of ANSI/ASME Boiler and
Pressure Vessel Code section IV and to the authority having
jurisdiction.
NOTES:
1. Slant/Fin makes no recommendation, nor does Slant/Fin
imply that One Pipe Parallel and Counterflow Gravity
Condensate Return systems shown on page 7 are the pre-
ferred systems. These systems are merely two examples of
many possible systems. Determination of the proper system
is based upon the application and is therefore beyond the
scope of this instruction.
2. The 18" minimum height shown in figures 1-3, is the mini-
mum height between the top of the jacket of the boiler and
the 2-1/2" x 12" header centerline in the supply piping from
the boiler. It must NOT be confused with the minimum
height between the water level and the lowest return bend of
the steam supply main. This height is "H" as shown in fig-
ures 2 and 3.
The minimum height of "H" must be at least equal to the
sum of the pressure drop of the system plus three times the
friction loss of the wet return, but not less than 18" for a sys-
tem with a 1/8" psi steam pressure drop and not less than
28" for a system with a 1/2" psi steam pressure drop.
3. Modern steam boilers are smaller in water content than the
boilers that they replace, therefore a mechanical return sys-
tem (pump, receiver, etc.) must be employed if conditions
exist such that uniform condensate return flow to the boiler
cannot be maintained.
Pocketing of condensate and the inability to maintain the
correct minimum height between the steam supply main and
the water level in the boiler are but a few of the many condi-
tions that indicate the use of a mechanical return system.
Any use of a receiver and pump must be coordinated with
the makeup water and controlled by the boiler water level
control on the boiler. This description is typical of a boiler
feed pump as opposed to a condensate pump that pumps
condensate regardless of the water level in the boiler.
4. In any steam system one of the requirements is the removal
of air from the system. A mechanical return system in most
cases has an air vent on the receiver. A gravity return sys-
tem has no receiver, so provisions for air removal must be
made on the piping itself. A one pipe system has the air
vents on the radiation, the heat exchanger and near the end
of the steam supply main (see figures 2 and 3).
Main air vents should be located fifteen inches from the drip
and if possible eight inches above the pipe so that water
hammer does not damage the vent and render the vent
inoperable.
For more information on air vents, check with any manufac-
turer of steam accessories (steam traps, boiler feed pumps,
air vents, etc.).
Attach the hood to the boiler flue outlet. Connect flue pipe full
size of hood outlet. If a vent damper is added, it must be
installed on the outlet side of the hood. See Vent Piping, on
page 4.
INSTALLATION INSTRUCTIONS FOR GXH OR GXHA LOW
PRESSURE STEAM BOILERS EQUIPPED WITH TANKLESS
OR PROVISION FOR TANKLESS AND McDONNELL &
MILLER TYPE 67 LOW WATER CUT-OFF.
STEAM CONTROLS ASSEMBLY AND INSTALLATION
INSTRUCTIONS
Steam kit components for Galaxy packaged models are packed
as follows:
A. 1. Low water cut-off control
2. Fittings
3. L.W.C.O. instruction sheet
B. 1. Pressure gauge
2. High pressure limit control
3. Water level gauge
4. Fittings
5. Instruction sheet and assembly drawing
6. Steam safety valve and 3/4" street coupling
7. Drain cock
Assemble above components exactly as shown in steam con-
trols assembly. Two 1/2" tappings are on right side of boiler for
this assembly. Two holes are pre-punched in jackets. For con-
venience, start assembling in the following steps:
1. Install 1/2" x 5-1/2" brass nipple onto tee of L.W.C.O.
2. Mount 1/2" x 5-1/2" brass nipple into lower boiler tapping by
rotating low water cut-off.
3. Assemble 90° brass tubing to tee adapter and L.W.C.O.
4. Install 1/2" x 6" brass nipple and 1/2" x 5/8" adapter tee in
upper boiler tapping.
5. Install syphon, high pressure limit and pressure gauge with
1/4" brass fittings.
6. Install water level gauge (without glass) and its fittings.
7. Install water level glass, and mark the glass 25-1/2" from the
bottom of the steel boiler base for the water level. (The
steel boiler base should not be confused with a combustible
floor kit when making the 25-1/2" measurement.)
8. Drain cock will be installed in return tee at the lower right
side of casting.
9. Safety valve and 3/4" street coupling should be installed in
3/4" tapping on top of boiler.