Page 6
LAARS HEATING SYSTEMS
Length
Capacity of Pipe in MBTU/h
of
(.6 Specific Gravity)
Pipe
3/4"
1"
1-1/4"
10'
278
520
1,050
20'
190
350
730
30'
152
285
590
40'
130
245
500
50'
115
215
440
75'
93
175
360
100'
79
150
305
150'
64
120
250
Additional length to be added for each tee or bend:
1.7'
2.2'
2.7'
bronze circulating pump is built into the appliance.
The pump draws water from the storage tank and
pumps the water through the heater and back into
the tank.
Position the storage tank(s).
At the previously selected locations, position the
storage tank(s). Use Table 3 to determine the pipe size
necessary to provide adequate flow between the 9600
HWG and the tank(s).
Hot water outlet piping, fittings, and accessories.
1.
Begin piping to the tank from the hot water
outlet at the top of the 9600 HWG cabinet.
2.
Pipe the outlet from the relief valve (located on
top of the unit) such that any discharge from the
relief valve will be conducted to a suitable place
for disposal when relief occurs. Do not reduce
line size or install any valves in this line. The
line must be installed to allow complete drainage
of both the valve and the line.
3.
Install a shut off valve in the piping between the
thermometer fitting and the tank.
Cold water supply piping, fittings and accessories.
1.
Install a strainer between the 9600 HWG and the
system. For proper pipe size and distance
limitations, refer to Table 3.
2.
Connect a drain valve and a shut off valve to the
9600 HWG cold inlet. On multiple units install a
check valve at each units cold water inlet.
3.
Where check valves have been installed on cold
water inlet piping, check to be sure system has
an adequately sized expansion tank to allow
thermal expansion to occur.
Hot water supply piping.
Follow the manufacturers guidelines for
completion of the hot water system connections.
3B. Connecting Gas to the 9600 HWG
Water Heater
1.
The water heater requires gas at an inlet gas
pressure of at least 4" WC and no greater than
13" WC. Check with your local gas utility or
supplier for availability of these delivery
pressures.
2.
Referring to TABLE 2, size supply piping to
keep flow capacity to the unit above 250 cubic
feet per hour (CFH) per unit installed.
3.
Run gas supply line in accordance with all
applicable codes.
4.
Locate and install manual shutoff valves in
accordance with state and local requirements.
5.
Install drip leg and ground joint union
(see Figure 5).
6.
All threaded joints should be coated with piping
compound resistant to action of liquefied
petroleum gas.
7.
The 9600 HWG unit and its individual shutoff
valve must be disconnected from the gas supply
piping during any pressure testing of that system
at test pressures in excess of 1/2 psig (3.45kpa).
It must be isolated from the gas supply system by
closing its individual manual shutoff valve
during any pressure testing of the gas supply
piping system at test pressures equal to or less
than 1/2 PSIG (3.45kpa).
Failure to do so will possibly result in damage to
the gas control system.
8.
The 9600 HWG Water Heater and its gas
connections must be leak tested before placing
the unit in operation.
9.
Purge all air from gas lines.
Figure 5. Gas supply piping.
Table 2. Gas supply piping.
To
9600 HWG
3C. Connecting Water System Piping,
Fittings & Accessories
Installing tank & piping
The 9600 HWG can be used with several
different types of readily available storage tanks. A
Manual Main
Shut Off
Gas Supply
Drip Leg
Cap
