Midco Economite RE4400B / RE4400BA - Manual (Page 6)

6
CAUTION: The available gas pressure should be within the limits shown in
SPECIFICATIONS section. Excessive pressure may damage electric valves, regulators
and manual valves. If the supply pressure exceeds the 14.0"W.C. maximum, a suitable
high pressure regulator must be installed between the Main Manual Shut-Off Valve and
burner shut-off valve as shown in Figure 5.
The burner gas supply piping should branch off from the main line as close to the gas
meter as possible. Do not connect to the bottom of a horizontal section. Use new black pipe
and malleable fittings free of cutting and threading burrs or defects.
Provide a sediment trap, union and 1/8" pressure tap in piping close to burner as shown
in Figure 5.
Use pipe joint compound approved for use with Liquid Petroleum Gases.
Piping must also comply with your local codes.
To obtain the maximum firing rate of the burner, the gas supply piping must be sized to
provide a minimum of 7.0"W.C. pressure to the inlet of the upstream automatic safety shut-
off valve when the burner and all other gas utilization equipment are on. The pilot regulator
can be mounted in any position, the main regulator, if equipped, should be mounted upright
and in a horizontal run of pipe.
CAUTION: Because it is difficult to accurately control pressure during supply
pipe leak testing, it is recommended that all low pressure (14.0"W.C. max.)
components, both main and pilot, be disconnected during testing. Exposing low
pressure regulators and valves, including manual valves, to pressures over 1/2 PSIG
(14.0"W.C.) will cause damage and void all warranties.
DANGER: Explosion hazard.
Do not use oxygen for pressure testing.
An explosion could occur during initial start up.
If the burner piping must be rearranged because of space limitation, be sure to carry out
the general arrangement shown in Figure 5. Install the combination valve (RE4700BA,
RE4400B & RE4400BA only ) in any position except up-side down.
When the burner is installed in the vestibule of jacketed equipment, it is recommended
that the Automatic Safety Shut-Off Valves be left adjacent to the burner within the vestibule
and the Main Manual Shut-Off Valve be installed outside.
Run full size pipe or tubing from regulator vent openings to outside of building. Provide no
traps in the vent lines and terminate away from all doors and windows; also make provisions
for keeping rain and foreign objects from entering the vent piping.
When high supply gas pressure is encountered, as in the case in many industrial plants,
the gas line size can be reduced to allow for a greater pressure drop; however, the size must
be sufficient to deliver burner rating pressure.
CAUTION: High gas pressure supply lines require the proper pressure
reducing regulators. Install a high pressure regulator of the Tight Shut-Off type
upstream of the low pressure regulator. Sized for main gas input, and suitable for
the minimum flow regulating capacity of the pilot.
The high pressure regulator must be adjustable to 14" W.C. outlet pressure.
When the gas supply line is about to be put into service it must be tested to insure that it
is gas tight. Use air or inert gas under pressure and test with soap and water to locate leaks.
Before gas is turned onto the system, a check must be made to see that there are no open
fittings and to make sure the burner main and pilot manual valves are closed.
After checking for leaks, purge the gas line up to the burner inlet. Purging the air from the
gas supply line at this step will expedite the first light-off.
NOTE: If there is more than 1.0" W.C. differential in the inlet pressure to the burner
compared to when all other gas utilization equipment are off, refer to Section VI.
Part 1
Installation
Continued
Part 1 Installation
Capacities shown are for a
total pressure drop of
0.3"W.C. For 0.5"W.C.
pressure drop, multiply
capacity shown by 1.3 .
Propane capacities shown
are for a total pressure drop
of 0.5” W.C. For higher
permissible pressure drops,
consult your gas supplier.
Table 2: Schedule 40 NPT
Pipe-Capacity Chart
10
200
590
400
1075
900
40
275
200
500
450
1040
650
75
190
150
360
325
750
475
20
150
400
275
730
600
900
Pipe
Size
3/4
3/4
1
1
1 1/4
1 1/4
1 1/2
1 1/2
Natural
Propane
Natural
Propane
Natural
Propane
Natural
Propane
100
160
300
275
630
400
975
Approximate Capacity -MBH
Pipe Length
Type
of Gas
VI Piping