Midco Unipower MPG Series - Manual (Page 7)

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Piping must comply with national and local codes.
Provide a sediment trap, manual safety shut-off valve and union in piping close to burner as
shown in Figure 8:
To obtain the maximum firing rate of the burner, the fuel gas supply piping must be sized to
provide a minimum of 5" w.c. pressure to the inlet of the combination valve when the burner and
all other gas appliances are on based on valve train size.
For the usual low pressure gas supply system, 5" to 14" W.C. NATURAL (11" to 14" W.C.
PROPANE) use Table 5 to find the recommended gas supply line size.
Piping follows normal practices and should be connected to the burner in the manner shown
in Figure 8. If the piping must be rearranged because of space limitations be sure to carry out the
sequence of components illustrated. While the pilot regulator can be mounted in any position, the
main regulator should be mounted upright and in a horizontal run of pipe.
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 the necessary burner gas inlet pressure.
CAUTION: High gas pressure supply lines require the proper pressure reducing
regulators. Install two separate high pressure regulators, of the Tight Shut-Off type
upstream of the low pressure regulators. One sized for main gas input, and one suitable
for the minimum flow regulating capacity of the pilot.
The high pressure regulators may be substituted for the low pressure regulators. If high pressure
regulators are used as substitutes, they must be adjustable down to a minimum of 2"
W.C. outlet pressure for the pilot and 5" W.C. for the main gas. They must be adjustable down to the
maximum burner inlet pressure rating (14" W.C.).
DANGER: Explosion hazard.
Do not use oxygen for pressure testing. An
explosion could occur during initial start-up.
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 or other liquids to locate
leaks.
CAUTION: Because it is difficult to accurately control pressure, disconnect all low
pressure (14" W.C. max.) components (main and pilot) during supply pipe leak testing.
Exposing low pressure regulators and valves to a pressure over 1/2 PSIG (14" W.C.) will
damage components and void their warranties.
Part 1 Installation
VI Piping
Figure 8: Standard Piping Diagram MPG Burner
Pilot components and manual valves are shipped loose