Installation | High Pressure Gas Regulator
INSTALLATION The North American 7347 Regulator may be installed in any orientation as long as flow through it matches the direction arrow cast on the body. Normal installation is with the spring case vertical above or below the diaphragm case. If gas escaping through the internal relief could constitute a hazard the spring case vent must be piped to a location where escaping gas will not be hazardous. If the vented gas will be piped to another location use obstruction-free tubing or piping at least equal in size to the vent. The end of the vent pipe must be protected from anything that might clog it. OVERPRESSURE PROTECTION Like most pressure-reducing regulators, the 7347 Regulators have outlet pressure ratings that are lower than the inlet pressure ratings. Therefore, a pressure relieving or pressure limiting device is needed if the inlet pressure can exceed the outlet pressure rating, see "Specifications". The internal relief in this regulator does provide limited downstream overpressure protection, but it should not be considered complete overpressure protection. Refer to the capacity information section to determine the required relief valve capacity.
CAPACITY INFORMATION Table C provides the natural gas regulating capacities of the 7347 regulators at specific inlet pressures and outlet pressure settings. Flows are in SCFH (60°F and 14.7 psia) of 0.6 specific gravity gas. For specific gravity conversion factors to other gases, refer to the selection section.
To determine the wide-open flow capacity of a regulator for relief sizing, use the following formula.
97.63 (
)
√
P P [ as degrees]
√ 520 GT
Q =
110 P sin
G P Q
= gas specific gravity (air = 1.0)
= inlet pressure, psia = flow rate, SCFH
T
= absolute temperature of gas at inlet in ºRankine = differential pressure, psi (The difference between the regulator inlet pressure and the maximum outlet pressure that can be tolerated by downstream components)
P
Table B. 7347 Regulator Springs
10-24"w.c. (25-60 mbar) 10-26"w.c. (25-65 mbar) 0.5-2 psig (0.03-0.14 bar) 10-24"w.c. (25-60 mbar) 10-26"w.c. (25-65 mbar) 0.5-2 psig (0.03-0.14 bar) 10-24"w.c. (25-60 mbar) 10-26"w.c. (25-65 mbar) 0.2-2 psig (0.03-0.14 bar) Approx. point above pressure setting @ which internal relief starts to discharge
Max. inlet pressure psig
Droop *
Outlet Pressure Range Compression Spring Color Number
End Connections
7347-0-G 7347-0-A 7347-0-B‡ 7347-1-G 7347-1-A 7347-1-B‡ 7347-2-G 7347-2-A 7347-2-B‡ Regulator Designation
4-8"w.c. (10-20 mbar) 15-33"w.c. (37-83 mbar)
Red
R690-5278 R690-5279 R690-5280 R690-5278 R690-5279 R690-5280
1"w.c. (2.5 mbar) 5.5"w.c. (14 mbar) 5.5"w.c. (14 mbar) 1"w.c. (2.5 mbar) 5.5"w.c. (14 mbar) 5.5"w.c. (14 mbar) 1"w.c. (2.5 mbar) 1"w.c. (2.5 mbar) 5.5"w.c. (14 mbar)
35 35 60 35 35 60 35 35 60
¾ " NPT
Yellow
1.2-2.5 psig (0.08-0.17 bar) Green
4-8"w.c. (10-20 mbar) 15-33"w.c. (37-83 mbar)
Red
1" NPT
Yellow
1.2-2.5 psig (0.08-0.17 bar) Green
4-8"w.c. (10-20 mbar) 7-16"w.c. (17-40 mbar)
Red
R690-5278
1¼" NPT
Unpainted R690-5270
1.2-2.5 psig (0.08-0.17 bar) Green
R690-5280
‡ Within a grouping, by changing compression springs, the "B" regulator may be made into either of two regulators above it; and those two above may be changed into each other, but they cannot be changed into "B" regulators because they lack the high pressure diaphragm head assembly. * Droop is the difference between outlet pressure selected and that realized when operating at capacities listed in this table.
Bulletin 7347 Page 3
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