Data Sheet

Bulletin 71.2:310A
6
Installation
The Type 310A may be installed in any position, but is
normally installed in a horizontal pipeline with the pilot
or pilots above the body. See Figures 6, 7, and 8 for
typical piping installation.
Capacity Information
Note
Type 310A regulator flow capacities
are laboratory verified; therefore, they
may be sized for 100% flow using
capacities as shown in Tables 8, 9,
10, 11, and 12. It is not necessary to
reduce published capacities.
Tables 8, 9, 10, 11, and 12 show the natural gas
regulating capacities of the Type 310A regulator at
selected inlet pressures and outlet pressure settings.
Flows are in thousands of SCFH at 60°F and 14.7 psia
(and in thousands of Nm
3
/h at 0°C and 1,01325 bar) of
0.6 specific gravity natural gas.
To determine equivalent capacities for air, propane,
butane, or nitrogen, multiply the capacity by the
following appropriate conversion factor: 0.775 for
air, 0.628 for propane, 0.548 for butane, or 0.789
for nitrogen. For gases of other specific gravities,
multiply the given capacity by 0.775, and divide by the
square root of the appropriate specific gravity. Then,
if capacity is desired in normal cubic meters per hour
at 0°C and 1,01325 bar, multiply SCFH by 0.0268.
To find approximate regulating capacities at pressure
settings not given in Tables 8, 9, 10, 11, and 12 or
to find wide-open ow capacities for relief sizing
at any inlet pressure, perform one of the following
procedures. Then, if necessary, convert using the
factors provided above.
For critical pressure drops (absolute outlet pressure
equal to or less than one-half of absolute inlet
pressure), use the following formula:
Q = (P
1
)(C
g
)(1.29)
For pressure drops lower than critical (absolute
outlet pressure greater than one-half of absolute
inlet pressure).
Q = C
g
P
1
SIN DEG
520 3417
P
GT C
1
P
1
where,
Q = gas ow rate, SCFH
P
1
= absolute inlet pressure, psia
(P
1
gauge + 14.7)
C
g
= regulating or wide-open gas sizing
coefficient from Table 4, 5, or 6
G = gas specific gravity of the gas
T = absolute temperature of gas at inlet, °Rankine
C
1
= ow coefficient
P = pressure drop across the regulator, psi
Figure 6. Typical Pressure Reducing Installation
24B4134
B2444
LOADING TUBING
HAND VALVE
1/4-INCH NPT PILOT
SUPPLY CONNECTION
VENT VALVE
BLOCK VALVE
BYPASS VALVE
BYPASS LINE
VENT VALVE
1/2-INCH (13 mm)
DOWNSTREAM CONTROL LINE
HAND VALVE
LOCATE 6 TO 10 PIPE
DIAMETERS FROM
VALVE OUTLET
VENT VALVE
BLOCK VALVE
ALTERNATE
DOWNSTREAM
CONTROL LINE TAP