Data Sheet

Bulletin 71.1:133
7
Forrestricted-capacityconstructions,determineow
capacities for outlet pressure settings of 2 psig /
0.14 bar or less by multiplying the values from
Tables 3 to 10 by 25%, 40%, or 60% (depending upon
which restriction collar is selected). For pressure
settings over 2 psig / 0.14 bar, capacities are given
inTable6.Ifowcapacitiesforinletpressures
lower than those shown are required, contact your
localSalesOfce.Therepresentativeregulating
C
g
of 1650 may be used for regulator sizing of full
capacity constructions only if capacity table data is
not available. The representative regulating C
g
is an
approximation only for pressure drops greater than
5 psi / 0.34 bar, because, at a given offset in controlled
pressure, the regulating C
g
varies with the spring being
used with the pressure drop across the valve.
TodeterminecapacityusingtheowcoefcientC
g
,
use the appropriate procedure below.
Critical Pressure Drops
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)
Non-Critical Pressure Drops
For pressure drops lower than critical (absolute outlet
pressure greater than one-half of absolute
inlet pressure).
Q = C
g
P
1
SIN
520
GT
3417
C
1
∆P
P
1
DEG
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coefcient
   G =specicgravityofthegas
T = absolute temperature of gas at inlet, °Rankine
C
1
 =owcoefcient
P = pressure drop across the regulator, psi
W1032-1/IL
TWO-WAY STABILIZER VENT VALVE IN “UP” POSITION
AS DIAPHRAGM RISES
Figure 5. Types 133H, 133L, and 133Z Stabilizer Vent
VENT VALVE IN “DOWN” POSITION
AS DIAPHRAGM LOWERS
W1902-1/IL
Table 3. Full-Capacity Type 133Z Regulated Flow in Thousands of SCFH of 0.6 Speci c Gravity Gas at 14.7 psia and 60°F
INLET PRESSURE
1 inch w.c. / 3 mbar OUTLET PRESSURE SETTING
(1)
(EITHER SPRING RANGE)
0.5 inch w.c. / 1 mbar Droop 1 inch w.c. / 3 mbar Droop
psig bar SCFH Nm
3
/h SCFH Nm
3
/h
8 inches w.c.
14 inches w.c.
1
2
20 mbar
35 mbar
0.07
0.14
2.4
4.1
6.5
11.5
0.06
0.11
0.17
0.31
5.1
7.4
12
18
0.14
0.20
0.32
0.48
5
10
20
0.34
0.69
1.4
22
44
76
0.59
1.18
2.04
32
50
78
0.86
1.34
2.09
1. Outlet pressure setting was made at approximately 10% of the maximum capacity for the listed conditions.