Data Sheet

Bulletin 71.1:67D
6
Note
The 67D Series regulators may be sized for 100%
ow using capacities as shown in Table 4. It is
not necessary to reduce published capacities.
To determine the equivalent capacities for other gases,
multiply the table capacity by the following appropriate
conversion factor: 1.29 for 0.6 specic gravity natural gas,
0.810 for propane, 0.707 for butane, or 1.018 for nitrogen.
For gases of other specic gravities, divide the table
capacities by the square root of the appropriate specic
gravity. To nd 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
)
For pressure drops lower than critical (absolute outlet
pressure greater than one-half of absolute inlet pressure),
use the following formula:
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
= gas sizing coefcient
G = specic gravity of the gas
T = absolute temperature of gas at inlet, °Rankine
C
1
= ow coefcient (C
g
÷ C
v
)
P = pressure drop across the regulator, psi
Then, if capacity is desired in normal cubic meters per hour
(at 0°C and 1.01325 bar), multiply SCFH by 0.0268.
NACE Universal Compliance
Optional materials are available for applications handling sour
gases. These constructions comply with the recommendations
of NACE International sour service standards.
The manufacturing processes and materials used by
Regulator Technologies assure that all products specied
for sour gas service comply with the chemical, physical, and
metallurgical requirements of NACE MR0175 and/or NACE
MR0103. Customers have the responsibility to specify
correct materials. Environmental limitations may apply and
shall be determined by the user.
Overpressure Protection
The 67D Series regulators have maximum outlet pressure
ratings that are lower than their maximum inlet pressure
ratings. A pressure-relieving or pressure-limiting device is
needed if inlet pressure can exceed the maximum outlet
pressure rating.
Types 67DR, 67DSR, 67DFR, and 67DFSR regulators have
a low capacity internal relief valve for minor seat leakage only.
Other overpressure protection must be provided if the maximum
inlet pressure can exceed the maximum pressure rating of the
downstream equipment or exceeds maximum outlet pressure
rating of the Type 67DR, 67DSR, 67DFR, or 67DFSR regulator.
Overpressuring any portion of a regulator or associated
equipment may cause leakage, parts damage, or personal
injury due to bursting of pressure-containing parts or
explosion of accumulated gas. Regulator operation within
ratings does not preclude the possibility of damage from
external sources or from debris in the pipeline. A regulator
should be inspected for damage periodically and after any
overpressure condition.
Refer to the Capacity Information section and the Wide-
Open Flow Coefcients for Relief Valve Sizing in the
Specications section on page 3 to determine the required
relief valve capacity.
Capacity Information
Table 4 shows the air regulating capacities of the
67D Series regulators at selected inlet pressures and
outlet pressure settings. Flows are shown in SCFH (at
60°F and 14.7 psia) and in Nm
3
/h (at 0°C and 1.01325 bar)
of air.
Figure 3. 67D Series Vent Positions
GE31784
POSITION 1 (ALIGNED WITH INLET) (STANDARD)
POSITION 3
POSITION 2POSITION 4