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AIR LIFTS
STEM UP
A6759/IL
Figure 2. Schematic of Type 667 and 667-4 Actua-
If repeated or daily manual operation is
expected, the actuator should be
equipped with a side-mounted hand-
wheel rather than a casing-mounted
travel stop or top-mounted handwheel.
The side-mounted handwheel is de-
signed for more frequent use as a manu-
al operator.
Specifications
Refer to table 1 for Specifications of the Type 667 and
667-4 actuators. See the actuator nameplate for spe-
cific information for your actuator.
CAUTION
To avoid damage to equipment that may
result in the malfunction of the control
valve or loss of control of the process
caused by excessive pressure, do not
exceed the Maximum Pressures listed in
table 1. Refer to the Maximum Pressure
Limitations section below.
Maximum Pressure Limitations
The casing and diaphragm of Type 667 actuators are
pressure operated. This air pressure provides energy
to compress the spring, to stroke the actuator, and to
seat the valve. The following explanations describe the
SPRING PUSHES
STEM DOWN
STEM
SEAL
STEM
tors
Note
Type 667 Size 30-76 & 87
maximum pressure limits for an actuator. Refer to the
nameplate or table 1 for maximum values for your ac-
tuator.
D Maximum Casing Pressure for Actuator Siz-
ing: This is the maximum pressure that can be applied
at less than full travel of the actuator. If this stroking
pressure is exceeded before the upper diaphragm
plate contacts the travel stop, damage to the stem or
other parts might result.
D Maximum Excess Diaphragm Pressure: Addi-
tional pressure may be added when the actuator is at
full travel. If the Maximum Excess Diaphragm Pres-
sure is exceeded, damage to the diaphragm or dia-
phragm casing might result.
Because the actuator has traveled its specified travel,
and the diaphragm head is physically stopped from
movement, the energy from any additional air pressure
is transmitted to the diaphragm and diaphragm cas-
ings. The amount of air pressure that can be added
once the actuator has traveled to the stops is limited
by the resultant adverse effects that may occur. Ex-
ceeding this limiting factor could result in leakage or
casing fatigue due to the deformation of the upper dia-
phragm casing.
D Maximum Diaphragm Casing Pressure: If the
Maximum Diaphragm Casing Pressure is exceeded,
damage to the diaphragm, diaphragm casing, or ac-
tuator might result.
Installation
Key number locations are shown in figures 6, 7, and 8,
unless otherwise noted. Also, refer to figure 3 for loca-
tion of parts.
CAUTION
To avoid damage to equipment, do not
exceed any of the maximum Diaphragm
Pressures listed in table 1.
D Valve/Actuator Assembly: If the actuator and
valve are shipped together as a control valve assem-
bly, it has been adjusted at the factory, and may be
installed in the pipeline. After installing the valve in the
pipeline, refer to the Loading Connection procedures.
D Actuator Mounting: If the actuator is shipped
separately or the actuator has been removed from the
valve, it is necessary to mount the actuator on the
valve before placing the valve in the pipeline. Refer to
the following actuator mounting procedures before
placing the valve in service. It is recommended that
3
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