Fisher r 657 and 667 Diaphragm Actuators
烟花声
Fisher 657 and 667 spring-oppod diaphragm
actuators (figure 1) position the valve plug in the
valve in respon to varying controller or valve
海阳旅游positioner pneumatic output signals applied to the
actuator diaphragm. Zero tting of the actuator is
determined by the compression of the actuator
spring. Span is t by both the actuator spring rate
and the number of springs available. The 657
actuator is direct-acting; the 667 is rever-acting.
The actuators are designed to provide dependable
on-off or throttling operation of automatic control
valves.
Features
D Application Versatility—Five actuator types inppt比例
eleven sizes are available for an extensive variety of
applications. Spring rates, travel stops, and manual
operators are available for nearly any control valve
application.
D Excellent Linearity Between Loading Pressure and Travel—A molded diaphragm travels in a deep diaphragm casing, minimizing area change throughout the travel.
D High Degree of Dynamic Stability and Frequency Respon—A shallow casing on the pressure side means reduced volume on that side, thereby minimizing respon time.
D High Thrust Capability—The molded diaphragm allows maximum thrust for given diaphragm size.
D Long Service Life—Rugged thick-walled cast iron and steel construction provides incread stability, corrosion protection, and protection from deformation should over-pressurization occur.
657 ACTUATOR667 ACTUATOR W2174-2/IL
W1916-3/IL
Figure 1.Fisher 657 and 667 Actuators Mounted on
easy-e t Valves
D Cold Service Applications—Enhanced product specifications for all sizes of 657 and 667 diaphragm actuators allow performance to Ŧ50_C (Ŧ58_F). U of a positioner is recommended to ensure responsiveness in applications operating below Ŧ40_C (Ŧ40_F).
倒酒D Positive Connections—A split block stem connection provides a solid transfer of motion while allowing easy mounting. The abnce of linkages helps to avoid lost motion and inaccurate valve positioning.
2
Additional Specifications 4
...............
Volumetric Casing Displacement 5
.......
Approximate Actuator Weights
(without handwheel) 5
................
Thrust Capabilities 6
....................
Handwheel Specifications 9
.
............
Adjustable Travel Stop Styles 10
......... Dimensions 13 ..............................
Specifications 14
............................
Available Configurations
Direct Action
All 657 actuators are direct acting. Applying air pressure to the upper diaphragm casing forces the actuator stem downward. When this pressure is reduced, the opposing spring force moves the actuator stem upward. Should the loading pressure fail, the spring forces the stem to the extreme upward position. This provides fail-open action for push-down-to-clo valves and fail-clod action for push-down-to-open valves.
657—A direct-acting actuator ud on sliding-stem valves. Available in sizes 30 through 100. See figures 1, 2, 3, 6, and 7.
657-4—A 657 actuator in sizes 70 and 87, designed with 102 mm (4-inch) travel.667—A rever-acting actuator ud on sliding-stem valves. Available in sizes 30 through 100 and 76. See figures 1, 2, 3, and 8.
667-4—A 667 actuator in sizes 70 and 87, designed with 102 mm (4-inch) travel.
Accessories
Handwheels
Handwheels for diaphragm actuators are often ud as adjustable travel stops. They also provide a ready means of positioning the control valve in an emergency. The specifications in tables 5 and 6 apply to handwheels on both 657 and 667 Series actuators. For repeated or daily manual operation, the unit should be equipped with a side-mounted handwheel actuator.
Top-Mounted Handwheels—Typical 657 and 667 actuators with handwheels mounted on the diaphragm ca are shown in figure 3 (not available on a 667 actuator, size 80). On the 657 actuator,
the handwheel can be t to limit the travel in the upward direction; on the 667 actuator, travel in the downward direction can be restricted. A P-2 travel stop (figure 5) is available for a 667 actuator, sizes 45-60 to limit travel in either the upward or downward directions. An actuator with a P-2 travel stop is limited to a maximum travel of 19 mm (0.75 inch). The handwheel on the size 100 is similar in function to tho on the smaller sizes, but it us a gear drive similar to the drive employed on the integral side-mounted handwheels (e figure 3).
3
W0364-2/IL
W0363-2/IL
667 SIZES 30-87657 SIZES 30-87
W0366-1/IL
千佛山门票
657 SIZE 100
谁喜欢卷帘大将
YOKE
Figure 2. Typical Actuators
4
5
Table 3. Approximate Actuator Weights (without handwheel)
ACTUATOR
SIZE
ACTUATOR
657
667
657
guesd667
Kg Lb
301615363434222248484023235150453741829046495510712150424392946053551161227010711523525476- - -86- - -1908023428451562687116118255260100
346
544
762茶具名称
1200
