Data Sheet

YD and YS Valves
D100031X012
Product Bulletin
51.1:YD
June 2014
20
Table 8. Maximum Allowable Fisher YS (Diverging Service) Shutoff Pressure Drops with 657 and 667 Actuators
(ON-OFF) application only–No throttling service
(1)
(continued)
PACKING TYPE ACTUATOR SIZE
NOMINAL (ACTUAL) AIR TO DIAPHRAGM, PSIG
(2)
3-15 (0-18) 6-30 (0-33) 3-40 (0-43)
nP
(6)
, PSID/(Bench Set, PSIG)
(7)
/Spring Drawing Number
NPS 6, 7-Inch Port, Cl ass IV Seat Leakage
(5)
Standard
Single or
Double PTFE
50 --- ---
50
(11-31)
1E8272
60 ---
45
(7.5-21)
1E8272
---
70
35
(5-13)
1N1286
75
(6-26)
1N7193
---
ENVIRO-SEAL PTFE
50 --- ---
45
(11-31)
1E8272
60 ---
40
(7.5-21)
1E8272
---
70
30
(5-13)
1N1286
70
(6-26)
1N7193
---
ENVIRO-SEAL
Graphite ULF
76
(667 Only)
--- ---
50
(13-29)
1N1284
70 ---
50
(10-22)
1N1284
---
Graphite Ribbon/
Filament (CL300)
76
(667 Only)
---
45
(11-22)
(3)
1N1286
---
70 ---
70
(6-26)
1N7193
---
1. Spring and bench sets selected for use with either 657 or 667. Other acceptable configurations possible from Fisher Specification Manager for a specific actuator type
2. The bench set values shown assume an actual supply pressure to the actuator of 0 to 18 psig for a nominal 3 to 15 psig signal, an actual 0 to 33 psig supply for a nominal 6 to 30 psig signal,
and an actual 0 to 43 psig supply for a nominal 3 to 40 psig signal. Any positioner or controller used with these actuators must be capable of delivering the appropriate slightly extended range.
3. Requires non-standard spring adjustor.
4. Oversize yoke boss required.
5. Special Class 4 seat load (40 lb/lineal inch) used for YS, 7-inch port.
6. Assumes same shutoff pressure drop for top and bottom ports.
7. Bench sets selected will provide sufficient seat loading, even with no pressure drop. The selected bench sets will enable the actuator to fully stroke the valve up or down with the maximum
shutoff drop listed.