Data Sheet
Bulletin 71.7:168
3
Inoperation,increasingdiaphragmpressurefroma
controller or other source moves the stem and upper
adjusting nut toward the trip lever (see Figure 2). When
the diaphragm pressure reaches the predetermined
upper switching point, the upper adjusting nut pivots the
trip lever to move the rocker assembly to its alternate
position, closing port C and opening port B.
When decreasing diaphragm pressure reaches the
lower tripping pressure, the lower adjusting nut returns
the rocker to its original position.
Installation
Type 68-2 switching valves may be installed in
any position.
Types 168 and 168H switching valves should be
positioned so that moisture cannot enter either the
vent or the small hole in the end of the stem protector.
Pipe the common pressure line to connection A (the
connection located in the end of the body portion).
Dimensions are shown in Figures 3 and 4.
Type 68-2
When ordering, specify:
1. Type number
2. Maximum inlet pressure to body
Types 168 and 168H
When ordering, specify:
1. Type number
2. Diaphragm pressure range
3. Upper and lower tripping pressures
4. Maximum inlet pressure to body
5. Optional mounting bracket, manual reset switch,
orcontrolvalveyokemountingpartsifdesired.If
control valve yoke mounting parts are ordered,
specify actuator type and size.
B
W0110-2
Figure 2. Type 168 Operational Schematic
Figure 3. Type 68-2 Switching Valve Dimensions
AU9155-B
1.75
(44)
5.41
(68)
(25)
B
A
2.00
(51)
1.00
(25)
0.45
(11)
0.45
(11)
1.00
(25)
(4,8)
(mm)
A