Instruction Manual
D200319X012
377 Trip Valve
August 2012
4
Figure 4. Maximum Trip Point Settings
10.3
4
5
6
7
8
9
10
110
100
90
80
70
60
50
40
7.6
7
6
5
4
3
150
140
130
120
110
100
90
80
70
60
55
NOTES:
TRIP POINT MAY BE SET TO ANY VALUE BETWEEN 2.8 BAR (40 PSIG) AND THE MAXIMUM TRIP POINT LINE.
RESET OCCURS AT 12.5 TO 33 PERCENT ABOVE ADJUSTED TRIP POINT.
TRIP POINT, PSIG
TRIP POINT, BAR
SUPPLY PRESSURE, BAR
SUPPLY PRESSURE, PSIG
A2779‐2/IL
MAXIMUM TRIP POINT
SETTING TO ENSURE
RESET
1
2
2
1
Installation
WARNING
Avoid personal injury from sudden release of process pressure. Before mounting the controller:
D
Always wear protective clothing, gloves, and eyewear when performing any installation operations to avoid personal
injury.
D
Overpressuring any system component could result in personal injury or property damage due to fire and explosion
caused by venting or leakage of the supply medium. To avoid such injury or damage, provide suitable pressure‐relief or
pressure‐limiting devices if the supply pressure is capable of exceeding the maximum allowable pressure of the system
component.
D
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
D
If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.
The 377 trip valve is normally ordered as part of a control valve assembly. Follow the procedure in the appropriate
valve body and actuator instruction manual when installing the control valve in the piping.
If the 377 trip valve is shipped separately from the control valve assembly, the installation procedure depends upon
the type of actuator and accessory equipment required for the individual control valve system. Install any accessory
equipment in the control valve system so that the overall functioning of the specified trip valve pressure line
connections is not disrupted. Figures 7, 8, and 9 are schematics showing the pressure line connections for each of the
three possible fail‐mode configurations of the trip valve.
CAUTION
377 trip valves are leak tested to ensure that the intended actuator fail mode is maintained upon loss of supply pressure.
Control system accessories, such as volume boosters with hard seats, compromise the integrity of the entire system due to
