Emerson Fisher 377 Instruction Manual page 5

Instruction Manual
D200319X012
CAUTION
Do not use sealing tape on pneumatic connections. This instrument contains small passages that may become obstructed
by detached sealing tape. Thread sealant paste should be used to seal and lubricate pneumatic threaded connections.
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
leakage. Therefore, using control system accessories, such as volume boosters, between the trip valve and the actuator is
not recommended. If this cannot be avoided and a volume booster is required, a volume booster designed for tight shutoff,
such as the Fisher 2625, provides a higher probability of control system integrity. Refer to figures 5 and 6 for proper
installation of 377 trip valves with 2625 volume boosters.
Figure 5. Fisher 2625 Volume Booster used with 377U or 377D Trip Valve
2625
3/4 NPT OR
1/2 NPT PIPING
PISTON
ACTUATOR
POSITIONER
3/4 NPT
CHECK VALVE
3/4 NPT OR
1/2 NPT PIPING
NOTES:
1 THE HOOK UP OF PORT C AND F ARE REVERSED FOR 377D.
2. 3/4 NPT CHECK VALVE, 1/2 OR 3/4 NPT PIPING, AND 1/2‐INCH (OUTSIDE DIAMETER) COIL TUBING FOR THE VOLUME TANK ARE REQUIRED.
3. THE SUPPLY PRESSURE REGULATOR SPECIFIED MUST HAVE ADEQUATE CAPACITY FOR 2625 BOOSTERS. ALSO, IF THE 2625 BOOSTER IS TO BE NIPPLE MOUNTED, THE BOOSTER MUST BE
MOUNTED TO A 1/2 NPT OR LARGER CYLINDER CONNECTION. SOME SMALLER CYLINDERS CANNOT BE TAPPED THIS LARGE; CONTACT YOUR
SPECIFIC TYPES AND SIZES.
E1570
1/2 O.D. TUBING
1/2 O.D. COIL VOLUME
TANK TUBING
VENT
SUPPLY
INPUT SIGNAL
FISHER i2P-100/
67CFR
377U 1
EMERSON SALES OFFICE
377 Trip Valve
June 2017
3/8 O.D.
TUBING
TYPICAL
VOLUME
TANK
FOR AVAILABILITY ON
5