Instruction Manual
D200319X012
377 Trip Valve
August 2012
5
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
1/2 O.D. TUBING
PISTON
ACTUATOR
POSITIONER
3/4 NPT
CHECK VALVE
3/4 NPT OR
1/2 NPT PIPING
SUPPLY
377U
FISHER
i2P-100/67CFR
3/8 O.D.
TUBING
TYPICAL
1
1
NOTES:
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 EMERSON PROCESS MANAGEMENT SALES OFFICE
FOR AVAILABILITY ON SPECIFIC TYPES AND SIZES.
3/4 NPT OR
1/2 NPT PIPING
21B3154‐C
1/2 O.D. COIL VOLUME TANK TUBING
VOLUME
TANK
VENT
Supply Pressure Requirements
WARNING
Severe personal injury or property damage may occur if the instrument air supply is not clean, dry, and oil free. While use
and regular maintenance of of a filter that removes particles larger than 40 micrometers in diameter will suffice in most
applications, check with an Emerson Process Management field office and instrument industry air quality standards for use
with corrosive gas or if you are unsure about the proper amount or method of air filtration or filter maintenance.
A supply regulator, if used, must have a flow capacity greater than the required combined capacity of the trip valve and
actuator. In order to ensure proper selection of a supply regulator, be sure the C
v
value of the regulator is greater than
