Instruction Manual
D103292X012
C1 Controllers and Transmitters
March 2017
10
Supply pressure medium must be clean, dry, and noncorrosive and meet the requirements of ISA Standard 7.0.01 or
ISO 8573-1. A maximum 40 micrometer particle size in the air system is acceptable. Further filtration down to 5
micrometer particle size is recommended. Lubricant content is not to exceed 1 ppm weight (w/w) or volume (v/v)
basis. Condensation in the supply medium should be minimized.
Use a suitable supply pressure regulator to reduce the supply pressure source to the normal operating supply pressure
shown in table 5. Connect supply pressure to the SUPPLY connection at the back of the case.
WARNING
To avoid personal injury or property damage resulting from the sudden release of process pressure, use a high pressure
regulator system when operating the controller or transmitter from a high pressure source.
If operating the controller or transmitter from a high pressure source [up to 138 bar (2000 psig)], use a high pressure
regulator system, such as the Fisher 1367 High Pressure Instrument Supply System. For 1367 system installation,
adjustment, and maintenance information, refer to the 1367 High-Pressure Instrument Supply System with
Overpressure Protection instruction manual,
Process Pressure
WARNING
To avoid personal injury or property damage resulting from the sudden release of pressure when using corrosive media,
make sure the tubing and instrument components that contact the corrosive medium are of suitable noncorrosive
material.
Also refer to the Installation Warning at the beginning of this section.
The pressure connections to the controller depend upon the type of pressure sensing, gauge or differential. Gauge
pressure controllers use either a Bourdon tube or bellows as the sensing element, as indicated in table 2. Differential
pressure controllers use two bellows to sense differential pressure.
For gauge pressure instruments:
The control pressure block (key 10 in figure 22) has two connections. Process
pressure can be connected either to the CONTROL connection on the back of the case, or to the connection on the left
side of the case, shown in figure 2, depending on the instrument application. Plug the unused connection.
For differential pressure instruments:
Connect the low pressure line to the CONTROL connection on the side of the
When installing process piping, follow accepted practices to ensure accurate transmission of the process pressure to
the controller or transmitter. Install shutoff valves, vents, drains, or seal systems as needed in the process pressure
lines. If the instrument is located such that the adjacent process pressure lines will be approximately horizontal, the
lines should slope downward to the instrument for liquid-filled lines and upward to instruments for gas-filled lines. This
will minimize the possibility of air becoming trapped in the sensor with liquid-filled lines or of condensation becoming
trapped with gas-filled lines. The recommended slope is 83 mm per meter (1 inch per foot).
If a controller is being used in conjunction with a control valve to control pipeline pressure, connect the process
pressure line in a straight section of pipe approximately 10 pipe diameters from the valve but away from bends,
elbows, and areas of abnormal fluid velocities. For pressure-reducing service, the process line must be connected
downstream of the valve. For pressure-relief service, the process pressure line must be connected upstream of the
control valve. Install a needle valve in the process pressure line to dampen pulsations.
