Supply Pressure; Process Pressure; Output Pressure - Fisher 4660 Instruction Manual

Type 4660
18A3804-F
A3299-1 / IL
18A3804-G/DOC
Figure 4. Location of Pressure Connections

Supply Pressure

WARNING
Personal injury or property damage may
occur from an uncontrolled process if
the supply medium is not clean, dry, oil-
free air, or a non-corrosive gas. Industry
instrument air quality standards de-
scribe acceptable dirt, oil, and moisture
content. Due to the variability in nature
of the problems these influences can
have on pneumatic equipment, Fisher
Controls has no technical basis to rec-
ommend the level of filtration equipment
required to prevent performance degra-
dation of pneumatic equipment. A filter
or filter regulator capable of removing
particles 40 microns in diameter should
suffice for most applications. Use of
6
Figure 3. Cutout Dimensions for Panel Mounting
Supply pressure must be clean, dry air or non-corro-
sive gas that meets the requirements of ISA Standard
S7.3-1975 (R1981). Use a suitable filter regulator,
such as the Type 67CFR regulator to remove solid
particles and to maintain the supply pressure source
within the normal operating range of 20 to 35 psig (1.4
to 2.4 bar). Refer to table 1 for the pilot supply flow
requirement (relay construction only). As shown in fig-
ure 4, connect supply pressure to the connection
marked SUPPLY on the bottom of the pilot case.

Process Pressure

Connect process pressure to the connection marked
PROCESS on the bottom of the pilot case as shown in
figure 4. When installing process pressure piping, fol-
low accepted practices to ensure accurate transmis-
sion of the process pressure to the pilot. Install shutoff
valves, vents, drains, or seal systems as needed in
the process pressure line. Install a needle valve in the
process pressure line to dampen pulsations.

Output Pressure

Connect output pressure piping to the connection
marked OUTPUT on the bottom of the pilot case as
shown in figure 4. Refer to the appropriate control
valve or actuator instruction manual to complete the
connection of output pressure piping from the pilot to
the loading connection of the control valve actuator.
suitable filtration equipment and the es-
tablishment of a maintenance cycle to
monitor its operation is recommended.
INCH
(mm)