Refrigerating Specialties Division
3
Installation
All regulators are packed for maximum protection.
Unpack carefully, check the carton to make sure all
flanges and other items are unpacked. Save the
enclosed instructions for the installer and eventual
user.
Do not remove the protective coverings from the
inlet and outlet of the regulator until the regulator is
ready to be installed. Protect the inside of the
regulator from moisture, dirt and chips before and
during installation. When welded or brazed flange
connections are used, all slag, scale and loose
particles should be removed from the flange interior
before the regulator is installed between the flanges.
It is advisable to install a close-coupled companion
strainer (RSF) at the inlet of the regulator to help
protect it from any foreign material in the system.
The A4A series of regulators will give optimum
performance if mounted in a horizontal line in a
vertical position with the manual opening stem on
bottom. Where other positions are desired, the
factory should be consulted: please give application
and piping details. The regulator must be installed
with the arrow on the valve body pointing in the
direction of the fluid flow for the regulator to function
properly. Backward flow through the regulator is
uncontrolled and will vary with valve model and the
reverse pressure drop encountered. The regulator
is not a check valve.
Tighten the flange bolts and nuts evenly to provide
proper seating of the flange gasket and to avoid
damage to gaskets or flanges. (See Bolt Torque
Table). Avoid using the regulator flange bolts to
stretch or align pipe. Even the heavy duty body of
an A4A can be distorted, causing the precision parts
to bind.
The regulator should be installed in a location where
it is easily accessible for adjustment and mainte-
nance. The location should be such that the regula-
tor can not be easily damaged by material handling
equipment. When it is necessary to insulate the
regulator (and companion strainer), the insulation
should be installed to provide access to the regula-
tor (and companion strainer) for adjustment and
maintenance. Do not insulate the solenoid coil and
coil housing. Proper indicating gauges should be
installed to be easily visible to the operating engineer
for system checking and adjusting purposes.
Care should be exercised when locating the tem-
perature bulb and capillary tube to prevent damage
to either part. The selection of the bulb location is
important. It should follow generally accepted
practices. On installations where the bulb is
strapped to the line, the location of the bulb is at 12
o’clock for lines 1" outside diameter and smaller and
4 or 8 o’clock on larger lines. The lines must be
clean to assure good contact between bulb and line.
On steel lines, it is recommended that some type of
rust preventative method be used to minimize future
corrosion. Finally, the bulb should be insulated to
eliminate the effects of ambient air temperatures. If
more sensitivity is desired, a bulb well is recom-
mended. Do not locate the bulb in or near a trap in
the line. Liquid refrigerant may accumulate at this
point and feed an erroneous signal to the tempera-
ture bulb, causing erratic operation of the tempera-
ture regulator.
Disassembly and Assembly
Before disassembling any A4A type regulator, read
the information in this bulletin and Bulletin RSB,
Safety Procedures for Refrigerating Specialties
Division Refrigeration Control Valves.
Before a regulator is removed from the line or
disassembled in the line, make sure that all refriger-
ant has been removed from the regulator, including
the bonnet, where applicable, and the close-coupled
strainer. The regulator must be isolated from the
rest of the system in a safe manner. When pumping
down to remove the refrigerant, the manual opening
stem 33A must be turned out (counter clockwise) to
make sure the valve is open.
