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INSTRUCTIONS R429d
Dec 2003
HA4A STANDARD REGULATOR
OPERATION
Inlet pressure is channeled through the internal
equalization passage to the inlet pressure control
module. The valve modulates open when inlet pressure
exceeds the pressure setting on the control module.
The gas or liquid passes through the inlet pressure
control module to enter the space on top of the piston,
which forces the main valve seat to open and regulate
flow. As inlet pressure increases, the main valve seat
opens further to maintain the selected inlet pressure. A
minimum pressure difference of 2 psi (0.14 bar) is
adequate to fully open the main valve. When inlet
pressure decreases below the pressure setting on the
control module, the closing spring will cause the main
valve seat to throttle closed.
ADJUSTMENT
Connect a pressure gauge via a gauge valve at the
gauge port on the regulator adapter. Set the control
module range spring at minimum force (control module
stem turned counterclockwise). Operate the refrigeration
compressor system and achieve approximate desired
suction pressure. Turn the control module stem clockwise
until a slight increase in inlet pressure is detected by
the gauge. The inlet pressure setting can now be
increased by turning the control module stem clockwise
or decreased by turning it counterclockwise. The system
should be allowed to operate for a period of time before
the final adjustment is made. The inlet pressure control
module is available in Range A, 0 to 150 psig (0 to 10
bar); or Range B, 30 to 300 psig (2 to 21 bar). A
vacuum Range V, 20" to 130 psig (–0.67 to +9 bar) is
also available.
HA4AK RESEATING RELIEF REGULATOR
OPERATION
(Same as HA4A) Inlet pressure is channeled through
the internal equalization passage to the reseating relief
control module. When inlet pressure exceeds the relief
setting, the control module opens wide to allow pressure
to enter the space on top of the piston. This causes the
main valve seat to open and relieve the inlet pressure,
provided the outlet pressure is at least 2 psi (0.14 bar)
lower. A 5 psid (.35 bar) closing spring is standard on
¾" through 1¼" valves. See page 6 for M3K pilot details.
When used for defrost relief from low side to an
intermediate pressure, a check valve on the outlet is
required to prevent back flow during refrigeration.
ADJUSTMENT
The control module is nonadjustable, factory-set and
sealed. Available in Range A, 0 to 150 psig (0 to 10
bar); or Range B, 30 to 300 psig (2 to 21 bar).
HA4AL DIFFERENTIAL PRESSURE REGULATOR
OPERATION
Inlet pressure is channeled through the internal
equalization passage to the differential pressure control
module. Outlet pressure (or other) is introduced to the
space on top of the differential pressure control module
diaphragm via an external sensing tube. A range spring
on the top of the control module diaphragm allows the
control of the differential between inlet and outlet
pressure. Increased range spring force increases the
differential setting. Inlet pressure, counteracted by the
range spring plus outlet pressure, enters the space on
top of the piston which forces the main valve seat to
open and regulate flow. The external sensing tube on
the 5" & 6" valves must be customer supplied and field
installed.
ADJUSTMENT
Connect a pressure gauge via a gauge valve at the
gauge port on the regulator adapter for the inlet pressure
reading. A pressure gauge downstream is also required.
With the control module range spring force at the
minimum (control module stem turned fully
counterclockwise, at this point pressure differential is
at minimum), slowly turn the control module stem
clockwise until the desired pressure difference between
the two gauges is achieved. A final adjustment should
be made after system has operated for a period of time.
The system must be capable of generating the desired
pressure difference for the regulator to open. Range A,
0 to 150 psig (0 to 10 bar).
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