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 g)
lower. A 5 psid (.35 bar g) 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
g); Range B, 30 to 300 psig (2 to 21 bar g); Range C, 100
to 550 psig (6 to 38 bar g), Range D, 30-450 psig (2 to
31 bar g).
HA4A STANDARD REGULATOR
CONTROL MODULE STEM
MANUAL-OPENING STEM
DISC-PISTON
CLOSING SPRING
MAIN VALVE SEAT
CONTROL MODULE
RANGE SPRING
INTERNAL
EQUALIZATION
PASSAGE
GAUGE
INLET
PORT
M3W (OR M3) PILOT
AR1 BODY
HA4AL DIFFERENTIAL PRESSURE
REGULATOR
OPERATION
Inlet pressure is channeled
t h r o u g h t h e i n t e r n a l
equalization passage to
the dif ferential pressure
c o n t r o l m o d u l e . O u t l e t
p r e s s u r e ( o r o t h e r ) i s
introduced to the space
on top of the differential
pressure control module
diaphragm via an external
s e n s i n g t u b e . A r a n g e
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 dif ferential set ting. 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 por t 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 g).
M3L PILOT
AR1 BODY
OPERATION
Inlet pr es sur e is cha nnele d thr ough the inter na l
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 g) 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
suc tion p r e s sur e. Tur n the contr ol mo dule s te m
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 g); Range B, 30 to 300 psig (2
to 21 bar g); Range C, 100 to 550 psig (6 to 38 bar g),
or Range D, 30 to 450 psig (2 to 31 bar g). A vacuum
Range V, 20" to 130 psig (– 0.67 to +9 bar g) is also
available.
8
R429d
AUG 2015