Refrigerating Specialties Division
6
operate with line voltage from 85% to 110% of rated coil voltage.
Operating with a line voltage above or below these limits may
result in coil burn-out. Also, operating with line voltages below
the limit will defi nitely result in lowering the valve’s maximum
opening pressure differential. Power consumption during normal
operation will be 33 watts or less. Note that no coil should ever be
energized when it is not securely mounted on the solenoid tube.
Inrush and running current is listed below:
Inrush Running
Fuse
Standard Coil
Current Current Size
Volts/Hertz
(Amps) (Amps) (Amps)
120/60 (Blue leads) 1.18 0.46 1
208/60 (Blue & Red leads 063 0.26 1
240/60 (Red leads) 0.60 0.23 1
440/60 (Yellow & Red leads) 0.39 0.13 1
115/50 (Yellow & Blue leads) 1.22 0.21 1
230/50 (Yellow leads) 0.65 0.26 1
Other
(Contact Factory)
(On transformer coil, the 6 volt leads are always black.)
Disassembly and Assembly
General Procedure (See Figs. 7, 8, 9, and 10)
Before disassembling any A4W type regulator, read the
information in this bulletin and Bulletin RSB (Safety Procedures
for Refrigerating Specialties Division Refrigeration Control
Valves).
Before a regulator is disassembled in the line, make sure that
all refrigerant has been removed from the regulator, including
the Bonnet (where applicable), the close coupled Strainer (if
used) and the adjacent pipes at the inlet and outlet of the valve.
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 11 must be turned in (clockwise) to make
sure that the valve is open.
All service or disassembly work is done from only the top side of all
A4W Regulators. The construction of the regulator and the method
of disassembly are relatively simple, but some procedures must
be followedto avoid damage or injury. The following describes the
procedure for the basic A4W: special instructions for other types
are included in the appropriate sections.
See Fig. 9 for S6A Pilot Solenoid Valve and Fig. 10 for A2D Pilot
Regulator Valve. See also Bulletin 23-06 for additional information
about the S6A Pilot Solenoid and the A2D Pilot Regulator Valves
.
Disassembly (See Figs. 7, 8 , 9 and 10)
Take care when removing Seal Caps 15 and 57 in case some
refrigerant may be trapped inside. Back the Adjusting Stem 52 all
of the way out (counterclockwise) to remove any pressure from
the Range Spring 49, otherwise damage to diaphragm 45 or Pilot
Seat 44 may occur. Remove Bonnet 51 by carefully removing Cap
Screws 58. Take care not to damage Diaphragm Follower 47.
Turn the Manual Opening Stem 11 all the way out (counterclockwise)
to stop. If for a 125 or 150mm (5” or 6”) Regulator, remove the
Adapter Cover 22 by carefully removing Bolts 17 and Nuts 18. If
for a 200mm (8”) Regulator, remove the Adapter Cover by carefully
removing Bolts 17. (Note: The Studs 19 found on the two smaller
sizes are not used on the 200mm (8”) size.) Carefully lift the
Adapter Cover away from the Body 1 by fi rst breaking the gasket
seal by inserting a fl at tipped screw driver between the two parts
and prying them apart, then lift the Adapter Cover off of the Body
1. On the 125 and 150mm (5” and 6”) valves, the two Studs 19 will
be retained in the Adapter Cover.
The Manual Opening Stem 11 can be removed from the Adapter
Cover 22 as follows: Remove Packing Nut 12 by turning it out
(counterclockwise) from the Adapter Cover. Slide the Packing Nut
over the Manual Opening Stem and then turn the Manual Opening
Stem in (clockwise) until the threads on the stem disengage from
the Adapter Cover. Remove the Manual Opening Stem from the
bottom side of the casting.
Push the Power Piston 9 down against the Closing Spring 8 force.
The Piston should move freely down and be returned by the
spring force. If the Piston is jammed or sticky, insert a US 1/4”-
20 machine screw into the tapped hole in the center-top of the
Piston and use this screw as a means of lifting the Piston from
place. (It may be helpful to know that the coil housing screw on a
standard Refrigerating Specialties solenoid valve is a 1/4-20 screw
that can be used for this purpose.)
If the Piston 9 cannot be removed as suggested above then use
the following procedure: Obtain a fl at steel bar approximately
10mm x 50mm (3/8” x 2”) x 50 (2”) longer than the diameter of the
piston bore. Drill a hole in the center of the fl at face that will clear
the 1/4”-20 screw. Obtain a 1/4-20 machine screw with a thread
the full length of the bolt that is at least 100mm (4”) long and a
1/4” hex nut. Place the bar across the top of the body bore, thread
the nut on to the machine screw and put the screw through the
clearance hole in the bar and thread it into the hole in the top of
the Piston. Snug the nut down against the bar and then, by further
tightening of the nut, pull the piston out of the body.
Examine the Seal Ring 10 for unusual wear and or tears. The
Seal Ring should appear as is illustrated in Fig. 11 which shows a
cross-section of the edge of the Piston 9 and the manner in which
the Seal Ring fi ts in the piston groove. Look at the bottom end
of the piston stem for signs of hammering or peening that could
be caused by an oversized regulator chattering as it attempts to
control a load far less than its capacity. If either the Seal Ring or
the Piston is damaged, they should be replaced and the cause of
the damage determined and eliminated.
The Valve Seat 2 on all A4W Regulators is removable. A US 3/8”-16
hex head Locking Screw 4 is used to hold the seat in position and
this must be removed using a 9/16 socket wrench. A Seat Wrench
6 is used to remove the Valve Seat. (Each valve size has its own
size Seat Wrench.) Position the prongs of the Modulating Plug so
that it is possible to place the wrench over opposite projections
on the top of the seat. Then, using a standard US 1/2” drive bar,
turn the seat counterclockwise until it comes free. The main valve
Modulating Plug 7 and the Closing Spring 8 can now be removed.
Examine the seating faces of the Valve Seat and the Modulating
Plug for uneven wear, nicks or non-uniform surfaces to determine
if either or both should be replaced. If it is necessary to replace
either part, determine and eliminate the cause of the wear that
necessitated the replacement.
Assembly (See Figs. 7, 8, 9 and 10)
To assemble the
Modulating Plug 7 and the Valve Seat 2 it is necessary to have the
appropriate size Seat Wrench 6 (each valve size has its own Seat
Wrench) and a new Seat O-Ring 3. Insert the Closing Compression
Spring 8 into the matching recess in the bottom of the Valve Body
1 so that it is in position to receive the bottom extension of the
Modulating Plug. Next insert the O-ring into position on the Valve
Seat and lightly lubricate with silicone grease. Put the Modulating
Plug through the Valve Seat and by grasping the prongs of the
Modulating Plug place both into the Valve Body so that the
Modulating Plug engages the Closing Spring and the Valve Seat
threads line up with the matching threads in the Body. Using the
Seat Wrench tighten the seat in place to the torque listed in the
table below. Finally, replace the Retaining Screw 4 and tighten with
a 9/16” socket wrench to the torque listed in the table below.
To replace the Seal Ring 10 on the Power Piston 9 install in place
by starting the new ring over the top of the Piston. Gradually
engage the ring into the slot, rotating the force on the ring as it is
pushed into place. The Seal Ring must be installed as shown in
Fig. 11 with the open edge of the ring pointing up.
Before installing the Power Piston 9 in the body bore be sure that
the bleed hole in the top of the piston is clear. Insert the Piston
into the Body 1 so that the top of the Piston is parallel with the
top of the Valve Body and, with an even force, push the Piston
into the Body. There is no fasteningbetween the Piston and the
Modulating Plug 7; the Piston Stem only slides into the receptacle
in the center of the Modulating Plug. The Piston should not bind
and must move up and down easily.
If the Manual Opening Stem 11 has been removed, it must be
re-installed before the Adapter Cover 22 is installed. Insert the
Opening Stem into the opening on the bottom of the Adapter
Cover and push it through the Stem Packing 13 until it is ready to
engage with the threads in the casting. Grasp the Stem at its top
end and pull while, at the same time, turning it counterclockwise
(when viewed from the top of the Stem) to begin to engage the
threads, and, then, complete the turning with a wrench until the
bottom of the stem is about fl ush with the bottom of the Adapter
Cover. Install the Packing Nut 12 at the top of the Stem.
