Bulletin 30-21
–
Page 3
3-Way Heat Reclaim Valves
B5D, 8D, 12D, 16D, 8D-HP, 12D-HP,
SB5D, S8D, S12D, S16D, S8D-HP, S12D-HP
OPERATION
“B” Type
Normal (Outdoor) Condenser - De-en er gized
See Figure 1. With the pilot valve de-energized, high side
pressure is pre vent ed from entering the cavity above the
piston assembly. At the same time, the upper pilot port is
open to suction pressure. The re sult ing pressure differential
across the piston moves the piston-seat assembly to close
the reclaim condenser port (up per main port). In this mode,
the refrigerant flows to the normal condenser. The pilot valve
opens the cavity above the piston to suction. This allows the
reclaim condenser to be pumped out through a small bleed
hole in the piston. The pump out process reduces the reclaim
condenser to suction pressure. Once suction pressure is
reached, the flow through the bleed hole in the piston stops.
There is no high to low side bleed with continued operation in
the normal condenser mode. For a more efficient pump out
of the reclaim condenser, a normally open solenoid valve can
be added to the lowest physical location of the reclaim coil to
remove liquid.
“C” Type
Normal (Outdoor) Condenser - De-energized
With the pilot valve de-energized, high side pressure is
pre vent ed from entering the cavity above the piston-seat
assembly. At the same time the upper pilot port is opened to
suction pressure. The re sult ing pressure differential across
the piston moves the piston-seat as sem bly to close the
reclaim (up per) main port, thereby eliminating high to low
side bleed and the resulting capacity loss with the system in
the normal condenser mode.
“B” and “C” Type
Reclaim (Reheat) Condenser - Energized
When the pilot valve is energized, high side pressure is per mit-
ted to flow through the lower pilot port at the same time the
Type
Port
Size
Connection
ODF Solder
Inches
A
B
C
D
E
F
G
H
J
(S)B5D5B
(S)B5D5C
5/8
5/8
5.00
(127)
4.36
(111)
3.22
(82)
3.22
(82)
0.79
(20)
3.84
(98)
0.50
(13)
2.94
(75)
1.64
(42)
(S)8D7B(-HP)
(S)8D7C(-HP)
3/4
7/8
5.18
(132)
5.06
(129) 3.44
(87)
3.44
(87)
1.13
(29)
2.63
(67)
0.75
(19)
2.89
(73)
(S)8D9B(-HP)
(S)8D9C(-HP)
1-1/8
5.13
(130)
0.91
(23)
(S)12D11B(-HP)
(S)12D11C(-HP)
1-1/4
1-3/8
6.87
(174)
6.94
(176)
4.19
(106)
4.19
(106)
2.38
(60)
4.25
(108)
0.97
(25)
(S)12D13B(-HP)
(S)12D13C(-HP)
1-5/8
1.09
(28)
(S)12D17B(-HP)
2-1/8
1.25
(32)
(S)16D17B
(S)16D17C
2
2-1/8
8.18
(208)
9.53
(242)
5.47
(139)
5.47
(139)
3.50
(89)
5.44
(138)
1.25
(32)
3.17
(81)
upper pilot port is closed to suction. High side pressure build
up on top of the piston moves the piston-seat assembly to
close the normal con dens er port and open the reclaim (upper)
main port. With the upper pilot port closed, there is no high to
low side bleed and resulting ca pac i ty loss with the system in
the reclaim mode.
Valves using the MKC-1 coil may be used on fluids or gases
where the temperature does not exceed 240°F (116°C), while
the valve ambient is 120°F (49°C). The coil is Underwriters
Laboratory Class F rated.
INSTALLATION
Piping Suggestions
Valves must be installed in a horizontal or vertical position
with the coil level with or above the valve body. Install Heat
Reclaim Valves so the con nec tions are in the proper flow
direction as shown in Figure 2.
DIMENSIONS – Inches (mm)
Suction
Reclaim
Condenser
Compressor
Discharge
Normal
Condenser
1/4” ODF
A
B
E
G
Optional 1/2”
Conduit Boss
J
F
H
Figure 2
D
C
Compressor
Discharge
Suction
Reclaim
Condenser
Bleed Hole
“B” TYPE
RECLAIM CON DENS ER
PUMP OUT
Figure 1
