Brochure

Bulletin 30-10 / Page 17
22, 134a, 401A, 402A, 404A, 407C, 502, 507 Built-In Check Valve Series
Type CMB19S2
Type CE14S250
LIQUID
SUCTION
DISCHARGE
Figure 2
Replaceable
Catch-All
See-All
Receiver
OLDR
Liquid
Differential
Valve
Liquid Line
Solenoid Valve with
Check Valve Feature
Liquid Line
Solenoid Valve
Check Valve
Check Valve
Evaporator
Check Valve
Evaporator
TEV
TEV
Distributor
Suction Header
Defrost Header
3-Way 10G711B
Defrost Valve
2-Way Solenoid
Defrost Valve
SORIT-, CDS-, Suction
Throttling Valves or Solenoid
Stop Valve for Defrost
Application
A solenoid valve with a built-in check valve is de-
signed to replace a liquid line solenoid valve in paral-
lel with a check valve for reverse flow. This valve
may be applied in the liquid line of a supermarket
case for positive shutoff during pumpdown control,
while allowing full flow in the reverse direction dur-
ing reverse gas defrost. It may also be used in the
liquid line of a heat pump to prevent migration of re-
frigerant to the outdoor unit during the heating mode,
while allowing full flow in the reverse direction dur-
ing the cooling mode. CAUTION: This valve will not
close in the reverse flow/cooling mode.
See Figure 1. The check ball is small and inserted into
the pilot port of the disc. When the valve is energized
for operation in the refrigeration flow direction, the
pressure on top of the disc is bled off through the
pilot port and the disc raises. When the evaporator
goes into defrost or the heat pump switches to the
cooling mode, the solenoid valve must be ener-
gized. The reverse flow causes the check ball to
close the pilot port from the bottom, pushing the disc
up, fully opening the valve.
The check valve disc also requires a modification in
the stem and plunger assembly. Therefore, the disc
and stem and plunger assembly must be changed
to convert a standard solenoid valve to one with a
built-in check valve. Internal parts kits are available
for solenoid valves with the built-in check valve. See
Bulletin 122, Replacement Parts.
For Supermarkets
See Figure 2. For reverse gas defrost, a liquid line
solenoid valve can be installed with a check valve
in parallel, to allow reverse flow to the liquid
header. This adds the expense of labor and materi-
als. Or, a Sporlan liquid line solenoid valve with the
built-in check valve feature can be installed, saving
time and money.
For Heat Pumps
This valve may be used on some heat pump applica-
tions when sized correctly. (Refer to capacities at 40°F
evaporator temperature, see Page 18 of this Bulletin.)
For heat pumps with long lines that require shut off
in both directions, use two solenoid valves with the
outlets pointing towards each other.
Fig ure 1
CME14S2* REVERSE FLOW SOLENOID VALVE
List ed
RE FRIG ER A TION
CHECK BALL
PI LOT PORT
DISC
DEFROST
STEM & PLUNG ER
ASSEMBLY
*
The “C” is used in this nomenclature to represent the check valve
feature. See Solenoid Valve Nomenclature, Pages 25-26.