Brochure

Catalog CIC-2003-1/US
Refrigeration Solenoid Valves
Parker Hannifin Corporation
Climate & Industrial Controls Group
Cleveland, OH
263
Refrigeration
Solenoid Valves
Technical Information Solenoid Valves for Secondary Coolants
Solenoid Valves for Secondary Coolants
For Supermarket Refrigeration
Description
Parker Hannifin, a pioneer in supermarket refrigeration
control, introduces a new line of solenoid valves to control
secondary coolants. These fluids include propylene glycol,
ethylene glycol, Pecasol 50, Dynalene HC-40, and others.
Parker's valve is the only valve designed to meet the
requirements of both medium and low temperature
applications encountered in supermarket applications.
What is Secondary Cooling?
In a secondary coolant, or secondary loop system, a chilled
solution, such as propylene glycol, is circulated throughout
the system rather than liquid refrigerant. Secondary coolant
systems are advantageous because they can eliminate
liquid refrigerant and suction gas lines running through
a store. This reduces installation costs and labor, and
eliminates costly refrigerant leaks.
Also, PVC tubing can be used, rather than the heavier,
more expensive copper tubing normally used in traditional
systems. Again, this reduces installation costs and labor,
and eliminates costly refrigerant leaks.
Another benefit is more efficient defrost cycles with less
potential product damage.
Minimum Pressure Drop
In order to achieve good heat transfer through a coil surface,
minimizing pressure drops throughout the system is critical.
Parker secondary coolant valves do not require a minimum
pressure to operate.* This is because of the valve's unique
“hung diaphragm” design. Other pilot operated valves re-
quire some minimum pressure drop to open the diaphragm
or piston. This minimum pressure drop is a pressure loss,
and means less pressure available at the coil. When using
Parker’s secondary coolant valves, valve size can be
maximized, minimizing the pressure drop.
*The 34E24C2-R1021E requires a minimum of 5 psi.
Features
• Suitable for both medium and low
temperature systems — ethylene propylene
diaphragm and seals are compatible with
secondary fluids.
• Less maintenance and more dependability
result from the NEMA 4 coils that protect
against water, icing and vibration.
• Pressure drop (loss) is minimized by the
unique hung diaphragm construction,
eliminating the need for a minimum pressure
differential.
• Quantity and quality of fluid flow is ensured
by the large Cv rating that accurately
matches fluid to flow characteristics.
• Easily matches up to system piping. Valves
are available in sizes 5/8" to 2-1/8" ODF,
ensuring that a valve is available for every
common line size.
• Easy brazing and faster installation possible
with the copper sweat connections which
eliminate the need for pipe threaded
connections and associated leaks.