Brochure

Parker Hannifin Corporation
Climate & Industrial Controls Group
Cleveland, OH
Catalog CIC-2003-1/US
Thermostatic and Constant Pressure (Automatic) Expansion Valves
186
Thermal Electric ValvesInstallation Information
Mounting Position – The valve should be installed
such that the thermal head is within 30° of an upright
position to insure maximum capacity.
Sweat Soldering – The same precautions should be
used when sweating this valve into a system that
would normally be used with conventional valves to
prevent excessive temperature build up (damp cloth –
chill block – and so on).
Thermistor Suction Line Adapter – The thermistor
should be located flush, or slightly less, with the inside
wall of the suction line. The 5/16" dimension shown in
the second illustration at the right will correctly locate
the thermistor assembly with the inside wall of the suc-
tion line. Projection of the female adapter fittings, as
well as the thermistor assembly, into the suction line
should be avoided (see the illustration at the right).
Thermistor Location & Sensing Positions – The
liquid sensing thermistor assembly can be used in any
suction line with a diameter of 1/2" or larger. It will work
on both vertical and horizontal suction lines, but should
never be located where liquid refrigerant is likely to
accumulate or trap off. For instance; in a bottom U-
Bend connecting two vertical risers (see the bottom
graphic at the right).
Since suction refrigerant flow depends upon many
factors including suction line size, suction gas velocity,
elbows, reducers, etc.; it is important to establish firm
rules regarding the best location of the liquid sensing
thermistor.
The following observations have been made on a wide
variety of applications and have proven to be useful
guidelines for locating thermistor assemblies in suction
lines.
1. High velocity suction locations are preferable over
low velocity locations.
2. Smaller diameter suction locations are preferable
over larger diameter locations.
3. Unless the flow pattern around an elbow or reducer
is well known or specifically designed for the liquid
sensing thermistor assembly, it is best to stay at
least 6 inches away when locating downstream of
them.
4. Vertical suction lines make excellent locations, but
trapping should be avoided as mentioned earlier
(see the bottom graphic at the right).
(Continued on the following page.)
Thermal Electric Valve Model 625 Installation
Correct Placement of Thermistor Assembly into Suction
Line
Suction Line Identifying Location of Thermistor
Assembly
Note: Use refrigerant
compatible pipe sealant
on threads. Do not apply
sealant to end of
thermistor.
Correct and Incorrect Locations for Thermistor
Assembly
Incorrect location
Correct locations