Important:
As shown in the following figure, wrap the area where the braze connections meet the
valve body with a wet quenching cloth to reduce heat transfer to the valve body when you braze the
QREV braze connections.
Figure 9: Brazing the QREV brazed connector fittings
Installing the PSHC
To install the PSHC, use a 1/4 in. SAE external flare access valve with valve core in the correct orientation
at the evaporator outlet. When you install the PSHC on a horizontal copper line, install the access valve
and PSHC no more than 45° from the point perpendicular to the horizontal copper line to ensure contact
with vapor, not liquid, refrigerant. When you install the device on a vertical copper line, do not install
the PSHC at a downward angle. See Figure 10 and Figure 11 for the correct orientation for the PSHC and
access valve.
If there is no access valve in the correct orientation at the evaporator outlet, you must install a 1/4 in. SAE
external flare access valve with valve core in the correct orientation.
Note:
Complete the installation of the QREV, PSHC, and new liquid line filter drier before you apply
a vacuum and return the system to operation. See
for more information.
Flushing gases
You can use flushing gases such as dry nitrogen to flush the line with the PSHC in-line. However, the
unpowered PSHC is almost fully closed, and so allows flushing gases to leak and enter down stream of
the valve at very low flow rates.
Installing the access valve
When you install a 1/4 in. SAE external flare access valve with valve core, observe the following
guidelines:
• Follow all local, national, and regional codes related to refrigeration installation and refrigerants.
If you install these controls on equipment that contains hazardous or regulated materials, such
as refrigerants or lubricants, you must comply with all standards and regulations governing the
containment and handling of those materials.
• Install the access valve in the correct orientation. See Figure 10 and Figure 11 for correct PSHC and
access valve orientation.
• Remove the access valve core before you braze the access valve. It is best practice to use a valve core
with an access valve.
7
Quick Response Expansion Valve and Precision Superheat Controller Installation Guide
