SRL Service Manual 
Revision 00 
July 2007 
 
Page 58 of 56 
 
12.4 Adjusting the Hot Gas Bypass Valve 
 
The adjustment of the hot gas by-pass valve must be done without air flowing through the dryer.  The 
pressure should be set between 62.4 and 66.7 psig (
4.3 to 4.6 barg) for all models. 
 
•  Mount a precision pressure gauge on the ¼” schrader valve on the refrigerant tube at the outlet of 
the evaporator. Make sure to use as short a hose as possible on the gauge to avoid refrigerant 
losses which may affect the dryer performance, especially on smaller models. 
•  Remove the cap on the Hot Gas Bypass Valve. 
•  To increase the evaporation pressure, turn the regulating screw clockwise (loading the internal 
spring) 
•  To decrease the evaporation pressure, turn the regulating screw anti-clockwise (unloading the 
internal spring). 
•  After adjusting, wait a few minutes to allow the pressures to stabilise.  Re-adjust as necessary.