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Component Operation and Maintenance
45
To raise the head pressure setting, turn the adjusting screw counterclockwise until the desired set-
ting is obtained.
Figure 24 Johnson Controls valve adjustment
Manual Flushing—The valve may be flushed by inserting a screwdriver or similar tool under the
two sides of the main spring and lifting. This action will open the valve seat and flush any dirt parti-
cles from the seat. If this fails, it will be necessary to disassemble the valve and clean the seat.
High Pressure Valve - 350 PSIG System (2413 kPa) for 3 Ton Units (Metrex Valve)
Adjustment—The valve may be adjusted using a 1/8" diameter rod. Turn adjusting collar nut coun-
terclockwise to raise head pressure. Turn it clockwise to lower head pressure. Rotation directions are
as viewed from top of valve spring housing.
Figure 25 Metrex valve adjustment
Range
Spring
Valve
Spring
Guide
Top
Retainer
Range Adjustment Screw
Insert screwdrivers under
the valve spring guide.
Adjusting Collar Nut