Johnson Controls Tyco PRV-1A - Page 4

TFP1581
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LOWER SET PRESSURE CONDITION
HIGHER SET PRESSURE CONDITION
DIAPHRAGM
CHAMBER
DIAPHRAGM
CHAMBER
SUPPLY
PRESSURE
WATERFLOW
LOWER
SET REDUCED
PRESSURE
WATERFLOW
HIGHER
SET REDUCED
PRESSURE
WATERFLOW
SUPPLY
PRESSURE
WATERFLOW
UPSTREAM
WATER SUPPLY
PORT TO
P1 PILOT VALVE
DOWNSTREAM PORT
ADJUSTED PRESSURE
WATERFLOW TO AND FROM
P1 PILOT VALVE
DOWNSTREAM PORT
ADJUSTED PRESSURE
WATERFLOW TO AND FROM
P1 PILOT VALVE
UPSTREAM
WATER SUPPLY
PORT TO
P1 PILOT VALVE
GREATER
RESTRICTION OF
PRV-1A VALVE
WATERWAY
LESSER
RESTRICTION OF
PRV-1A VALVE
WATERWAY
LOWER ADJUSTED
SPRING TENSION
HIGHER ADJUSTED
SPRING TENSION
CONTINUOUS
PRESSURE
ADJUSTMENT
TO DIAPHRAGM
CHAMBER
GREATER
FORCE ON DIAPHRAGM
DECREASES PRV-1A VALVE
WATERWAY
LESSER
FORCE ON DIAPHRAGM
INCREASES PRV-1A VALVE
WATERWAY
PRESSURE
SENSING
(FAR SIDE PORT)
TO AND FROM
PRV-1A VALVE
DOWNSTREAM
PORT
CONTINUOUS
PRESSURE
ADJUSTMENT
TO DIAPHRAGM
CHAMBER
WATER
SUPPLY THROUGH
RESTRICTION ORIFICE
(NEAR SIDE PORT)
WATER
SUPPLY THROUGH
RESTRICTION ORIFICE
(NEAR SIDE PORT)
PRESSURE
SENSING
(FAR SIDE PORT)
TO AND FROM
PRV-1A VALVE
DOWNSTREAM
PORT
LESS FREQUENT
CYCLING OF SEAL
ASSEMBLY DUE
TO HIGHER SPRING
TENSION MAINTAINS
HIGHER PRESSURE
IN PRV-1A VALVE
DIAPHRAGM
CHAMBER
MORE FREQUENT
CYCLING OF SEAL
ASSEMBLY DUE
TO LOWER SPRING
TENSION MAINTAINS
LOWER PRESSURE
IN PRV-1A VALVE
DIAPHRAGM
CHAMBER
P1 PILOT
VALVE
P1 PILOT
VALVE
FIGURE 4
MODEL PRV-1
A PRESSURE REDUCING VALVE
OPERATION