Relief Valves
Parker Relief Valves are designed such that when upstream pressure exceeds the closing force exerted by the spring,the lower stem opens,permitting flow through the valve.
Parker Relief Valves Series
RL4 Series
• Handle for field maintenance
• Externally adjustable pressure settings
while valve is in operation
• Color coded springs and labels indicate
spring cracking range
• Manual override option with positive stem
retraction is available for the full working
pressure range
• Seven different springs
RH4 Series
• Eight springs
• Manual override option with positive stem
retraction is available for pressures up to
1,500 psi (103 bar)
• Preset from factory and comes with
standard springs
HPRV – PED High Pressure Proportional Relief Valve
• Captured moulded seat design is blow-out
and chip resistant
• Color coded springs and labels indicate
spring cracking range
• Unique Tru-Loc facility prevents accidental
adjustment
• Low friction stem seal design prevents
friction which increases accuracy of
cracking pressure and reseat pressure
• Balanced poppet design ensures
consistent cracking pressure regardless of
system back pressure
• Multiple end connections available
HPRV – PED Low Pressure Proportional Relief Valve
• Pressure settings are externally adjustable.
Six different spring ranges provide greater
system sensitivity and enhanced
performance
• Back pressure has minimum effect on
cracking pressure
• Color coded springs and labels indicate
spring cracking range
• Orifice sizes: 5.2mm (0.203")
• Lock wire feature secures a given pressure
setting
• Multiple end connections available
