Back Pressure/Relief Valves

Inlet Connection:1/4″- 4″
Instrument Connection:True Union Socket, Threaded or ChemFlare, Spigot Bodies with Plain, Socket, Threaded or Flanges
Diaphragm:PTFE Bonded EPDM
Seats/Seals:EPDM, FPM


SB Series Back Pressure Relief Valves

Chemline’s SB Series back pressure relief valves are designed for long maintenance-free life. They are designed for superior performance in dosing systems. Different models are available. Each has advantages for different applications.

How they Work

Chemline SB Series Back Pressure/Relief Valves have two functions: as a back pressure valve, installed in-line downstream of a pump, the back pressure below the metering pump is maintained. When installed in the branch of a tee they are pressure relief valves. The valves stays closed until inlet pressure reaches the set pressure which is adjusted by turning the spring tensioning bolt. Inlet pressure acts against a PTFE bonded diaphragm, opening the seat to allow flow until the inlet pressure again equals the set pressure.

✓ Choice of PVC, Polypropylene or PVDF construction
Will handle a wide range of chemical applications and temperatures up to 100C (212 deg. F).
✓ Designed for superior Performance
High flow rates vs. overpressures
Low hysteresis (“backlash”)
No chatter
Long Cycle life

✓ True Union ends up to 2”
Easy Installation and maintenance
Leaky threads eliminated

✓ Sizes up to 4”

Back Pressure/Relief Valve Selection


ModelSizesTrue UnionChemFlareSet pressure RangeSizePrice ValueMajor Features
SB171/4″ – 3/8″Yes3/8″7.5 to 150 psiminigoodfits tight spaces
SB103/8″ – 2″Yes3/8″ – 1″3 to 60 psimediumgoodExcellent for Sodium hypochlorite
SB113/8″ – 2″Yes3/8″ – 1″7 to 150 psimediumgoodExcellent for Sodium hypochlorite
SB123/8″ – 2″Yes3/8″ – 1″5 to 150 psimediumgoodbuilt-in check function, unchanging opening pressure
SB122-1/2″-3″no7.5 to 150 psilargegoodbuilt-in check function, unchanging opening pressure
SB124″no7.5 to 90 psilargegoodbuilt-in check function, unchanging opening pressure
SB183/8″ – 2″Yes3/8″ – 1″7.5 to 150 psimediumbestrecommended for dosing – not too sensitive



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For detailed product information including pricing, availability, and additional documentation Contact Chemline

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