Flojet 20028-008 Valve Chamber Sub-Assembly, Santoprene
The Flojet 20028-008 is the genuine Santoprene valve chamber sub-assembly, carried under the factory designation "Valve Chmbr S/A Sto". It renews the entire upper section of the pump where the inlet and outlet check valves live.
Buying the chamber as a sub-assembly rather than as loose valves is worth doing for a reason that is easy to overlook. The check valves do not simply need to be present — they need to sit flat on seats that are themselves unmarked. If a piece of grit has been dragged across a seat, or if a valve has been running hard against it for years, that seat can be scored or polished into a shape a new valve will not seal against. Fitting new flaps onto damaged seats gives a pump that is better for a few weeks and then no better at all. A complete chamber renews both halves of the sealing pair.
Santoprene is a thermoplastic elastomer chosen for its flexibility across a wide temperature range, its strong resistance to taking a permanent set, and its tolerance of water, detergents and dilute chemistries. Check the part number against the parts breakdown for your pump before ordering, and clean or fit a suction strainer at the same time if the old valves show cuts or embedded debris.
Key Features
- Genuine Flojet (Xylem) service part — complete valve chamber sub-assembly
- Renews the valve seats as well as the valves, not just half the sealing pair
- Santoprene for flexibility, set resistance and broad chemical tolerance
- Valves arrive correctly seated and oriented
- Factory designation: Valve Chmbr S/A Sto
Applications
- Flojet diaphragm pump rebuild and overhaul
- Pumps where the valve seats are scored or polished as well as the valves worn
- Restoring lost flow, pressure and priming
- Repairing valve damage after debris has reached the pump
- Marine, RV, dockside and mobile water systems
Specifications
- Brand: Flojet (Xylem)
- Manufacturer Part Number: 20028-008
- Part Type: Valve chamber sub-assembly
- Valve Material: Santoprene
- Factory Designation: Valve Chmbr S/A Sto
- Condition: New
Frequently Asked Questions
Q: How do I tell if a valve seat is damaged?
Look across it under a good light. A sound seat has an even, continuous ring of contact; a damaged one shows a scratch crossing that ring, or a dull polished band where the valve has worn in.
Q: Is it worth trying to clean up a marked seat?
On a moulded plastic seat, no. There is nothing to machine back to, and attempting to dress it usually makes the surface worse rather than flatter.
Q: Will a new chamber fix a pump that will not prime?
If the cause is leaking check valves, yes. If the pump still will not prime afterwards, look at the diaphragm and at air leaks on the suction side.
Q: How long should a set of valves last?
It depends almost entirely on water cleanliness. A system with a well-maintained strainer can run for years; one drawing gritty water can destroy a set in a season.
Not sure this is the right part? Send us a Picture of the pump plate on your pump and the CLR Marine team will confirm the correct part before you order.
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