Flojet 20028-042 Valve Chamber, Buna Non-Fabric
The Flojet 20028-042 is the genuine valve chamber with plain Buna valves, carried under the factory designation "Vlv Chmbr N/F Buna 2BP". The N/F designation identifies the non-fabric version — plain elastomer rather than the fabric-reinforced alternative.
The two constructions exist because they suit different duties, and neither is simply better. A plain elastomer flap is softer and more compliant, so it seats readily against its seat and seals well at low pressures without needing much force to close it. A fabric-reinforced flap is stiffer and holds its shape under higher pressure, but that same stiffness makes it less eager to seal when there is little pressure behind it. For gentle, low-pressure and demand-water duties, the plain version is very often the better-performing choice.
Buna-N brings resilience, good recovery after compression and useful abrasion resistance for fresh water, washdown, detergents and dilute solutions, while being the wrong choice for heat, ozone and aggressive chemistry. Fit the kit that the parts breakdown specifies for your pump rather than choosing by construction, check the valve seats for scoring while the chamber is apart, and clean or fit a suction strainer if grit has been reaching the pump.
Key Features
- Genuine Flojet (Xylem) service part — complete valve chamber
- Non-fabric (plain) Buna valves — compliant and quick to seal at low pressure
- Resilient and abrasion-resistant for fresh water and washdown duty
- Recovers its shape well after compression, resisting permanent set
- Factory designation: Vlv Chmbr N/F Buna 2BP
Applications
- Flojet diaphragm pumps in demand water and low-pressure duty
- Fresh water, washdown and general utility service
- Restoring flow and pressure lost to worn check valves
- Systems where valves must seal readily with little pressure behind them
- Marine, RV, dockside and mobile water systems
Specifications
- Brand: Flojet (Xylem)
- Manufacturer Part Number: 20028-042
- Part Type: Valve chamber
- Valve Material: Buna-N (nitrile), non-fabric
- Factory Designation: Vlv Chmbr N/F Buna 2BP
- Condition: New
Frequently Asked Questions
Q: Is a plain valve weaker than a reinforced one?
Not weaker for its intended duty — softer. That compliance is an advantage at low pressure and a limitation at high pressure, which is why both versions are listed.
Q: Can I substitute a reinforced kit for more durability?
Only if it is listed for your pump. A stiffer valve in a low-pressure pump can seal less readily, costing you priming performance in exchange for durability you may not need.
Q: What ends the life of a plain Buna valve?
Hardening with age and heat, taking a permanent set so it no longer lies flat, or being cut by grit. All three produce the same symptom: backflow on every stroke.
Q: Should the seats be inspected at the same time?
Always. A new valve on a scored seat will seal poorly from the start, and there is no way to check it once the chamber is closed up.
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.
CLRMarine
