Flojet 20378-012 Bypass Kit, 50 PSI
The Flojet 20378-012 is the genuine bypass kit set for 50 PSI. The bypass opens once discharge pressure reaches that figure, returning flow to the inlet rather than allowing pressure to keep rising against a closed outlet.
What a bypass really buys you is smooth behaviour at partial flow. A diaphragm pump with no bypass has only two states: pumping, or stopped by its pressure switch. Open a tap slightly and the pump cannot deliver such a small amount steadily — it builds pressure, cuts out, the pressure falls, it cuts back in, and the result is the familiar pulsing trickle. A bypass gives the pump somewhere to send the surplus, so it keeps running steadily and the outlet delivers a constant stream.
Fifty PSI is a moderate setting, comfortable for systems that need more pressure than domestic fresh water service without going into genuinely high-pressure territory. Check the figure against your pump’s specification: a bypass set above what the pump can produce never opens, while one set too low caps the pressure the system can reach. Confirm the part number against the parts breakdown before ordering.
Key Features
- Genuine Flojet (Xylem) service part — correct pressure setting and fit
- 50 PSI bypass setting for moderate-pressure systems
- Cures the pulsing trickle a pump gives at small partial flows
- Lets the pump run steadily instead of cycling on its pressure switch
- Protects the motor from working against a closed outlet
Applications
- Flojet systems specifying a 50 PSI bypass
- Installations where outlets are often only partly opened
- Spray and washdown equipment with trigger control
- Curing pulsing delivery and frequent switch cycling
- Marine, dockside and mobile pressurised water systems
Specifications
- Brand: Flojet (Xylem)
- Manufacturer Part Number: 20378-012
- Part Type: Bypass kit
- Pressure Setting: 50 PSI
- Function: Recirculates flow once the set pressure is reached
- Condition: New
Frequently Asked Questions
Q: Why does a pump pulse at low flow?
Because without a bypass it cannot deliver a small steady amount. It builds pressure, the switch cuts it out, pressure falls, and it starts again — producing a pulsing stream.
Q: Does a bypass replace the need for an accumulator?
They overlap but are not the same. A bypass handles continuous partial flow; an accumulator handles brief draws without starting the pump. Many systems benefit from both.
Q: Can a bypass be adjusted?
These kits come set, and adjusting by feel usually makes matters worse. Choose the kit with the setting the system needs rather than altering one.
Q: How do I know if my bypass has failed?
The pump starts cycling at partial flow again, or it can no longer reach its normal working pressure because the bypass is stuck open.
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
