Flojet 20378-015 Compression Spring, 0.24 x 0.56, Red
The Flojet 20378-015 is the genuine compression spring measuring 0.24" by 0.56", colour-coded red. It is the spring that sets the opening pressure of a Flojet bypass valve.
The colour coding is the practical detail. Springs that look almost identical can have very different rates, and rate is what determines the pressure at which the bypass lifts and starts recirculating flow. Flojet colours them so the correct one can be identified at a glance rather than measured — which matters because fitting the wrong spring gives a bypass that either never opens, leaving the pump working against a dead end, or opens too early, capping the pressure the system can reach.
The dimensions quoted are wire-to-wire figures rather than anything you would measure casually, so identification by colour and part number is more reliable than by ruler. Replace a spring that has taken a set, is corroded, or has been distorted during a previous service — a spring that has shortened permanently no longer produces its designed force, and the bypass opens lower than it should. Keep it clean on assembly and confirm the part number against the parts breakdown for your pump.
Key Features
- Genuine Flojet (Xylem) service part — correct rate for the bypass setting
- Colour-coded red for identification at a glance
- 0.24" x 0.56" compression spring
- Sets the pressure at which the bypass opens and recirculates flow
- Replaces a spring that has taken a set, corroded or been distorted
Applications
- Flojet bypass valve service and rebuild
- Restoring the correct bypass opening pressure
- Replacing a spring that has taken a permanent set
- Pump overhaul where the bypass has been disturbed
- Marine, dockside and mobile pressurised water systems
Specifications
- Brand: Flojet (Xylem)
- Manufacturer Part Number: 20378-015
- Part Type: Compression spring
- Dimensions: 0.24" x 0.56"
- Colour Code: Red
- Function: Sets bypass valve opening pressure
- Condition: New
Frequently Asked Questions
Q: Why are bypass springs colour-coded?
Because springs of different rates look nearly identical. The colour lets the correct one be identified without measuring, which matters when the wrong rate changes the pump’s whole behaviour.
Q: How can I tell if a spring has taken a set?
Compare its free length with a new one. A spring that has shortened permanently produces less force at the same compression, so the bypass opens below its intended pressure.
Q: Can I stretch a tired spring back?
No. Stretching changes the free length without restoring the rate, and the result is unpredictable rather than corrected.
Q: Does spring condition affect anything other than the bypass?
Indirectly. A bypass opening at the wrong pressure changes when the pump cycles and how it behaves at partial flow, which affects the pressure switch and the motor too.
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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