Berkeley M13910 O-Ring for Engine-Driven Pump Body
The Berkeley M13910 is the genuine replacement pump body o-ring for Berkeley engine-driven centrifugal pumps. It is the static seal captured in the groove between the pump body and its mating casing or cover. When the pump is bolted back together the ring is squeezed into that groove and forms a continuous leak-tight joint around the whole circumference of the wet end. It never rotates and it never wears in the way a shaft seal does, which is exactly why it is so easy to overlook.
When a body o-ring gives up it fails in two directions, and only one of them is obvious. The visible failure is water escaping outward as a weep or a drip at the joint. The far more troublesome failure is air being drawn inward on the suction side, because a centrifugal pump cannot move air. A self-priming unit that takes an age to catch, surges as it runs, or loses its prime overnight is very often pulling a small amount of air past a flattened body ring. Nothing drips, nothing looks wrong, and people replace shaft seals and impellers chasing a fault that lives in a rubber ring worth a fraction of either.
Rubber takes a compression set over time. Left clamped in one position for a few seasons and warmed by the pumped water and the sun, it stops springing back and simply keeps the flattened shape it was squeezed into. Age, heat and any petroleum contamination harden it further, and disassembly frequently nicks it. For that reason the accepted practice is to fit a new body o-ring every single time the wet end is opened, whatever the old one looks like. Wipe the groove and both faces clean, give the new ring a light smear of silicone grease so it stays put while you close the pump up, and pull the fasteners down evenly in a cross pattern.
Key Features
- Genuine Berkeley (Pentair Pump Group) service part - correct diameter and cross-section for the body groove
- One-piece moulded ring - no splicing, joining or cutting to length
- Seals the wet-end body joint against both outward leakage and inward air ingress
- A correctly sized ring seats in its groove instead of extruding under pressure the way an approximate substitute does
- Inexpensive insurance against having to open the pump a second time
Applications
- Berkeley engine-driven centrifugal pumps
- Routine reassembly after shaft seal, impeller or diffuser work
- Curing a weep or drip at the pump body joint
- Tracing slow priming, surging or overnight loss of prime caused by air ingress
- Winter layup, recommissioning and spares kits
- Pump repair shops and service centres
Specifications
- Brand: Berkeley
- Manufacturer: Pentair Pump Group
- Manufacturer Part Number: M13910
- Part Type: O-ring, pump body
- Seal Type: Static (non-rotating)
- Form: One-piece moulded ring
- Application: Engine-driven centrifugal pump body joint
- Condition: New
Frequently Asked Questions
Q: Should I use gasket sealant on it as well?
No. An o-ring seals purely by being compressed into its groove, and sealant can hold it off its seat or push it out of position as you close the joint. It also makes the next strip-down considerably messier. A thin film of silicone grease is all it should ever see.
Q: The joint still weeps after fitting a new one. What now?
Nine times out of ten the ring was pinched or rolled out of its groove as the halves came together. Take it apart and look for a flat spot or a cut on the ring. Also run a fingertip around the groove and the mating face for corrosion pits or a nick, since either will track water past a perfect seal.
Q: Does this seal the shaft too?
No. This is a body seal only, and it seals between two parts that do not move relative to each other. Where the rotating shaft passes out of the wet end, sealing is handled separately by a mechanical shaft seal or by a packed stuffing box, depending on how your pump was built.
Q: How should I store a spare?
Flat, loose, in the dark and away from heat, ozone sources such as electric motors, and any oil or fuel. Do not hang it on a nail or leave it stretched over something, and do not keep it in a hot engine bay. Stored properly a spare stays serviceable for years.
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 body o-ring before you order.
CLRMarine
