Yamada 640130 O-Ring 24.5 mm x 3 mm, Buna-N for NDP-15 and G15
The Yamada 640130 is the factory o-ring specified for NDP-15 and G15 Series pumps. It seals one of the joints inside the pump, and because it costs almost nothing next to the downtime a leak causes, it is the kind of part worth replacing on sight rather than on schedule.
Getting the material right matters as much as getting the size right. The elastomer has to be compatible with what the pump is moving, because a seal attacked by the fluid swells, softens and extrudes out of its groove, and an incompatible ring can fail within hours rather than months. Check what the pump is actually handling before ordering, not what it handled when it was installed.
Key Features
- Genuine Yamada replacement o-ring
- Material: Buna-N (NBR), 70 durometer
- Nominal size: 24.5 mm x 3 mm
- Fits NDP-15 and G15 Series pumps
- 4 per pump in the assemblies that use it
- Restores a positive seal at the joint without machining or adjustment
Applications
- NDP-15 and G15 Series pumps
- Scheduled rebuilds and seal kit top-ups
- Chasing a weep at a joint face after reassembly
- Replacing a ring that has taken a compression set
- Service after a fluid change that attacked the old elastomer
- Marine, industrial and transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 640130
- Part Type: O-Ring
- Material: Buna-N (NBR), 70 durometer
- Nominal Size: 24.5 mm x 3 mm
- Fits: NDP-15 and G15 Series pumps
- Quantity Used: 4 per pump
- Series Port Size: 1/2 in on the NDP-15 Series
- Condition: New
Frequently Asked Questions
Q: Does the durometer number matter?
Yes. Hardness sets how far the ring deflects under a given squeeze. A softer ring in a groove designed for a harder one extrudes into the gap and nibbles away at the edge; a harder one in a soft ring groove may not fill the groove at all.
Q: Should I replace all the O-rings at once?
If the pump is open, yes. They are inexpensive next to the labor of opening the pump, they have all seen the same hours and the same fluid, and replacing one of a set usually means coming back for the others.
Q: What makes an O-ring swell?
Fluid absorption. The elastomer takes up the liquid it is sealing, grows, and eventually will not fit the groove. A ring noticeably larger than the new one is telling you the material choice is wrong for that service.
Q: Is a sleeve O-ring different from a body O-ring?
Functionally it is the same static seal, but the ones on the air valve sleeve see constant reversing pressure and a lot of cycles, so they are usually the first to go and are worth replacing whenever the air valve is stripped.
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 o-ring.
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