Yamada 640013 O-Ring 13.6 mm x 2.4 mm, Buna-N
The Yamada 640013 is the factory o-ring specified for Yamada air operated double diaphragm pumps taking this O-ring size. 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.
The reason to replace these on sight is that a seal which looks serviceable often is not. Compression set leaves a flattened, glossy band where the ring sat, and a ring in that condition will seal a dry bench test and then leak the moment the pump sees pressure and vibration. Nicks from a screwdriver used to lever the old ring out are the other common cause, and they are invisible until the joint is back together and under load.
Key Features
- Genuine Yamada replacement o-ring
- Material: Buna-N (NBR), 70 durometer
- Nominal size: 13.6 mm x 2.4 mm
- Fits Yamada air operated double diaphragm pumps taking this O-ring size
- 4 per pump in the assemblies that use it
- Restores a positive seal at the joint without machining or adjustment
Applications
- Yamada air operated double diaphragm pumps taking this O-ring size
- 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: 640013
- Part Type: O-Ring
- Material: Buna-N (NBR), 70 durometer
- Nominal Size: 13.6 mm x 2.4 mm
- Fits: Yamada air operated double diaphragm pumps taking this O-ring size
- Quantity Used: 4 per pump
- 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.
CLRMarine
