Yamada 771363 Hytrel Diaphragm for NDP-25
The Yamada 771363 is a genuine Yamada diaphragm, Hytrel (TPEE), used in NDP-25 series air-operated double diaphragm (AODD) pumps. It separates the air side of the pump from the wet side, and is the only moving part in direct contact with both. It is normally the component that sets the service life of the whole pump, failing from flex fatigue, chemical attack, or running dry against a closed valve.
Genuine Yamada replacement parts are machined and molded to the original factory tolerances, so fit, alignment and seal engagement match the component being replaced. Two per pump - always replace in pairs. Always compare the exact part number against your pump's nameplate before ordering, since Yamada varies internal components by both pump size and body material / elastomer combination.
Key Features
- Genuine Yamada replacement diaphragm
- Material: Hytrel (TPEE)
- Fits NDP-25 series AODD pumps
- Two per pump - always replace in pairs
- Molded or machined to factory tolerances for correct fit and seal engagement
Applications
- NDP-25 series AODD pump service and rebuilds
- Scheduled preventive maintenance
- Restoring lost flow, leaks, or erratic cycling
- Marine, industrial, chemical and wash-down service
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 771363
- Part Type: Diaphragm
- Material: Hytrel (TPEE)
- Fits: NDP-25 Series
- Condition: New
Frequently Asked Questions
Q: What causes this kind of wear part to fail?
Flex fatigue from normal cycling, chemical attack from the pumped fluid, or heat and hardening over time. Whichever it is, the fix is the same: replace it, and note which failure mode it was so the replacement material can be matched to the service.
Q: How do I know which elastomer is right for my fluid?
Match it to what is already on the pump nameplate or the failed part you are replacing, and check chemical compatibility against the fluid being pumped. Buna-N suits oils and fuels, EPDM suits water and many chemicals, Viton and PTFE suit aggressive or high-temperature service, and Santoprene and Hytrel give long flex life on general duty.
Q: Can I run the pump a little longer before replacing a worn part?
You can, but a part that has started to degrade wears the components around it faster, so a delayed replacement often turns a small parts order into a larger rebuild.
Q: Should I replace just this one part or the matching set?
Replace the matching set (both check balls, both diaphragms, or all the seats/gaskets disturbed in the rebuild) at the same time. Parts that run the same duty cycle wear together, and replacing only the failed one is the most common reason a rebuild needs redoing soon after.
Not sure this is the right part? Send us a picture of your Pump Plate to https://www.clrmarine.com/Contact-Us and the CLR Marine team will confirm the correct diaphragm.
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