Yamada 771258-AP Abrasion Pad, neoprene for NDP-25
The Yamada 771258-AP is the genuine replacement abrasion pad specified for NDP-25 Series pumps running neoprene diaphragms. It is one of the pair of plates that sandwich the diaphragm and connect it to the center rod.
Disks also dish. Years of clamping load and thermal cycling leave the plate slightly cupped, and a cupped disk no longer clamps the diaphragm bead evenly, so the bead leaks and the diaphragm creeps out of the clamp. A disk laid on a flat surface should sit flat all the way round.
Key Features
- Genuine Yamada replacement abrasion pad
- Fits NDP-25 Series pumps running neoprene diaphragms
- Two per pump
- Clamps the diaphragm bead evenly on the center rod
- Smooth support rim so the diaphragm flexes where it should
- Direct replacement, no modification required
Applications
- NDP-25 Series pumps running neoprene diaphragms
- Diaphragm changes and liquid end rebuilds
- Replacing a disk with a burred or corroded rim
- Service after a sudden diaphragm failure
- Restoring even clamping on the diaphragm bead
- Marine, industrial and transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 771258-AP
- Part Type: Abrasion Pad
- Material: Neoprene (CR)
- Fits: NDP-25 Series pumps running neoprene diaphragms
- Quantity Used: Two per pump
- Series Port Size: 1 in on the NDP-25 Series
- Condition: New
Frequently Asked Questions
Q: How tight should the assembly be?
To the factory torque, no more. Overtightening pinches the diaphragm bead and starts a tear at the clamp line, which is one of the most common causes of a short diaphragm life.
Q: Can I clean up a rough rim rather than replace the disk?
Light polishing of a metal disk is acceptable if it leaves a smooth radius. Anything that leaves a sharp edge or removes the radius does more harm than the original burr.
Q: Does an abrasion pad do the same job?
No. A pad sits against the diaphragm to take abrasive wear on solids laden duty, extending diaphragm life. The disk carries the clamping load.
Q: Should both sides be replaced together?
If one disk is being replaced because of damage, check the opposite one closely. They share the same stroke and usually the same condition.
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 abrasion pad.
CLRMarine
