Yamada 771525 Check Valve Ball, Buna-N for DP-15 and NDP-15
The Yamada 771525 is the genuine check valve ball for DP-15 and NDP-15 Series pumps. Each fluid chamber has an inlet ball and an outlet ball, and they are what make the pump one way: the diaphragm creates suction and pressure, and the balls decide which direction the fluid is allowed to travel.
The usual failure is not dramatic. Output falls off gradually, the pump starts taking longer to prime, and the operator turns the air pressure up to compensate - which loads the diaphragms harder and shortens their life as well. Rolling the old balls on a flat surface will usually show the flat spot straight away.
Key Features
- Genuine Yamada replacement check valve ball
- Material: Buna-N (NBR)
- Fits DP-15 and NDP-15 Series pumps
- 4 per pump - two on the suction side and two on the discharge side
- Restores check valve sealing and suction lift
- Replace balls and valve seats as a matched set
Applications
- DP-15 and NDP-15 Series pumps
- Restoring lost flow and slow priming
- Rebuilding a wet end after abrasive service
- Scheduled liquid end overhauls
- Replacing balls worn flat or undersize
- Marine, industrial and chemical transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 771525
- Part Type: Check Valve Ball
- Material: Buna-N (NBR)
- Fits: DP-15 and NDP-15 Series pumps
- Quantity Used: 4 per pump
- Series Port Size: 1/2 in on the NDP-15 Series
- Condition: New
Frequently Asked Questions
Q: Can I run a different ball material than the pump was built with?
You can, provided it is compatible with the fluid and rated for the temperature. Weight matters too, since a ball that is too light is slow to reseat at high cycle rates.
Q: Should all four balls be changed together?
Yes. They have done the same work, and a mixed set of new and worn balls gives uneven check action between the two chambers.
Q: Does ball wear damage anything else?
Indirectly. Operators compensate for the lost output with more air pressure, and the extra pressure is taken by the diaphragms and the center rod.
Q: How do I tell if a ball is worn?
Roll it on a flat surface and look along the edge. A worn ball wobbles or shows a dull flat band where it has been seating, and it will usually be visibly smaller than a new one when the two are held together.
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 check valve ball.
CLRMarine
