Yamada 711707 Valve Seat, stainless steel for NDP-25
The Yamada 711707 is the genuine replacement valve seat specified for NDP-25 Series pumps with stainless steel wet ends. Together with the ball above it, it forms one of the four check valves that give the pump its direction of flow.
The material of the seat has to suit the duty. Aluminum suits general transfer, stainless steel suits abrasive and aggressive product, and polypropylene and Kynar suit chemical service where metal is not an option. Keep the seat, the ball and the wet end compatible with each other and with the fluid.
Key Features
- Genuine Yamada replacement valve seat
- Material: stainless steel
- Fits NDP-25 Series pumps with stainless steel wet ends
- 4 per pump in a standard pump build
- Restores check valve sealing and suction lift
- Replace together with the matching check balls
Applications
- NDP-25 Series pumps with stainless steel wet ends
- Liquid end rebuilds after abrasive service
- Restoring flow lost to a grooved or bruised seat
- Scheduled wet end overhauls
- Repairing a pump that drains back when stopped
- Marine, industrial and chemical transfer duty
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 711707
- Part Type: Valve Seat
- Material: Stainless steel
- Fits: NDP-25 Series pumps with stainless steel wet ends
- Quantity Used: 4 per pump
- Series Port Size: 1 in on the NDP-25 Series
- Condition: New
Frequently Asked Questions
Q: Can I mix seat materials in one pump?
Do not. All four check valves should be the same material so they wear at the same rate and share the duty evenly.
Q: How do I inspect a valve seat?
Take it out and look across the seating face under a good light. A serviceable seat shows an even, continuous witness line where the ball sits. A groove, a dent or a break in that line means it will leak.
Q: Can a valve seat be lapped instead of replaced?
On a metal seat you can improve a lightly marked face, but removing material changes where the ball sits and how much lift it has. On plastic seats it is not practical at all.
Q: Which way round does the seat fit?
Each seat is handed for flow, with the ball landing on the machined face. Fitting one upside down gives a pump that runs but delivers almost nothing, so note the orientation before removing the old ones.
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 valve seat.
CLRMarine
