Yamada 611231 Bolt for NDP-50
The Yamada 611231 is the genuine replacement bolt specified for NDP-50 Series pumps. It is the correct grade and length for the joint it belongs to.
Fasteners in a pump like this are replaced for three reasons: corrosion has taken the head or the thread, the thread has been stretched by overtightening, or one has simply gone missing during a previous strip down. Any of them leaves the joint clamping unevenly, and an uneven clamp around a diaphragm bead or a manifold face is what turns a sealed joint into a weeping one.
Key Features
- Genuine Yamada replacement bolt
- Fits NDP-50 Series pumps
- 4 per pump in the assembly that uses it
- Correct grade, length and thread for the joint
- Keeps clamping load even around elastomer sealed faces
- Direct replacement for corroded, stretched or missing hardware
Applications
- NDP-50 Series pumps
- Pump rebuilds and scheduled overhauls
- Replacing corroded or seized hardware
- Making up a complete set after a strip down
- Marine installations where corrosion takes fasteners first
- Industrial and transfer pump service
Specifications
- Brand: Yamada
- Manufacturer: Yamada America
- Manufacturer Part Number: 611231
- Part Type: Bolt
- Fits: NDP-50 Series pumps
- Quantity Used: 4 per pump
- Series Port Size: 2 in on the NDP-50 Series
- Condition: New
Frequently Asked Questions
Q: What torque should I use?
The factory figure for that joint, applied in sequence across the joint rather than around it. Even clamping is what keeps the sealed faces sealed.
Q: Do I need to replace all of them at once?
If several are corroded, replace the set. A mix of new and tired fasteners gives uneven clamping, and the old ones will need doing at the next service anyway.
Q: Should I use thread lubricant?
An anti seize compound on the threads is normal practice on this kind of assembly, particularly in marine service where it is what allows the joint to be opened again.
Q: What happens if one is left loose?
The clamping load is uneven, the joint weeps at that point, and the remaining fasteners carry more cyclic load than they were meant to.
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 bolt.
CLRMarine
