Weinman 135641 Casing Kit for Size 4Q, 375 and 575 Series
The Weinman 135641 is the genuine Weinman casing kit for size 4Q pumps in the 375 and 575 Series back pull out range. The casing is the pressure boundary and the volute: it holds the liquid in, carries the suction and discharge connections, and slows the flow leaving the impeller so that velocity becomes discharge pressure.
Corrosion is the quiet one. It thins the casting from the inside where nobody can see it, and the first sign is a weep at a flange or a pinhole under load. Once a pressure boundary is compromised it is not a candidate for patching, particularly on a pump feeding a building system.
Casings are size specific. The Weinman range covers many duty points on different castings, and the size designation combines the discharge connection with the casing group letter - size 4Q here. Check the nameplate and the port sizes against your pipework before ordering.
Key Features
- Genuine Weinman factory casing kit for size 4Q
- Supplied with the sealing and fastening hardware for the joint
- Original port sizes, bolt pattern and volute geometry
- Restores the pressure boundary and the impeller clearance
- Fits Weinman 375 close coupled and 575 frame mounted pumps
- Back pull out design keeps the pipework undisturbed
Applications
- Weinman 375 and 575 Series back pull out pump repair
- Replacing a casing cracked by freezing or impact
- Repairing corrosion or erosion inside the volute
- Recovering duty lost to a worn volute passage
- HVAC, hot water, commercial building and municipal systems
- Industrial, marine and dockside installations
Specifications
- Brand: Weinman
- Manufacturer: Crane Pumps and Systems
- Manufacturer Part Number: 135641
- Part Type: Casing kit
- Size: size 4Q
- Fits: Weinman 375 and 575 Series back pull out pumps
- Condition: New
Frequently Asked Questions
Q: How can I tell the casing is worn rather than the impeller?
Look for a polished or grooved band in the passage opposite the impeller tips, and measure the clearance at several points around the circumference. Wear that has opened the gap evenly all the way round points at the casing.
Q: Does a new casing need machining before it goes on?
No. It comes finished to the original Weinman dimensions. What does need attention is the adapter mating face, which should be cleaned back to bare metal so the new seal has a true surface to work against.
Q: What does back pull out actually mean for this job?
The rotating element and the adapter withdraw rearward with the motor or bearing frame, leaving the casing bolted to the suction and discharge pipework. It is why most Weinman repairs need no pipe fitting at all - and why replacing the casing is the exception rather than the rule.
Q: Can a cracked casing be welded instead?
Cast iron can be welded with preheat, the right rod and controlled cooling, but you end up with a repaired pressure boundary carrying residual stress. On a pump of this size the economics rarely favour it.
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 casing kit before you order.
CLRMarine
