Cracked, corroded or worn pump casings, volutes and end covers repaired and machined back to size in Durban. CRS Group has repaired cast iron pump housings for refineries, sugar mills, municipal plant and mines since 1977, on the bench or in position on site.
When a pump housing is worth repairing
Pump casings fail in predictable ways. Cavitation and abrasive slurry eat the volute. Corrosion thins the water passages. Frost or water hammer cracks the casing. Wear rings and bearing landings go oversize. Bolt flanges crack when a pump is pulled and refitted too many times. On a standard small pump, a new casing is often the quickest answer. On a large, old or imported pump the picture changes: the casing may be obsolete, a replacement may be months away, and the pump may be holding up a process that costs far more per day than the repair.
CRS Group repairs cast iron pump housings for exactly those cases. The work combines three capabilities under one roof: cold metal stitching for cracks, specialised welding for rebuilding worn or corroded sections, and general engineering to machine faces, bores and landings back to drawing.
Crack repair by metal stitching
A cracked pump casing is a classic metal stitching job. The repair is done cold: interlocking nickel alloy keys are fitted across the crack to pull it together, then a line of overlapping pins seals it. No heat goes into the casting, so there is no distortion of the machined faces and no risk of the crack running further as a weld cools. The result is a pressure-tight repair that can be dressed flush and, where needed, machined over.
Because stitching needs no flame, it can be done in situ on pumps that are too large or too awkward to remove, including in hazardous areas where hot work is restricted. Suction and discharge flanges, volute casings, split-case halves, end covers and bearing housings are all regularly repaired this way.
Rebuilding worn and corroded casings
Where metal has been lost rather than cracked, CRS Group welds the section up and machines it back. Cast iron, bronze and stainless steel are all handled in-house. Typical work includes rebuilding eroded volutes and cut-waters, restoring wear ring seats and bearing landings to size, re-facing gasket and flange faces, re-sleeving bores, and repairing or re-tapping stripped bolt holes. The machine shop that does the finishing is the same one that does CRS Group’s engine reconditioning and component manufacture, so tolerances are held to what the pump needs, not to what a general welder can manage.
Impellers too
A casing repair is often paired with impeller work. CRS Group repairs and machines existing impellers and manufactures new ones in cast iron, bronze and stainless steel, including obsolete patterns reverse-engineered from a worn sample. Repairing the housing and the impeller together gets the pump back to its original clearances rather than fixing one half of a worn pair.
Pressure testing is carried out in the workshop where the casing allows it. Some components are sent to an outside NDT specialist, and repairs done in position on site cannot always be pressure tested. CRS Group will tell you which applies before the job starts.
Who CRS Group does this work for
- Petrochemical and refinery plant, including repeat pump housing and impeller work for a Durban refinery
- Sugar mills and agricultural processing across KwaZulu-Natal
- Mining and quarrying slurry and dewatering pumps
- Municipal water and wastewater pump stations
- Marine, shipping and port equipment
- General manufacturing and process plant
Work is quoted individually on the damage, the material, the size of the casing and whether it is repaired in the Mayville workshop or on site. Being Durban-based means no overseas contractor travel, accommodation or standby charges before the job starts, and a realistic lead time given at quote stage.
Related services
- Metal stitching for cracked cast iron
- On-site metal stitching across KZN and nationwide
- Specialised welding in cast iron, steel, bronze and aluminium
- General engineering: bearing housings, bores, faces and landings
- Component manufacture for impellers and obsolete parts
Get a quote on a pump housing
Send photos, the pump make and size, and a note on the damage. CRS Group will recommend a method and give a price and lead time.
Phone: 031 209 3168
WhatsApp: 084 511 5929
Email: info@crsgroup.co.za
Workshop: 16 Saxon Avenue, Mayville, Durban, 4058