No matter the pump, inspection is performed and an inspection report is documented. The individual parts of the pump are all sandblasted, and the repair process begins. The specifics of the procedure depends on the building material of the pump. Repairs are available for the assembly, body, heads, cones, shaft, or rotor depending on the need.
Pump assembly repair procedure is the same for all pumps. The assembly is examined to confirm that the correct parts had been used to construct the pump, including but not limited to bearings, lip seals, and check valves. New replacements are purchased and assembled according to OEM specifications.
For all pumps, the body end fittings and compression areas are examined to confirm proper sizing. For cast iron, the fittings are pre-machined to accept stainless steel shroud rings. The rings are welded and the fittings are machined to OEM dimensions. The compression area is welded with nickel wire when necessary and machined to OEM specifications. For stainless steel, the body internals are pre-machined to accept a stainless steel plate, rolled to size, and shroud fit rings. The rings are welded in place, the plate is welded to the internals, and the body is machined to OEM dimensions.
All pump heads are checked in its critical areas for proper sizing and concentricity. Bearing bores and stuffing boxes are sleeved and machined to size. Worn head faces are welded with nickel wire and machined to OEM dimensions. For stainless steel, the head faces are pre-machined to accept the stainless steel plate that is rolled to fit the face. Applicable areas are welded, and the rest is attached with stainless steel countersunk screws.
All pump cone repair begins with machining the cone taper outer diameter of the cone tapers. For cast iron, the outer diameter is machined to alleviate wear and eccentricity. For stainless steel, it is machined to accept a quarter-inch thick stainless steel skin. The skin is welded onto the worn cone, the porting is cut, and it is machined to size. All pump cone bolting flanges are machined as needed to their true mounting surfaces.
Pump shaft repair begins with assessing wear in the bearing journals, lip seals, and packing areas. If wear is significant, the areas are sleeved and machined to size.
Pump rotor repair varies drastically depending on the material. For cast iron, blade tip erosion is repaired first. For stainless steel clad pumps, the outer diameter of the rotor shrouds are machined for stainless steel rings. The rings are welded on and machined according to OEM dimensions, and then the rotor vane tips and buckets are repaired. In all pumps, rotor tapers are pre-machined for nickel welding as a method of dimension correction and machined according to OEM dimensions. The shaft is reinstalled into the rotor, and the shaft assembly is properly aligned so that all fittings are concentric. The repair ends with rotor balancing when necessary.
NES Company boasts a no-shortcuts policy: no epoxy or metallizing spray is used to build dimension. In addition to this, we offer a 98% performance warranty against manufacturer’s defects.