The SC is a mid-range, single-stage, cone-ported liquid ring pump used for paper machine vacuum, process vacuum and gas compression across most of the industries we serve. It is offered in single-cone and dual-cone configurations. In a single-cone pump one cone carries the inlet and discharge porting; in a dual-cone pump a cone at each end of the rotor shares the porting, which raises the flow a given frame can handle.

What fails on an SC pump. The rotor-to-cone clearance controls capacity, and it opens up from abrasive seal water, scale that scores the cone face, and rubs during hard starts. Seal water carrying hardness or process solids scales the rotor and cone and unbalances the rotor. Cast iron corrosion pits the cone face and thins the body at the water line. Bearings and shafts fail from contamination and from water past worn packing.

How we rebuild it. We measure the rotor-to-cone clearance and cone runout before repair and report the cause of failure. Cones are remachined true to the shaft centerline or manufactured new. Rotors are restored at the cone bore and balanced. Corroded cast iron is welded and remachined, and where corrosion is chronic we clad the water-contact surfaces in 304L or 316L stainless. Shafts, sleeves, bearings and seals are repaired or replaced to OEM specification, and the pump is assembled to original OEM tolerances with every clearance double-checked.

Exchange and replacement. We regularly stock rebuilt SC2 through SC7 exchange units. When an SC pump is beyond economic repair, Precise Mechanical manufactures new SC-compatible pumps in single-cone and dual-cone configurations that are drop-in, requiring minimal or no piping or baseplate modification.

The 2BE is a single-stage liquid ring pump with flat port plates rather than cones. The rotor runs between two port plates that carry the inlet and discharge openings, and the axial clearance between rotor and plates sets the pump's capacity. 2BE pumps are common in paper mills, chemical and petrochemical plants, power generation and mining, and are frequently used as compressors as well as vacuum pumps.

What fails on a 2BE pump. Port plate wear and scoring is the primary failure. Solids in the seal water lap the plate faces, scale on the rotor rubs them, and once the axial clearance opens up, air recirculates from discharge to inlet and capacity falls. Rotor blade erosion from cavitation, corrosion of cast iron bodies and plates, shaft wear at the sleeves, and bearing and seal failure follow the same pattern as other Nash pumps.

How we rebuild it. Port plates are resurfaced or manufactured new and set square to the shaft. Rotors are restored at the faces and balanced. Bodies, heads and plates in cast iron are welded and remachined, or clad in 304L or 316L stainless where the service is corrosive. The pump is assembled to OEM axial clearance and every measurement is double-checked before the heads go on.

Replacement. Precise Mechanical manufactures new drop-in replacements for the 2BE1 and 2BE3 single-stage, built to the original mounting and connection layout, requiring minimal or no piping or baseplate modification. Ask about exchange availability for 2BE pumps.

The older Nash H and L series cone-ported pumps are still running in many plants, and we rebuild them and regularly stock rebuilt L3, H4 and H5 exchange units. When a cone, rotor or head is no longer available from the OEM, we reverse engineer it from your pump and manufacture it in our shop.

The Nash XL series, from the XL80 through the XL500, is another single-stage cone-ported line we rebuild and stock as exchange units, commonly for process vacuum and vapor recovery service.

For the HC series, Precise Mechanical manufactures new drop-in replacement pumps in addition to rebuilding the originals. Call with your nameplate data and we will confirm the match.