Pump Installation and Alignment

A poor installation can negate any alignment attempts, leading to premature pump failure. All base-mounted pumps require alignment after installation onsite because components are malleable and can be stressed or twisted by pipe weight, tension, or soft foot issues. Alignment is crucial to minimize friction on bearings, as misalignment increases friction and heat, leading to component failure.

The first step is a rough alignment to ensure the pump is in a neutral position with no tension. Loosen all bolts, remove the coupler, and visually inspect alignment. The video contrasts old Suureflex and new Duraflex couplers, highlighting the Duraflex's ability to visually show misalignment. It's recommended to leave the hubs loose until final alignment to identify tension issues during installation.

Improper installation, such as cranking down bolts on an uneven housekeeping pad, can twist the base and put the pump under tension, leading to misalignment and vibration. The video demonstrates how tightening bolts on an artificially uneven surface drastically alters coupler alignment. Shims should be used under the base to maintain a neutral position and avoid tension.

Soft foot occurs when one attachment point requires more shimming than others, causing twisting. To check for soft foot, loosen each bolt one at a time and observe if shims move. Laser alignment tools often have functions to identify soft foot. Correct soft foot using graduated, stainless steel shims of appropriate size (B, C, or D depending on motor horsepower). Avoid plastic, paper, wood, brass, bronze, or copper shims.

Verify that the pump and motor can move freely to achieve alignment without force. Do not use crowbars or ratchet straps as this introduces tension, which vibration will eventually release, causing misalignment. When tightening bolts, use a crossing pattern, applying half torque first, then full torque. For 3/8-inch, grade 5 bolts, typical torque is 12-15 foot-pounds; use a torque wrench to develop muscle memory.

Properly tightening the bearing frame foot involves loosening all three bolts, snugging them up to pull the bracket down to the frame, tightening the main bolt, then loosening and re-tightening the other bolts. This sequence prevents tension on the bracket and misalignment of the pump's nose.

After initial setup, prevent overhung weight from piping. Cast iron is malleable, and excessive weight can bend the casing, misaligning internal components and seals. Use suction diffuser stands to support the diffuser's weight, not pipe weight. Ensure pipe connections are neutral by checking for a 0.005-inch gap with a feeler gauge. Flex connectors that are bowed or twisted indicate pipe tension. Ensure electrical conduit does not pull on the motor to avoid misalignment. All installation steps should be completed before final alignment.

Grouting the base is the final step, creating a solid mass that absorbs vibration and maintains alignment. When adjusting pumps or motors, never hit the shafts or couplers with a hammer, as this damages bearings. Instead, use pry bars against the base or levers under the feet. If direct impact is necessary, hit the feet with a softer material drift, such as brass.

Close-coupled pumps, lacking a base, are also susceptible to overhung pipe weight. Support all piping and use supports under suction diffusers to prevent casing deformation and misalignment of internal components, ensuring long-term performance.

When reassembling the coupler, tighten the set screw until it 'digs in' to prevent wear on the motor and pump shafts. Install coupler hubs with keyways opposite each other for better balance. Use hand tools for the zinc bolts of the flexible element, tightening them to snug plus an eighth of a turn to avoid shearing. Ensure at least a 3/16-inch gap between shafts to allow for thermal expansion during operation. For pumps stored before operation, rotate them weekly to prevent rust lock-up and flat spots on motor bearings.