- Switch off the breaker and take out the fuse.
- Place MEN AT WORK board.
- Isolate the pump by closing suction and discharge valve.
- Open the vent valve to check that valves are holding.
- Motor electrical connections to be removed.
- Mark on couplings with permanent marker.
- Take out the coupling bolts of pump and motor.
- Disconnect suction and discharge flanges
- Remove foundation bolts.
- The shims below pump should be removed and placed acc to their location so that they can be placed back in correct position.
- Suction and discharge line to be covered with clothes.
- Take pump to workshop.
- Take the coupling out by bearing puller.
- Remove key of coupling
- Remove end covers on both side.
- Remove mechanical seal.
- Remove the locking nut on other end and the bearing.
- Take out the gear shaft along with bush.
- Remove the relief valve cap at top and take out relief valve spring and seat.
- Clean all parts and carry out inspection.
- Check gear for wear, backlash, damage.
- Bearing to be check for unsual noise and damage.
- Check bush and shaft clearance.
- Check gear shaft for grooving mainly where seal sits.
- Check clearance between casing and gear.
- Check relief spring tension.
- If everything is ok then start boxing back with new gaskets for end covers. Gaskets to be made of paper mostly.
- Bearing to be renewed.
- Mechanical seal to be renewed.
- Box back the pump.
- When placing the pump back on place. First put the shims on correct place.
- Then the coupling Bolts and check the alignment.
- If alignment is ok then tighten the foundation bolts or else adjust the shims.
- Tight the suction and discharge bolts and nuts.
- Open the suction valve and purge the pump.
- Open the discharge valve.
- Make electrical connections and put fuse back.
- Switch ON the breaker.
- Start and stop the pump to check the direction of rotation.
- If ok then pump can be put in operation.
6 responses to “Gear Pump Overhaul”
In a gear pump there are only bushes in the casings. There are no bearings. Before you start pump, fill it up with medium used to avoid dry-running.
There are bearings also in some pumps while in some there is no bearing.
A bush is a bearing
No. In small gear pumps there is a small bearing on the non driving end. Although it’s not necessary to have bearing. But since I have overhauled many and found both type so it’s better to say bearing is there
A bush is never a bearing
Hello my name’s Calvince a student in Kenya at Technical University of Mombasa pursuing degree in marine engineering.I’m asking,,”What are the key components of gear pump that must be paid attention to during overhaul” thank u.