How to Maintain Gear Pumps

Gear pumps are rotary pumps that use two meshing cogs to force out liquids with both low to high viscosities. They are usually used in hydraulic machinery and in chemical installations that necessitate pumping of fluids with various densities. 

How Gear Pumps Operate

Gear pumps are simple, durable and inexpensive pumps that are suitable for pressures below 20 MPa (3,000 psi). These pumps fall under positive displacement, which means that they pump a steady amount of fluid for each cycle. The two gears derive liquid into the enclosed inlet valve during the suction stroke. The liquid is then trapped by the gear teeth and forced out to the outlet during the discharge stroke.

For lubrication, the gear pump utilises a small amount of oil that comes from the forced side of the gears that flows through the hydrodynamic bearings and expels the same oil to the part of the gears with low pressure. Disastrous breakdown rarely occurs since the cogs gradually wear down the case and reduce the volume efficiency of the pump slowly.

Maintenance of Gear Pumps

To ensure that the gear pumps work efficiently, occasional maintenance should be observed. Here are some pointers when keeping these water pumps in good working condition:

• Gear pumps necessitate a strong installation. You can include a pressure reducing valve or PRV to protect them from overpressure.

• An ample supply of clean liquid is also indispensable.

• The outboard bearings, if present, should be appropriately lubricated.

• It is better to use pumps that do not use mechanical seals for these have a separate set of problems.

• Unlubricated gear teeth will chafe each other and may cause corrosion of the cogs. The best solution to this problem is to install a flow switch that automatically turns off the pump if there is no flow.

Now, here are the steps in maintaining your gear pumps:

1. Take out the cover of the gear pump using a screw driver or other tools, as instructed by the pump manual.

2. Check for signs of wear and tear on the tips of the gear teeth. A new pump would hardly allow a thin sheet of wrapping paper to be inserted between the gear teeth and the chamber wall (0.005 to 0.007 inches). A greater clearance means that the cogs have been rubbing each other for a period of time.

3. Assess the bearings for signs of scuffing, which usually make the bearings appear egg-shaped. If gears are damaged, replacement is needed.

4. Scrutinise the pin that supports the gears to the shaft and check if it is damaged for it may result to pump failure. If the pin is sheared off, then it should be replaced as soon as possible.

5. Check the pump case for lumps for these may be signs of overpressure and may allow liquids to leak during the pumping process.

So, if you are looking for efficient submersible pumps, water pumps and other pumps in Australia, then you should hire reliable pump providers. 

To learn more, contact Pump Solutions Australasia or visit their website at http://pumpsolutions.com.au/.