Pump-Motor Foundation

A solid foundation to help absorb any abnormal loads is important. It is suggested the pump and motor be mounted together on a separate integral base before being plumbed into the system. Do not attach pump mounted base to the floor since expansion and contraction caused by hot and cold cycles cause plumbing to draw and the base to move.

Direct versus Indirect Drive

Most pumps are driven by an indirect drive by V-belts. This is a more economical installation, as opposed to a gear box, and, in case the pump stops, the belts will usually break, preventing a more costly breakage; and the indirect drive gives more flexibility in pump mounting. The major disadvantage of the indirect drive is size since reducing the pump speed often requires a large pulley. Centrifugal pumps are nearly always driven by a direct drive since they turn at a much faster speed. Always provide suitable belt or coupling guards for protection.

Proper Pump Installation

Motor Alignment-Some pumps require the use of an outboard bearing near the shaft end. Exact centering of the shaft in relation to the pump housing is of extreme importance. It may be necessary to use shim material to insure correct centering. In the case of the indirect drive, drive pulleys of the pump and motor must be aligned properly. For the direct drive, the same proper alignment applies to coupling halves. The following examples are given for proper alignment. Always turn the pump over by hand after mounting and plumbing to make sure there are no tight spots. Some pump manufacturers recommend removing the head of the pump and checking between internal members and the pump casing for proper clearances with a feeler gauge.

Failure to properly align the pump and its motor will result in increased wear and maintenance for the unit.

Pump Location

Always locate the pump as close to the source of the liquid to be pumped as possible. Remember a pump can push material easier than it can suck it. Also, locate the pump so it is accessible for maintenance and repair. Being able to remove the pump’s internal members without removing the pump from the base is often very handy. If at all possible be sure a positive suction head exists, that is, the liquid level of the tank is always above the suction port of the pump.

Pump Heating

Can be accomplished by hot water, oil or low pressure steam if the pump is jacketed, or by electrical trace lines. Insulation around the pump helps hold the heat. Means should be provided to regulate the amount of heat to the pump. If electrical trace lines are used, fill the pump jacket(s) 80 to 90% full of heating oil.


Most pump manufacturers will normally specify a basket strainer. They are, in fact, rarely used in the field because a strainer fine enough to protect the pump needs a very large surface area and is very expensive. They also require isolation valves for cleaning.

System Plumbing

General comments:

  • Plan the system to provide maximum flexibility and utilization.
  • Plan for future expansion.
  • Be sure suction piping is at least the same size as the suction port of the pump or larger for long suction lines and more viscous materials.
  • Keep suction piping as short as possible.
  • Use of a swedge or bell reducer one size larger than the suction line is recommended at the tank outlet. Also, the use of an elbow inside the tank will permit sucking near the bottom of the tank and still leave scum buildup inside.
  • Always put a length of return or recirculate line inside tank to permit better tank circulation which may be required.
  • Design piping systems to allow for the transfer of materials from one tank to another. This system may also be used to mix or re-circulate the product.

BEST PRACTICE: This should only be done on a limited basis. A continued need for mixing should be addressed by the use of a side entry mixer.

  • Never use the same pump for anionic and cationic emulsions, unless thoroughly cleaned and flushed.
  • Always turn the pump by hand after final installation to make sure the plumbing has not caused any bind.
  • Minimize all tees, elbows, and other restrictions in the suction line. Use of full port valving is recommended.
  • Provide plumbing to accommodate a vacuum or pressure gauge in the suction and discharge lines.
  • Use of direct flame heat on any part of the plumbing or pump should be done with extreme caution.
  • If a positive displacement pump is used, it is suggested to take advantage of its reversing ability to clean lines at end of loading. When installing positive displacement pumps, you should also install some type of pressure release system.
  • Use of unions, flanges, and spools will permit rapid removal of components for maintenance.