Figure 6-27. - Principle of operation of an ejector-type jet pump.

into the chamber and out through the discharge line. Thus the pumping action is established.

INSTALLATION OF PUMPS

From time to time, you will be installing prime movers, pumps, and air compressors. The secret of success in operating prime movers, pumps, and air compressors is their proper installation. That puts the success of their operation directly in your hands. If you do your job right and the equipment is properly installed, it should perform satisfactorily for a long time. Of course, proper care and maintenance are also essential for continued efficient operation; however, even with the most perfect care and maintenance, you will find it difficult or impossible to overcome faulty installation.

Since the procedures for installing prime movers, pumps, and air compressors are almost the same, only the basic steps of pump installation are discussed in this chapter. Remember that pumps, especially the centrifugal type, are built in many designs and for different purposes. Study the manufacturer's instruction manual for the equipment you are installing. Where specific directions or requirements are furnished, follow them.

When you receive a pump unit from supply, there are a few points to check. First, ensure it is the correct pump for the job by checking the nameplate data against that of the bill of material. Next, check the unit to ensure there are no missing or loose parts. If the unit has a preservative covering (exterior or interior), make certain it is removed before being installed.

When pumps are to be installed, the locations usually are determined in advance by higher authority and indicated on blueprints or sketches. However, you may have to decide where to put a pump. In most cases, place the pump as close as possible to the source of supply of water or other liquid, so the suction pipe is short and direct and the suction lift is comparatively low. With high-temperature liquids, a suction head is necessary. Place the pump where it can be readily inspected during operation, and see that headroom (a trap or ceiling opening) is there for the use of a crane, a hoist, or a tackle. If possible, select a dry place to protect the pump from the weather.

The foundation of a pump must be strong enough to absorb vibration and also to serve as a rigid support for the pump baseplate. A concrete foundation or a solid base is best. Foundation J-bolts are embedded in the concrete foundation according to a blueprint or a template. The bolts should be longer than needed (3/4 to 1 inch) to allow for shimming up the pump to make it level and for grouting under the pump base. A pipe sleeve, about 2 1/2 times the diameter of the bolt, allows for final positioning. If the bolt shown in figure 6-28 were 1 inch in diameter, a 2 1/2-inch pipe sleeve should be used. A small pump is normally aligned and the two major parts bolted together before leaving the factory. The parts normally do not require alignment after the pump has been set on the foundation. Be careful that you do not spring them out of alignment. Level the pump properly and secure it to the foundation. In setting the pump, you need a spirit level; place the level on the machined surfaces in two directions. To level, you may have to remove the top casing or bearing cover. If a large pump is shipped in sections, you have to align the water ends with the power ends after they have been placed on the foundation.

Figure 6-28. - Pipe sleeve and foundation bolt.