Horizontal Pumps

The discharge head is the vertical distance from the centerline of the pump (this would be the shaft on a horizontal pump) to the level in the discharge vessel. 

Labyrinth seals work best when the pump is running. Centrifugal force favors the labyrinth seal s action. Earlier models were only specified for horizontal pump shafts. Later models are designed for both horizontal and vertical pump shafts and effectively perform their function whether the pump is running or off... 

In-house correlation of pumps should be made using gpm vs. cost with head as a parameter. These should result in step functions, since one size pump with different impellers can serve several flow rates and heads. Different correlations should be made for each type of pump. The price of a vertical multistage pump may be quite different from a horizontal splitcase multistage pump. A sump pump with a 15-ft drive shaft would cost more than a single-stage horizontal pump with the same gpm and head. 

The proper design of sumps for the use of vertical lift pumps or horizontal pumps taking suction from a sump is important to good suction conditions at the pump [2, 3,14]. 

A suction bell on the inlet of a vertical pump (or the inlet pipe of the suction side of a horizontal pump) is not necessary as far as pump or sump operation is concerned. If a bell is omitted, the entrance losses due to flow will be higher ith only a straight pipe, and this must be considered in pump operation. An economic comparison vsill help decide the value of the bell. Strainers should not be placed on suction bells unless this is the only arrangement. Inlet water should be screened with trash racks, bars and screens to keep the sump free of debris. 

Horizontal pumps can be classified according as end suction, side suction, bottom suction, and top suction. 

For onshore facilities, water may be supplied from local public water mains, storage tanks, lakes and rivers. In these cases a conventional horizontal pump is used. The preferred design for onshore fire water pumps is a horizontal centrifugal type with a relatively flat performance curve (i.e., pressure versus quantity). The discharge pressure is determined by the minimum residual pressure required at the most remote location of the facility flowing its highest practical demand with allowances added for piping friction losses. 

Centerline supported pump casings shall be used for horizontal pumps. 

Steel and alloy steel horizontal pumps, and their baseplates, and vertically suspended pumps shall be designed for satisfactory performance when subjected to the forces and moments in Table 2-1A (2-IB). For horizontal pumps, two effects of nozzle loads are considered Distortion of the pump casing (see 2.2.8) and misalignment of the pump and driver shafts (see 3.3.5). 

Figure 2-4—Coordinate System for the Forces and Moments in Table 2.1 A (2.1 B) Horizontal Pumps with Side Suction and Side Discharge Nozzles...

Figure 2-8A—Locations for Taking Vibration Readings on Horizontal Pumps...

Single piece drain rim or drain pan baseplates shall be fnmished for horizontal pumps. The rim or pan of the baseplate shall be sloped at least 1 120 toward the pnmp end, where a tapped drain opening at least 2 NFS shall be located to effect complete drainage. 

Vertical shaft, turbine type pumps have their impellers submerged, hence, they are ideal for conditions where a suction lift would be required for horizontal pumps. The second impeller from the bottom of the pump bowl assembly should be submerged below the lowest pumping water level. The submergence should be increased by 1 ft (0.30 m) for every 1,000 ft (305 m) of elevation above sea level. These pumps should provide 150% of the rated capacity... 

The horizontal pumps are available for capacities up to 900 m /h (4000 gahmin) the vertical in-line pumps, for capacities up to 320 m /h (1400 gahmin). Both horizontal and vertical in-line pumps are available for heads up to 120 m (400 ft). The intent of each ANSI specification is that pumps from all vendors for a given nominal capacity and total dynamic head at a given rotative speed shall be dimensionally interchangeable with respect to mounting, size, and location of suction and discharge nozzles, input shaft, base plate, and foundation bolts. 

Unless otherwise specified, the datum elevation shall be the shaft centreline for horizontal pumps, the suction nozzle centreline for vertical in-line pumps, and the top of the foundation for vertically-suspended pumps. 

Centreline supported pump casings shall be used for all horizontal pumps except as allowed in 8.2.1.2. 

Figure 24— Co-ordinate system for the forces and moments in Table 4— Horizontal pumps with top...

Figure 27 — Locations for taking vibration readings on horizontal pumps...

Figure29 — Vibration limits for horizontal pumps running above 3 600 r/min or absorbing more than...

Pumps can be either the horizontal or the vertical type. The selection of pump type depends on the water basin, which can be underground or aboveground. An economic evaluation should be made to ascertain which is the more. convenient solution—aboveground basins with horizontal pumps or underground basins with vertical pumps. 

Pump installation is an important point to be carefully considered. In the case of vertical pumps, pump submergence should comply with the vendor s specifications. In the case of horizontal pumps, the designer should control the following points ... 

Motor, squirrel cage, induction, 440 volts Motor, squirrel cage, induction, 440 volts Pump, centrifugal, horizontal Pump, centrifugal, horizontal Tower, c.s. 

Determine whether a vertical or horizontal pump is more desirable. From the standpoint of floor space occupied, required NPSF1, priming, and flexibility in changing the pump use, vertical pumps may be preferable to horizontal designs in some installations. But where headroom, corrosion, abrasion, and ease of maintenance are important factors, horizontal pumps may be preferable. 

Application of Bernoulli s equation to a simple horizontal pump or compressor with equal-sized inlet and outlet pipes leads to... 

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Horizontal pumps Single with external flush Extended seal life Low seal cost Pump can be run dry if flow is lost Seal water piping required Caustic and water will intermix Freeze protection of seal water piping may be required... 

Vertical pumps Sealless siin style No mechanical seal No seal liquid required No fieeze protection of seal liquid piping More expensive than horizontal pumps with mechanical seals Bearing flush and associated maintenance required on some models with long shafts Poor access for maintenance Motor not rigidly mounted on foundation... 

In case of horizontal pumps, it is preferable to have suction from two sides (balanced type). It should not become necessary to dismantle the suction and/or discharge pipelines for maintenance work on the pump... 

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