1. Horizontal
Benefits
1. Easier to install and maintain because casing can remain in pipeline for back-pull-out.
can have good NPSHav with flooded suction.
2. It is suitable for almost all indoor applications due to its low headroom requirements.
3. For high and very high temperatures, can be offered in centerline mounting.
4. Better accepted standard because of tradition, cost, & availability. International standards gives mounting dimensions for pump interchangeability.
Easier for handling and transportation, compared to vertical pumps
Disadvantages
1. Requires priming for starting of a pump.
2. Occupies more floor space compared to vertical / submersible pumps.
3. Shaft sealing is critical in case of hazardous, flammable or explosive liquids.
4. Coupling alignment is important.
2. Vertical (Extended Shaft)
Benefits
1. No priming required due to submerged casing.
2. Ease of motor alignment.
3. Less mounting space is required.
4. Less worry of shaft sealing, compared to horizontal pumps.
5. Less noise compared to horizonal pumps.
6. Suction pipeline and valves are eliminated, hence possibly saving in cost.
7. Can be inside tank or mounted outside tank.
8. Double delivery pumps can be ideal solution for high temperature applications.
9. Double delivery pumps balances radial thrust, hence higher life of pump.
10. Ideal for pumping hazardous and flammable liquids.
Disadvantages
1. Requires skills for installation, operations and maintenance.
2. Alignment of a pump is very important.
3. Relatively more wear parts, hence more spares compared to horizontal pumps.
4. Full pump, including delivery pipe and column pipe are required in compatible metallurgy.
5. Costiler than horizontal pump.
6. Requires sufficient head room for installation and lifting of the pump.
7. Ignoring increased clearances in bush / sleeve due to wear can damage the pump parts.
3. Submersible
Benefits
1. Significant simplification of civil structure, elimination of dry pit for pumping.
2. Flood-proof pumping using submersible motor.
3. Substantial reduction of civil construction cost and time.
4. Water cooling of the motor, enhancing the motor life.
5. Noiseless operation.
6. Underground installation, hence no land acquisition problems.
7. No necessity to enter the pit for removal of the pump.
8. No disturbance to the pipeline during pump removal in wet pit.
9. No bolting for connecting pump in pipeline, hence fast installation and easy removal in wet pit.
10. Automatic sealing of the pipeline during pump removal in wet pit.
11. Wide choice of mounting options : Auto Rail Coupling, Pedestal Coupling, Strainer Base, Goose Neck, Tube mounting, Base-frame, Horizontally suspended on floating barge, Trolley mounted.
12. Pumps with submersible motors can be installed in wet or dry pit with jacket.
Disadvantages
1. Limitation of maximum liquid temperature, should be less than 40 deg.C.
2. Motor parts including cable should be compatible to the liquid being pumped.
3. Electrical parts are submerged into the liquid.
4. Maintains requires special skills.
5. Pumps with submersible motors are generally expensive than pumps with standard TEFC motors.
6. Handling of submersible cable should be proper.
7. Sealing of submersible cable and motor joints is most important.
Cannot be used for liquids having crystallising tendency (Molten Sulphur) or acids