Beginners Guide to Pumps

Know Your Pumps

Every industry today requires a pump somewhere in its operation. From food processing to oil wells, pumps play a critical role in the production and maintaining our standard of living. Pipes carry the fluid, but pumps supply the energy to move it. Because the piping and pumps work together, they must be thought of and designed as an integrated system. Change one part, and the system can become less efficient.

In this Beginner’s Guide to Pumps, we attempt to keep the Information basic and non-technical as possible. Bear in mind that pumping systems are highly technical in nature. Every length of pipe, elbow, valve, the height of the pump above or below the reservoir, fluid viscosity and inside diameters of all equipment affect the optimal discharge flow for the system.

This guide also covers the short history of pumps to see how they evolved over time. We then cover the basic parts, Types of Pumps, and the industries that use them. Lastly, we include some basic troubleshooting topics.

We hope that you find this guide useful. When it comes time to planning for a new pumping system or repairing an existing one, you can rely on the experts at All Pumps to get the job done right the first time… EVERY TIME.

169

K+

Different Applications
on Record

,500

Pumps Serviced
This Year

Star

Stars Rating from 2,729 Customers

M+

Possible Pumps Configurations

How Pumps Work

Pumps are divided into two main classifications, but all work by creating a vacuum in which ambient air pressure forces the liquid. All types of pumps create areas of low pressure to start operation. In a centrifugal pump, centrifugal force accelerates the water to the outside of the impeller creating a low pressure at the eye or centre of the impeller. With reciprocating pumps, the upstroke of the plunger or piston creates a vacuum. In gear pumps or lobe pumps, as the teeth or lobes mesh then come apart, a vacuum is created. In all these types, it is the difference in pressure that creates suction. A liquid under higher pressure will move to an area of lower pressure.

Pressure Terminology For Pumps

Atmospheric Pressure — At sea level, air pressure exerts a pressure of 14.7 psi all around us. By placing one end of a tube in water and applying a perfect vacuum to the other end, that 14.7 psi could hold a column of water 33.9 feet high. However, this is only attainable at sea level and with a perfect vacuum. Centrifugal pumps can lift water no more than 26 feet at sea level because the pressure drops off approximately 2 feet for each 1000 feet of altitude above sea level.
Head — Head refers to the height at which a pump can raise a fluid and can be calculated from H (metres)= pressure in kPa/ (9.8 x specific gravity).
Static Suction Head — The vertical distance between the centre line of a pump and the level to which the liquid is pumped.
Suction Lift — The distance between the level of where the liquid enters the suction line to the height of the centre line of the pump when the pump is higher than the reservoir.
Vacuum — Defined as any pressure lower than atmospheric. Each pump creates a vacuum into which fluids flow under atmospheric pressure. Pumps create low pressure or suction in a variety of ways and define the type of pump. Pumps that rotate use centrifugal force to accelerate the fluid, creating low pressure in the centre of the impeller. Positive displacement pumps use plungers, pistons or diaphragms to displace water and create a vacuum using a linear reciprocating motion of a piston moving in and out of a cylinder.

Pump Performance

Pumps have strict tolerances and precise conditions under which they must operate to generate the Best Efficiency Point or BEP. Every pump has a chart showing the performance curves and how to attain the BEP. Pump manufacturers calculate performance curves with a pressure gauge and a flow meter connected to the discharge port to find the optimal configurations of piping, type of fluid and head. The discharge capacity can be calculated for any head.

Considerations for BEP
Pump performance factors include:

How high the pump will sit above the water source (static suction head).
How high the discharge end is above the pump (static discharge head)
Determine what the discharge capacity at gallons per minute (GPM).
Friction losses to fluid viscosity, type and length of hose or pipe.
Altitude above sea level where the pump will operate.
Discharge Head or height of the discharge above the pump.
Restrictions, couplers, elbows and valves.

As you can see, there are several forces acting upon a pump that directly affects its performance. Each force has a mathematical calculation that helps define the BEP for each pump. Consider pump performance curves from manufacturers as your mathematical cheat sheet to help you select and properly install the right pump for your application.

Basic Parts of PUmps

Although pumps come in all shapes, sizes and configurations, most pumps contain five basic components:

The Casing

this is the outer shell or housing that encases the pump and can be made from different materials depending on the duty fluid and other system requirements.

Fluid Displacement Device

The two main ways of moving fluid are centrifugal and positive displacement. In centrifugal pumps, impellers are the rotating discs with fins or vanes attached. They spin rapidly to accelerate the fluid outwards to the discharge port. Meanwhile, positive displacement pumps use different types of pistons, gears, lobes or screws to pump fluids.

Bearings

A set of mechanical support that allows continuous rotation of the impeller, reduces the rotational friction, and supports the loads in other pump assemblies.

The Hub

The central part of a wheel attached to the bearing assembly. It is the source of power for impeller rotation in centrifugal pumps.

The Mechanical Seal

Protects the bearing assembly from excess grease loss and contamination. Seals also keep fluids inside the pump from leaking while allowing the shaft to spin or reciprocate depending upon the type of pump.

Pump Parts

Volute Casing
Wear Ring
Impeller
Screw Plug
Mechanical Seal
IEC StandardMotor
Adapter
Slinger
Shaft
Impeller Nut

INDUSTRIES & APPLICATIONS

We find pumps in every area of our modern lives. They are important equipment needed in the manufacture of almost all essential goods we consume and use every day. From running water to the box of cereal on the table, they all require pumps as part of the process.

General industries that rely on pumps are:

Within each industry, there are many variations of pumps depending upon the amount and type of fluid they move. Let’s look at some types used by each industry.

Industrial

Industrial pumps are typically part of an assembly process. These pumps move liquids from a storage tank to be mixed with other components like a chemical process or directly applied to a part such as paint. Industrial pumps must be built to withstand highly corrosive or volatile chemicals, extremely high or low temperatures, high pressure and constant use. Pump materials and construction vary depending upon the liquids they handle and their environment. Pumps used for industrial purposes include both centrifugal pumps and positive displacement pumps.

Mining, Oil and Gas

Most mining operations are always battling rising water from underground sources. The processing of ores also involve fluid handling. Multiple tons of liquid carrying mud, rocks, and chemicals need to be moved every day. Because of the highly demanding nature of fluid handling in the mines, the pumps to be used should be robust enough to withstand extreme abrasion and corrosion. The most common type used in the mines is the “Trash” or “Slurry” pump. It is built to let small stones pass through the pump without damaging the impeller.

The oil and gas industry uses a variety of pumps due to the different densities of fluids such as crude oil, distillates, gas and slurries. In drilling operations, cement or mud is pumped around the well casing to hold the pipe in place and seal the well. Crude oil is typically high viscosity and very hot when pumped to the surface. Along with the oil is a variety of corrosive and toxic gasses such as H2S or Hydrogen Sulphide. The gas must be separated and pumped to a holding tank or pumped to a flare boom where it is released and burned. H2S will corrode iron aggressively, so pumps used in this industry should be made from anti-corrosive materials. Some operations will also require pumps with ATEX certification. Both centrifugal and positive displacement types are used.

Building and Construction

If you live or work in a building higher than two storeys, you can thank a pump for the water pressure. Every tall building uses pressure booster pumps or multistage centrifugal pumps to push water to the top and to pressurize fire water systems. Submersible pumps also move sewage water to the central sewer lines.

Food Manufacturing

Every bottle of sauce or oil found in a grocery store requires a food-grade pump for production and packaging. Food manufacturing facilities require pumps for most processes. For example, in fresh vegetable production, the cut vegetables undergo sanitisation by pumping through a chlorinated closed flume system.

The canning industry requires pumps that handle live steam and boiling liquids such as soup and stews. For buildings handling frozen food, cryogenic pumps handle liquid nitrogen or other pressurized gas at below freezing temperatures.

Pumps in the food industry are not limited to liquids. They must move powders, granulated solids, whole grains and finished cereals all without damaging the products. Centrifugal pumps are the most common but there are also hygienic positive displacement pumps