PROCESS ROTATING EQUIPMENT ( ) Slide No: ١
Pumps can be divided into two main groups: Displacement pumps Dynamic pumps Slide No: ٢
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BASIC CENTRIFUGAL PUMP PARTS Casing Axial horizontal split case pump Slide No: ٦
Multistage axial horizontal split case Pump Slide No: ٧
Single stage axial vertical split case pump Slide No: ٨
Barrel casing Slide No: ٩
Impellers Slide No: ١٠
Shafts Slide No: ١١
Bearings Partially filled Slide No: ١٢
Bearings Grease lubricated Slide No: ١٣
Bearings Slide No: ١٤
Spherical bearings Slide No: ١٥
Sleeve bearings Slide No: ١٦
Thrust bearings Slide No: ١٧
Stuffing Boxes Slide No: ١٨
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Packing and seals Slide No: ٢٠
Packing and seals Slide No: ٢١
Mechanical seal Slide No: ٢٢
Wearing Rings: Slide No: ٢٣
Couplings Chain coupling Slide No: ٢٤
Diaphragm coupling Slide No: ٢٥
Elastomeric coupling: Slide No: ٢٦
Flexible Disc coupling: Slide No: ٢٧
Flexible link coupling: Slide No: ٢٨
Gear coupling Slide No: ٢٩
Leaf spring coupling: Slide No: ٣٠
Metallic Grid coupling: Slide No: ٣١
Metallic Grid coupling: Slide No: ٣٢
Pin Drive Coupling: Slide No: ٣٣
TYPES OF Volute Diffuser Regenerative - Turbine Mixed-flow Single stage Multi stage Submersible Can Horizontal Axial-flow (propeller) Slide No: ٣٤
Volute- type pumps: Slide No: ٣٥
Diffuser-type pump Slide No: ٣٦
Turbine-type pumps Slide No: ٣٧
Mixed flow type pumps Slide No: ٣٨
Axial flow type pumps Slide No: ٣٩
Single stage and multistage pumps There are three common types of multistage pumps: - Submersible - Can - Horizontal Slide No: ٤٠
Vertical pumps (submersible) Slide No: ٤١
Can type pumps Slide No: ٤٢
Horizontal Slide No: ٤٣
HEAD ON A PUMP The amount of energy transferred to the fluid in a centrifugal pump is called the head of the pump. Head is not the same as pressure. This is a very important concept, which will be explained in the following paragraphs Slide No: ٤٤
Pressure: Terms and Definitions Three pressure terms commonly arise in pumping problems-absolute, barometric, and gauge pressure. A fourth term, vacuum, is used with installations operating below atmospheric pressure, but it is not a pressure term in the same sense as the first three. Slide No: ٤٥
Absolute pressure is the pressure above absolute zero. It may be above or below the atmospheric pressure existing at the point under consideration. Barometric pressure is the atmospheric pressure at the locality being studied and varies with altitude and climatic conditions. Gauge pressure is the pressure above atmospheric at the locality where it is measured. A vacuum is a negative gauge pressure Slide No: ٤٦
Head: a column of water or other liquid in a vertical pipe exerts a certain pressure (force per unit area) on the horizontal surface at the bottom of the pipe. This pressure can be expressed in pounds per square inch (psi) or as the number of feet of liquid, which exert an equal pressure on the same surface. The weight of the column of liquid producing the pressure in question is known as the head on the surface. Note that is the weight of the liquid acting on the surface that produces the pressure. Slide No: ٤٧
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Static Head: In pump application the height of a column of liquid acting on the pump suction or discharge is often termed the static head on the inlet or outlet and is expressed as a certain number of feet of the liquid. Static head is a difference in elevation and can be computed for a variety of conditions surrounding a pump installation. Slide No: ٤٩
Vapour Pressure: Every liquid at any temperature above its freezing point exerts a pressure due to formation of vapour at its free surface. This pressure, known as the vapour pressure of the liquid, is a function of the temperature of the liquid the higher the temperature, the higher the vapour pressure. Vapour pressure is an important factor in the suction conditions of pumps handling liquids of all types. In any pumping system the pressure at any point should never be reduced below the vapour pressure corresponding to the temperature of the liquid because the liquid will form vapour, which will partially or completely stop liquid flow into the pump. Slide No: ٥٠
Static Suction Lift: This is the vertical distance, in feet, from the liquid supply level to the pump centreline, the pump above the supply level. Horizontal runs are not considered as part of the static suction lift, so far as lift is concerned Slide No: ٥١
Static Suction Head: Where the pump is below the liquid supply level a static suction head exists. Numerically, it is the vertical distance, in feet, between the liquid supply level and the pump centreline. Slide No: ٥٢
Static Discharge Head: This is the vertical distance, in feet, from the pump centre line to the point of free delivery of the liquid Care must be exercised to see that the point of free delivery is used when computing static discharge head. In some layouts the exact point may be difficult to determine. This is discussed in greater detail later in this chapter. Slide No: ٥٣
Total Static Head Total static head on a pump is the vertical distance, in feet, between the supply level and the discharge level of the liquid being handled. Friction Head: Measured in feet of the liquid handled, this is the equivalent head needed to overcome the resistance of the pipe, valves, and fitting in the pumping system, friction head exists on both the suction and discharge sides of a pump, and varies with liquid flow rate, pipe size, interior condition of the pipe, type of pipe, and nature of the liquid being handled. Slide No: ٥٤
NPSH definition: Total inlet pressure, in meters or feet of liquid pumped determined at the pump suction connection (i.e. suction flange), minus the vapour pressure of the liquid pumped in meters or feet of liquid pumped at pumping temperature. Two NPSH definitions are used in pumping systems : Net Positive Suction Head available (NPSHa), Net Positive Suction Head required (NPSHr). Slide No: ٥٥
Cavitaion Slide No: ٥٦
Pitting accompanying cavitation in a Centrifugal pump Slide No: ٥٧