Rotodynamic (Centrifugal) Slurry Pumps

12.0 Scope

This Standard is for rotodynamic (centrifugal), singlestage, overhung impeller slurry pumps, horizontal and vertical of industrial types, herein referred to as slurry pumps. It includes types and nomenclature; definitions; design and application; and installation, operation, and maintenance.

Air-Operated Pumps

10.1 Types and nomenclature

An air-operated pump is a positive displacement reciprocating pump used for general liquid transfer. It is driven by means of a compressed gas (usually air) from an outside source. Where “air” is used throughout this document, it should be taken to mean any compressed gas, but usually air.

Air-operated rotodynamic and rotary pumps are not included in this standard.

Pumps - General Guidelines

9.0 Scope

This Standard applies to all industrial/commercial pumps, including centrifugal, vertical, rotary and reciprocating types. It includes: types; definitions; design and application; airborne sound measurement and decontamination.

9.1 Types of pumps

Industrial/commerical pumps are used in an infinite variety of applications, and many different configurations of design are used to satisfy these requirements.

The different designs can be typified diagrammatically, as shown in Figure 9.1 on the following page. The first distinction is the manner in which the machine adds energy and moves the liquid.

9.1.1 Positive displacement pumps

Positive displacement pumps add energy by trapping liquid in a confined space and forcibly moving it out of the pump and into the discharge pipe. This pumping action is done by one of three methods:

1) Reciprocating action of plungers, pistons, bellows or diaphrams;

2) Rotary action of mechanical devices such as gears, screws, vanes, etc.;

3) Blow case arrangements using pressurized air to displace liquid.

9.1.2 Kinetic pumps

Kinetic pumps add energy by high-speed rotating wheels or impellers and fall into the following categories:

– Centrifugal, both horizontal and vertical turbine types;

– Regenerative turbine;

– Rotating casing with pitot tube.

Direct-Acting (Steam) Pumps

8.0 Scope

This Standard applies to direct acting (steam) pumps. It includes types and nomenclature; definitions; design and application; and installation, operation and maintenance.

Controlled-volume Metering Pumps

7.0 General description of controlled-volume metering pumps

Controlled-volume metering pumps (also known as metering pumps, proportioning pumps, chemical injection/ feed pumps, or dosing pumps) are reciprocating positive displacement pumps typically used for the injection of chemical additives, proportional blending of multiple components, or metered transfer of a single liquid. These types of pumps are used in applications requiring highly accurate, repeatable, and adjustable rate of flow.

The rate of flow of a controlled-volume pump is a function of the cross-sectional area of the plunger or piston, or displacement of the diaphragm; the stroke length; and the stroking speed. The pumping action is created by a reciprocating piston and controlled by suction and discharge check valves. The rate of flow is adjusted by changing the stroke length and/or the stroking speed.

Controlled-volume metering pumps are characterized by their ability to meet specific performance requirements concerning steady state accuracy, repeatability, and linearity.

Reciprocating Power Pumps

6.0 Scope

This Standard applies to reciprocating power pumps. It includes types and nomenclature; definitions; design and application; and installation, operation and maintenance.

Sealless Centrifugal Pumps

5.1.1 Scope

To develop the definitions and construction for sealless pumps that are driven by canned motors or magnetic couplings. These standards include types and nomenclature; design and application; installation, operation and maintenance; and test. Not included are submersible wastewater pumps which do not have external shaft seals and are therefore not susceptible to external shaft leakage.

Seal less Rotary Pumps

4.0 Scope

This standard covers the unique features of sealless rotary pumps and includes sections on: types and nomenclature; definitions; design and applications; installation, operation and maintenance; and test.

Rotary Pumps

3.1.1 Scope

This Standard applies to industrial/commercial rotary positive displacement pumps. It includes: types and nomenclature; definitions; design and application; and installation, operation, and maintenance. It does not include standards on magnetic drives for sealless pumps nor rotary pumps primarily used for fluid power applications.

Rotodynamic (Vertical) Pumps

2.1.1 Scope

This standard is for types, nomenclature, and definitions of vertical turbine, mixed flow, axial flow vertical diffuser, submersible motor deepwell and short-set pumps, types VS0, VS1, VS2, VS3, VS6, VS7, and VS8 (Figure 2.1.3) that are driven by vertical electric motors or horizontal engines with right-angle gears.

Excluded from the scope of this document are vertical in-line volute pumps; horizontal centrifugal pumps mounted vertically, such as sewage pumps; and vertical overhung impeller types VS4 and VS5 (Figure 2.1.3).

Rotodynamic (Centrifugal) Pumps

Rotodynamic (Centrifugal) Pumps

1.1 Types and nomenclature

Rotodynamic pumps may be classified by such methods as impeller or casing configuration, end application of the pump, specific speed, or mechanical configuration. The method used in Figure 1.1.3a is based primarily on mechanical configuration.

Troubleshooting Rotary Lobe Pumps

The rotary lobe pump belongs to the positive displacement pump family. It is a dual shaft pump design with external timing gears, allowing two intermeshing rotors to operate synchronously. The pump operation is similar to the function of a positive displacement blower: Minimized clearances between rotors and the pump casing allow pumping action by forming a seal with the liquid between the suction and discharge side. Most positive displacement pumps need to be operated with elastomers (progressive cavity pumps, hose pumps, diaphragm pumps, plunger pumps, etc.). Since the rotary lobe pump incorporates a timing gear, non elastic rotors like steel or stainless steel rotors can also be used. Since the rotary lobe pump has no preferred rotation direction, it can be operated in a reversible mode

Reciprocating Pumps vs. Multi-Stage Centrifugal Pumps - Page 2

Centrifugal Pump
Since a centrifugal pump has no fixed volume (as indicated above) at a fixed inlet size and casing, increasing the diameter of the impeller or the rotational speed will lead to increased head and increased flow rate.
A centrifugal pump can have a large capacity with a small footprint compared with a reciprocating pump. Of course, increased capacity will consume more energy. Capacity is proportional to impeller speed and diameter. Larger impeller diameter (higher exit velocity) (see Figure 3) and/or faster rotation speed will increase the head due to conversion of velocity to head.

Reciprocating Pumps vs. Multi-Stage Centrifugal Pumps

Many times, you may be faced with the decision to use a reciprocating pump or a multi-stage centrifugal pump for a given application. There are some pros and cons for either pump design, depending on:

• Where the pump is to be installed
• The fluid being transferred
• Future expansion plans
• Variable system parameters
• Operation and maintenance issues
• Personnel knowledge and experience with the pumps

Pump Rebuilding and Balancing

Pump Rebuilding and Balancing (Part One)

Written by Dawn Hines and Robin DeRousse, Hines Industries, Inc. and Jerzy Moszynski, MS ANSIFLO Pump

Pumps and pump systems are unique, engineered products that require specialized knowledge in all phases of repair, rebuilding and balancing. When pumps fail, costs add up quickly for repairs, replacement parts and plant downtime. Costs for lost production alone can add $5,000 to $200,000 per hour to the total cost of a pump failure.