The ANSI Pump Standard 14-5

The McNally Institute

ANSI is an acronym used to describe the American National Institute Pump Standard. The standard evolved from the American Voluntary Standard (AVS) that was first proposed by the Manufacturing Chemists Association in the nineteen fifties. It is a set of inch dimensional standards that describe the envelope dimensions of a back pull out, centrifugal pump.

If you live in the United States, the ANSI pump standard is probably the only pump standard you will ever use. Among the standardized dimensions you will find:

The location of the pump holds down bolts.
The distance between the suction and discharge nozzle centerlines.
The height of the pump coupling.

ANSI Pump Standards

There are currently three overall standard pump lengths:

17.5 inches
23.5 inches
33.875 inches.

The European equivalent of this standard would be the ISO (International Standards Organization) standard. Germany has their own standard called the DIN (Deutsche Industrial Norm).

The ANSI pump standard has gone through several revisions since it was originally adopted and there is lots of talk about combining it with the present API (American Petroleum Institute) standard to create a single standard for centrifugal pumps in the United States. The result of this merger is going to be a combination of the problems inherent in both these standards.

The main problem with this and similar standards is that they were written for packed pumps and are only now changing to reflect the increasing usage of mechanical seals. The most obvious change has been the acceptance of oversize stuffing boxes, but these standards still have a very long way to go. Ultimately the ANSI committee is going to have to accept the fact that short pumps with very low shaft L3/D4 numbers is the logical approach if American pumps are going to stay competitive.

In the following paragraphs you will find all the dimensions of the ANSI pump standard, end suction centrifugal pump:

The next diagram shows the detail of a typical ANSI pump and names the individual parts

The McNally Institute

OEE: Overall Equipment Effectiveness

Oh "Overall Equipment Effectiveness", I've heard about that before! Unfortunately, in many facilities, that's all OEE (Overall Equipment Effectiveness) is to the personnel. Something they heard of, talked about or read about. Many maintenance departments today still do not effectively utilize the OEE tool even though it's widely used among the world class companies.

What the Pump Was Designed to Do and Why it Doesn't Do it

Contrary to popular opinion, a centrifugal pump is not designed to develop one head at a single capacity as requested by the pump purchaser. In fact a pump is designed and produced to supply a whole range of head-capacity conditions as identified on it’s performance curve. The pump will operate on that curve if it is driven at the particular speed for which the curve is drawn.

What is Wrong with the Modern Centrifugal Pump?

Ask for a modern centrifugal pump recommendation from your favorite supplier and chances are he will recommend one of the standard pump designs that conform to either the A.N.S.I., I.S.O. or D.I.N. specifications. On the surface that might seem like a good recommendation, but the fact is that all of these designs will cause you maintenance problems. Refer to the illustration prior to diving into the details of the obvious problems found within these designs.

Digging Up Savings: Go with the Flow

It's important to find out if material flows are present or not throughout a bulk-processing facility; material cost savings and increased plant efficiency can offset an investment in monitoring. Most bulk solids processors can do this using low-cost acoustic emission-monitoring technology.

Chain Drive Design Recommendations

For optimum chain drive performance the following points should be considered when looking at chain drive design.

Classifying Chemicals to Assure Effective Sealing

The most common question asked by seal salesmen is "what are you sealing?" This is usually followed by asking about shaft size, product, temperature, speed, stuffing box pressure and any other operating conditions they can think of. The problem with this simplistic approach is that you would have to have a very large data bank of information to reference a particular problem so as to be able to make a sensible seal recommendation. There is a much more logical approach to the problem that we will be discussing in the following paragraphs.

A Guide to Matching Electric Motors with Hydraulic Power Units

Sizing electric motors correctly for hydraulic power units can save a sizable amount of money over the life of the equipment. If system pressure and flow are constant, motor sizing simply boils down to the standard equation: hp = QP / 1714EM

The ANSI Pump Standard 14-5