API (AMERICAN PETROLEUM INSTITUTE) STANDARD 18-4

The API (American Petroleum Institute) standard is the one universal standard being used by oil refineries throughout the world. There is on going talk about combining this standard with the chemical industry ANSI (American National Standards Institute) standard for a single unified pump standard.

The problem with all standards of this type is that they have produced a failure rate in mechanical seals that exceeds 85%. The only part of a mechanical seal that is sacrificial is the carbon face and in better than 85% of the cases there is plenty of carbon face left when the seal begins to leak.

The A.P.I. specification addresses just about everything about mechanical seals. The subjects include:

In this section we will be looking at just a few of those parts of the A.P.I. standard 682 that when combined with the C.P.I. standard, will be affecting your seal purchases in the near future. Most of this information was taken from A.P.I. Standard 682, First Edition, dated October 1994. I recommend you get hold of a copy of this and any future updates to learn the full particulars.

2.1.1

2.1.2

2.1.5

2.1.6

2.1.7

2.2.6

2.27

 

2.3.3.1

2.3.5.1

2.3.5.2

2.3.10

2.3.18.1

2.3.20

2.4

2.4.1

2.4.3

2.4.4.4

2.4.5

2.4.6

2.4.8

2.4.9

2.4.10.2

2.5.1

2.6.1

3.2.2

3.2.3

3.2.4

3.6

3.7.2

4.2.1

4.2.3

4.5.4.1.1

Section 4.4.4 contains numerous references to dual seal system reservoirs.

4.5.5.1

Section 4.6 addresses the circulation of the buffer/barrier fluid.

There will be some benefits to the user when the API specification is adopted into the CPI industry

What is the problem with this API specification as a standard for the Chemical Process Industry? There are a lot of things I do not like about it in its present form. If combining with the CPI means a complete re-writing of the API specification that will be fine, depending upon the final result.

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