49

Question:

I am trying to find out what the number on the ring gasket stands for? If you have a RX-45, what does the 45 relate to?

No real relationship exists between ring gasket numbers and the flange size they fit.

Consider all flange and gasket terminology as a set of names, just as you would a set of names of people. For example, the name "Jean" tells you very little about a person: male or female, heavy or light, black or white.

Probably, because it seems intuitive to list flange sizes, small to large, and ring gaskets small to large; the first ring gaskets may have had numbers assigned in some manner that seemed to correspond to flange sizes. As the system of flanges and gaskets has expanded in number, size, and pressure ratings, the seeming correspondence has disappeared.

Consider this set of examples:

When the R series of ring gaskets came to exist after the flanges, the numbers increased as the size of flange increased, but had no real relationship to the size of the flange. Some Flanges that seal with R gaskets have had gasket numbers reassigned, e.g. 2-1/16" 3,000 flanges originally sealed with R-23 gaskets but now seal with R-24, these flanges will not mate as the gasket dimensions don't match.

RX Ring Gaskets have come into being as an improvement on R Ring Gaskets. They fit all the same flanges that seal with R Ring Gaskets, with the added feature of a "Pressure Energized" characteristic.

For more information about "Pressure Energized" Ring Gaskets, Click Here.

When 10,000 psi and higher pressure flanges came into use, they entered service in an as required sequence, and the BX gasket numbers got assigned in the order the flange appeared; the 5-1/8" 10,000 flange appeared later in service than the 21-1/4" 10,000 flange, and as a result the BX ring gasket for the smaller flange has a higher assigned number.

To obtain the dimensions of, and gasket numbers for, API Spec 6A or 17D flanges, go to http://www.woodcousa.com/flange/slidemenu.htm,  scroll down to the first drop down box and click on the arrow. You may select any API Spec 6A or 17D flange size to view a dimensioned illustration.

For a Catalog for Bolts, Nuts, Ring Gaskets and Wrenches, Click Here.

Information above, and in other parts of this Web Site, may help persons who really seek to know. If you have a question, and you think WOODCO USA may have the capacity to answer it, please use our Contact Us link and give us a chance to help.

WOODCO USA provides Web Site Tools for identification, estimating, and reference only. Do not use this information for manufacturing or inspection. Users of these tools should not use them as a substitute for professional engineering advice.  Anyone making use of the information presented does so at his own risk and assumes any and all liability resulting from such use.