The oval section ring gaskets were originally designed for the now obsolete round bottom groove. Both the Oval and the Octagonal cross section are interchangeable on the flat bottom groove design. These gaskets are manufactured as per API 6A / ASME B16.20 to suit API 6B and ASME B16.50 flanges.
As a result of metal to metal sealing media they are made to be free of indentations, tool marks etc and have a surface finish of maximum,
· R, RX – 63 microinches Ra (1.6 micrometer Ra).
Thus Gasket supplies ring joint gaskets (RTJ Gasket) with the hardness numbers as follows:
GASKET MATERIALS |
BRINELL HARDNESS NUMBER (max) |
ROCKWELL HARDNESS NUMBER (max) |
IDENTIFICATION |
---|---|---|---|
Soft iron | 90 | 56 | D |
Low carbon steel | 120 | 68 | S |
4-6% Chrome 1/2% molybdenum | 130 | 72 | F5 |
304 Stainless Steel | 160 | 83 | S304 |
316 Stainless Steel | 160 | 83 | S316 |
347 Stainless Steel | 160 | 83 | S347 |