Metallic Gaskets For Pipe Flanges - American Completion Tools

	Metallic Gaskets For Pipe Flanges

Ring Joint Gaskets are either octagonal or oval made to ASME B 16.20 in various sizes. These are identified by numbers R, RX or BX that relate to Flange size, pressure, class, and appropriate standards ASME B 16.20 or API 6A.

Materials for these gaskets are selected based on suitability for service conditions. It is essential that Ring Joint Gaskets be of a hardness lower than the Flanges. The recommended hardness and their identification is given in table below:

1.2 BOLTING REQUIREMENT FOR API END FLANGES
(Applicable ASTM Specification)
TABLE - 1

RING GASKET MATERIAL	MAXIMUM HARDNESS		IDENTIFICATION
	BRINELL	ROCKWELL 'B' SCALE	ASME B16.20	API - 6A
SOFT IRON	90	56	D	D - 4
LOW CARBON STEEL	120	68	S	S - 4
4-6 CHROME 1/2 MOLY	130	72	F5
TYPE 410	170	86	S 410
TYPE 304	160	83	S 304	S 304 - 4
TYPE 316	160	83	S 316	S 316 - 4
TYPE 347	160	83	S 347

These Gaskets are marked with - API Monogram - Gasket Type and No.-Identification - Date of Mfg.