Sealing arrangement specifically for shut off devices

In a sealing arrangement for a valve having a valve seat member and a cooperating valve closure member, a thin-walled elastically deformable member carried by one of said valve members and which is engageable with the other of said valve members substantially in line contact therewith, and means for moving one of said valve members laterally relatively to the other of said valve members to seat said thin-walled elastically deformable member on the other of said valve members, the improvement comprising:

• each of said thin-walled elastically deformable member and said other valve member being comprised of a metal body of a hardness in excess of 30 HRC (298 HV);
• a continuous coating on top of one of the metal bodies and being of a soft, ductile metal of a hardness appreciably less than the hardness of said metal body and located at least at the area of said line contact and overlying thereat the surface of said metal body completely filling any surface, discontinuities, micropores and interstices;
• said soft metal coating being shearing by lateral movement of said valve and deformable members relatively to each other by abrasive action of the hard metal surface onto the soft metal surface until establishment of direct contact between the surface of the hard metal body without coating and the exposed hard metal areas of the metal body provided with the coating, the surface discontinuities, micropores and interstices of later metal body remaining filled by said soft metal such that the mechanical closure forces are carried and transmitted by the exposed hard metal body areas only, and said no load carrying surface discontinuities, micropores and interstices remain filled by said soft metal to ensure a perfect seal.