scope:

This specification covers gaskets of Navy design for use in Navy flanged joints in steam piping systems for temperatures up to and including 875 degrees Fahrenheit (°F).

The PIN for the gaskets covered by this specification shall consist of a general prefix followed by a specific design designator. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, ATTN: 05Q42, Naval Sea Systems Command, 2531 Jefferson Davis Hwy, Arlington, VA 22242-5160 by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

The prefix shall consist of the letter "M", and the basic number of this specification. The design designator shall consist of the size, pressure rating series, metal outer ring finish and filler material type as shown in the following example:

The NPS and actual dimensions of the gaskets can be obtained from tables I and II.

Pressure rating shall be as follows:

Pressure Rating (PSI) Reference 150 Table I 300 Table II 400 Table II 600 Table II

The metal outer ring material and finish options (see 3.2.2) shall be identified as follows:

Code Metal outer ring material/finish CRPL Carbon steel ring/chromium plated CRES Corrosion resistant material, as specified, ring/uncoated UNC Carbon steel ring/uncoated REF No metal outer ring Blank Carbon steel ring/vendor coating option

NOTE: "CRES" metal outer rings may be provided in lieu of "CRPL" metal outer rings at the manufacturer's option. "CRES" metal outer rings may be substituted for "CRPL" metal outer rings in service.

Gasket fillers shall be one of the following materials:

GRA - Flexible graphite filler material to MIL-P-24503 ASB - Asbestos paper filler material to MIL-A-24058

intended Use: