MSS: Manufacturers Standardization Society of the Valve and Fittings Industry, Inc.

MSS, the Manufacturers Standardization Society of the Valve and Fittings Industry is a non-profit standards developing organization that is devoted to the development of the industry. Standards written by MSS address valves, valve actuators, valve modification, pipe fittings, pipe hangers, pipe supports, flanges, and associated seals. These materials and associated guidelines are used in almost every industry, and are found in facilities for waste management, nuclear energy, and oil refining. Standards from MSS are available both individually, directly through the ANSI webstore, and as part of a Standards Subscription. If you or your organization are interested in easy, managed, online access to standards that can be shared, a Standards Subscription may be what you need - please contact us at: [email protected] or 1-212-642-4980 or Request Proposal Price.

Below are MSS's best-selling standards. To find additional standards, please use the search bar above.

ANSI/MSS SP-58-2018

Pipe Hangers and Supports - Materials, Design, Manufacture, Selection, Application, and Installation

This Standard Practice establishes an industry accepted basis for Manufacturers, Engineers, Erectors, Purchasers, Inspectors, Draftsmen, and others involved in the Materials, Design, Manufacture, Selection, Application, Inspection, and Installation of pipe hangers and supports and their components for piping systems of all service temperatures.

ANSI/MSS SP-55-2011

Quality Standard for Steel Castings for Valves, Flanges, Fittings, and Other Piping Components - Visual Method for Evaluation of Surface Irregularities

This Standard Practice is intended to supplement the requirements of ASTM Specifications A216/A 216M, A217/A217M, A351/A351M, A352/A352M, A3891A389M, A487/A487M, and A744/A744M and to provide a series of reference photographs typical of the various surface irregularities common to steel pressure castings and illustrations of generally acceptable and generally rejectable quality. Table 1 of Section 5 is provided to show MSS interpretation as to the relationship between this Standard Practice and the levels of surface quality illustrated by the comparators and the photographs of the Steel Casting Research and Trade Association (SCRA TA) Comparators for the Definition of Surface Quality of Steel Castings.
For additional nondestructive examinations defining quality of steel castings, this Standard Practice may be supplemented by the following Standard Practices; SP-53 "Magnetic Particle Examination Method", SP-54 "Radiographic Examination Method", SP-93 "Liquid Penetrant Examination Method", SP-94 "Ultrasonic Examination Method", and SP-112 "Visual and Tactile Method".

MSS SP-75-2019

High-Strength, Wrought, Butt-Welding Fittings

This Standard Practice covers factory-made, seamless and electric welded carbon and low-alloy steel, butt-welding fittings for use in high pressure gas and oil transmission and distribution systems; including pipelines, compressor stations, metering and regulating stations, and mains.

ANSI/MSS SP-25-2018

Standard Marking System for Valves, Fittings, Flanges, and Unions

This standard marking system applies to the marking of new valves, fittings, flanges, and unions used in piping connections that include (but are not limited to) flanged, soldered, brazed, threaded, or welded joints.

MSS SP-97-2019

Integrally Reinforced Forged Branch Outlet Fittings: Socket Welding, Threaded, and Buttwelding Ends

This Standard Practice includes essential dimensions, finish, tolerances, testing, marking, material, and minimum strength requirements for 90° and 45° integrally reinforced forged branch outlet fittings of buttwelding, socket welding, and threaded types.

MSS SP-127-2014a

Bracing for Piping Systems: Seismic - Wind - Dynamic Design, Selection, and Application

This Standard Practice establishes the material, design, fabrication, and inspection criteria to be used in the manufacture, selection, and application of standard types of bracing assemblies. This Standard Practice presents recommended guidelines for providing stability in piping systems for protection against seismic, wind, and other dynamic forces. This Standard Practice is intended for use on piping systems where formal engineered bracing design may not have been performed. Note that local and/or national building codes or regulations may supersede or augment these requirements. This Standard Practice applies to rigidly connected metallic pipe only (welded, flanged, mechanical-jointed, etc.). For other types of pipe and pipe connections, contact the applicable pipe manufacturer for information.

MSS SP-58-2009

Pipe Hangers and Supports - Materials, Design, Manufacture, Selection, Application, and Installation

(Incorporates content of SP-69, 77, 89, and 90.) Establishes the material, design, fabrication, and inspection criteria to be used in the manufacture of standard types of pipe hanger components. This Standard Practice establishes the allowable stress values for materials used in standard types of pipe support components and unique hanger design assemblies. This Standard Practice establishes minimum design load ratings for rigid pipe hanger assemblies (see Table 1). This Standard Practice presents the recommended practice for the selection and application of pipe hangers and supports for all service temperatures. This Standard Practice establishes recommended procedures for detailing, fabrication, and installation of pipe hangers and supports. SP-58-2009 incorporates contents of ANSI/MSS SP-69-2003, MSS SP-77-1995 (R 2000), MSS SP-89-2003, and SP-90-2000. SP-58-2009 supercedes MSS SP-58-2002.

MSS SP-89-2003

Pipe Hangers and Supports - Fabrication and Installation Practices

This Standard Practice establishes recommended procedures for detailing, fabrication, and installation of pipe hangers and supports. These procedures supplement, but do not replace, those of the manufacturer. Contents of this SP have now been incorporated into MSS SP-58-2009; however this SP is still active and available until officially withdrawn

ANSI/MSS SP-114-2018

Corrosion Resistant Pipe Fittings Threaded and Socket Welding Class 150 and 1000

This Standard Practice for corrosion resistant pipe fittings threaded and socket-welding, Class 150 and 1000, establishes requirements for the following: a) Pressure-temperature ratings; b) Size and method of designating openings of reducing fittings; c) Marking; d) Minimum requirements for materials; e) Dimensions and tolerances; f) Threading; g) Testing.

MSS SP-119-2010

Factory-Made Wrought Belled End Pipe Fittings for Socket-Welding

This Standard Practice covers the design and manufacturing requirements for factory-made wrought belled end pipe fittings for socket-welding formed from either tubular sections or flat material. Included are the overall dimensions, tolerances, materials, socket end details, heat treatment, marking and other requirements for belled end fittings in sizes NPS 1/2 through 12.