WHAT IS MSS?
Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry is a non-profit association organized for development and improvement of industry, national and international codes and standards for: Valves, Valve Modification, Pipe Fittings, Pipe Supports, Flanges, etc.
WHAT IS MSS-SP-43 SOCKET WELD FITTING?
A Socket Weld is a pipe attachment detail that involves inserting a pipe into a recessed region of a valve, fitting, or flange. MSS SP 43 socket weld fittings are designed for low-pressure, corrosion-resistant applications. The fittings include 90 degree and 45 degree long radius elbows, straight and reducing tees, etc. This Standard Practice specifies the dimensions, tolerances, and markings for socket weld fittings used in low-pressure, corrosion-resistant applications.
PRESSURE RATINGS
The fittings covered by this Standard Practice are not pressure rated, but they must be able to withstand 30% of the pipe’s allowable pressure rating.
MARKINGS – According to this Standard Practice, every fitting must be marked to show the following:-
- Name of manufacturer or their trademark
- Material designation shall be marked in accordance with ASTM, ASME or other recognized material specifications
- Size
- Melt identification and material symbol
- Valve trim identification
- Identification of threaded ends
MATERIALS – Fittings made from AISI Types 304, 304L, 347, 316, and 316L are considered standard under this specification.
TYPES OF SOCKET WELD FITTINGS
The various types of MSS-Sp-43 Socket weld fittings are mentioned below.
- Elbows 45° and 90° – Used to make a 45 degree direction change in piping and 90 degree turn in small piping respectively.
- Crosses – They are used sparingly because it is preferable to use two Tees for procurement.
- Couplings – This is used to join two plain end pipes together.
- Half-Couplings – They’re used on big lines as a small bore branch.
- Tees – Using these fitting branches are connected at a 90° angle.
- Union – It is used to connect pipes of various diameters in cases where the pipe is dismantled frequently.
- End or Pipe Caps – They are used to close the dead end of a small bore pipe with a plain end.
APPLICATIONS OF SOCKET WELD FITTINGS
- To convey steam
- To transport Flammable liquids and gases
- To transport Acids & toxic liquids
- Installations with a long service life
- Installations with a high level of durability
