Buttweld Fittings General
A pipe fitting is defined as a part used in a piping system, for changing
direction, branching or for change of pipe diameter, and which is
mechanically joined to the system. There are many different types of
fittings and they are the same in all sizes and schedules as the pipe.
Fittings are divided into three groups:
- Buttweld (BW) fittings whose dimensions, dimensional tolerances et
cetera are defined in the ASME B16.9 standards. Light-weight corrosion
resistant fittings are made to MSS SP43.
- Socket Weld (SW) fittings Class 3000, 6000, 9000 are defined in
the ASME B16.11 standards.
- Threaded (THD) fittings Class 2000, 3000, 6000 are defined in the
ASME B16.11 standards.
Image of most used buttweld fittings.
Applications of Buttweld Fittings
A piping system using buttweld fittings has many inherent advantages over
- Welding a fitting to the pipe means it is permanently leakproof
- The continuous metal structure formed between pipe and fitting adds
strength to the system
- Smooth inner surface and gradual directional changes reduce pressure
losses and turbulenceand minimize the action of corrosion and erosion
- A welded system utilizes a minimum of space