- Stainless Steel 304 Buttweld Fittings
- ASTM A403 WP304 Buttweld fitting
- SS 304 Pipe Fittings
- SS 304 Pipe Fitting
Being one of the more popular and versatile alloy grades, the Stainless Steel 304 Buttweld Fittings offers its users a massive advantage in terms of its price. Since the alloy is easily available and has good formability properties, the fittings are easily formed and have good durability, provided they be used in appropriation with their mechanical characteristics.
Regularly a preferred choice in the chemical processing as well as the petrochemical refining industry, the stainless steel 304 pipe fittings have good mechanical strength, which can be attested by the performance of a tension test on the samples. Usually, the astm a403 wp304 buttweld pipe fittings is a wrought austenitic alloy produced under the ASTM A403 specifiction is intended to be used in a piping system.
Since the specification caters to pressure based piping systems, the ss 304 reducer is used in chemical processing plants to change the size of a pipe from a larger to a smaller one, or vice versa. Since fittings like the ss 304 elbow can be used to change the direction of flow in a high pressured system, the alloy selected for its production needs to be sturdy. Hence a grade 304 makes a great choice for pressure related applications. The diameter of the branch size of a 304 ss reducing tee tends to be smaller as compared to the diameter of the Run Pipe.
|Specifications of Stainless Steel 304 Buttweld Fittings||American Society for Testing and Materials A403 / American Society of Mechanical Engineers SA403|
|ASTM A403 WP304 Buttweld fitting Size in Inch||1/8 Inch TO 48 Inch|
|SS 304 Pipe Fittings Standards||American Society of Mechanical Engineers/American National Standards Institute B16.9, American Society of Mechanical Engineers B16.28|
|Type of SS 304 Pipe Fitting||Seamless, Welded & Fabricated|
|Checmial Grade||Carbon (C)||Manganese (Mn)||Silicon (Si)||Phosphorus (P)||sulphur (S)||Chromium (Cr)||Molybdenum (Mo)||Nickel (Ni)||Nitrogen (N)|
|Stainless Steel 304 Buttweld Fittings||0.08 Maximum||2 Maximum||0.75 Maximum||0.045 Maximum||0.030 Maximum||18 – 20||-||8 – 11||-|
|Density||Tensile Strength||High Yield Strength||Elongation||Melting Point|
|8.0 gram/cm3||PSI 75000||PSi 30000||35 %||1400 °C (2550 °F)|
Defined in specification ASME B16.11, Socket Weld fittings are generally to be used for those pipes where the diameters are small. In a piping system pipe is inserted into a recessed area of the socket weld fitting. Since both the pipe as well as the socket weld fitting are square cut, there is no need for bevelled end or any further preparation apart from cleaning the outside. This is what permits easy welding and installation of socket weld fittings.
On the other hand, Buttweld fittings as defined in specification ASME B16.9, are a two piece fitting which is butted against each other, after which they are welded with their ends to the pipe end, with the same thickness as pipes. In order to provide ease in assembly the ends of butt weld fittings shall be bevelled.
With regards to their application, the fillet weld or a socket weld is mainly used in applications for Small Bore Piping with the diameters ranging from NPS 2 or smaller since it has the ability to resist approx 1/2 the strength of butt welding. While butt weld fitting exhibits better strength, especially for those applications involving high pressure or high temperature pipelines. Therefore, a butt weld is to be used when a welded joints strength is not lower in comparison to that of the base metal itself is required.
In terms of their features, a Socket weld is much easy to install in comparison to a buttweld. However, a Socket weld requires a gap of approx. 1/16 of an inch at the lower end of the pipe in order to socket into, which in turn permits thermal expansion. This gap could result in an overstress issue that cracks the fillet weld of the fitting. Socket weld often is considered to be troublesome in corrosive fluid service due to it being susceptible to crevice corrosion. Which is why it is easy for a Socket weld to get corroded due to the discontinuity of the smooth pipe internals.
Although a Butt weld is often described to be the pre-eminent in terms of its properties such as strength, fatigue, and corrosion resistance, as well as temperatures compliance; it is, however, more difficult to set up and weld properly. Therefore, using a Butt weld would not only require a skilled welder but also more time.