ASTM A403 and ASME SA403 are both specifications for wrought austenitic stainless steel pipe fittings. These specifications cover the standard requirements for butt-welded, seamless, and welded stainless steel pipe fittings for use in pressure piping and pressure vessel service at high temperatures.
ASTM A403 is the standard specification for wrought austenitic stainless steel piping fittings, and it covers the standard dimensions, materials, testing, and marking requirements for butt-welded, seamless, and welded stainless steel fittings. This specification applies to fittings of all sizes, NPS 1/2 through NPS 48, and to all schedules, including Schedule 5S, 10S, 40S, and 80S.
ASME SA403 is identical to ASTM A403 in terms of its requirements, but it is published by the American Society of Mechanical Engineers (ASME). ASME SA403 is typically used when procuring fittings for high-pressure, high-temperature applications, such as in the oil and gas industry or power generation plants.
Both ASTM A403 and ASME SA403 are widely used in various industries, including oil and gas, chemical, and petrochemical industries, for their reliable performance and durability.
The dimensions of ASTM A403 and ASME SA403 fittings are standardized and based on the nominal pipe size (NPS) and schedule. The dimensions include the outside diameter, wall thickness, center-to-end dimensions, and overall length.
For example, the dimensions for a 2-inch pipe with a schedule of 40S would be as follows:
- Outside diameter: 2.375 inches (60.3 mm)
- Wall thickness: 0.154 inches (3.91 mm)
- Center-to-end dimensions:
- Long radius elbow: 3 inches (76.2 mm)
- Short radius elbow: 2 inches (50.8 mm)
- Tee: 3 inches (76.2 mm)
- Reducer: 5 inches (127 mm)
- Overall length: 4.5 inches (114.3 mm) for elbows and tees, and variable for reducers based on the length of the larger end.
These dimensions may vary slightly depending on the manufacturer and the specific type of fitting. It is important to refer to the appropriate ASTM A403 or ASME SA403 standard to ensure the proper dimensions are being used for a given application.