JIS buttweld fittings are the Japanese Industrial Standards for steel butt-welding pipe fittings. Three standards cover them: JIS B2311 for fittings for ordinary use, JIS B2312 for steel butt-welding pipe fittings for pressure service, and JIS B2313 for steel plate butt-welding fittings. They are used in shipbuilding, power and process plants built to Japanese design and for Japanese equipment worldwide.
Raaj Fittings manufactures fittings to JIS dimensions at our two plants in India in carbon and stainless steel.
| Standard | Scope |
|---|---|
| JIS B2311 | Steel butt-welding pipe fittings for ordinary use, for low-pressure water, air, steam and oil |
| JIS B2312 | Steel butt-welding pipe fittings (seamless or welded from pipe) for pressure service |
| JIS B2313 | Steel plate butt-welding pipe fittings, made from plate for larger sizes |
JIS fittings use nominal sizes in "A" (mm) and "B" (inch) designations, such as 100A (4B), and JIS pipe schedules, including SCH 10S, 20S, 40 and 80 for stainless and carbon steel. Outside diameters follow JIS pipe dimensions, which match ASME pipe for most common sizes, but wall thicknesses and some fitting dimensions can differ.
JIS fittings are made in the carbon steel and stainless steel grades of the matching JIS pipe standards, such as SUS304, SUS304L, SUS316 and SUS316L stainless, or in equivalent ASTM grades where the purchaser accepts them.
Every JIS fitting is made from PMI-verified material, dimensionally inspected against the ordered standard and marked with material, size, rating and heat number. Orders are supplied with EN 10204 3.1 certificates; EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request.
JIS B2311 covers fittings for ordinary low-pressure use; JIS B2312 covers butt-welding fittings for pressure service, with stricter requirements.
JIS B2313 covers steel plate butt-welding fittings, made from plate, usually in larger sizes.
Outside diameters match for many sizes, but wall thicknesses, schedules and some dimensions differ, so order to the standard of the piping specification.
Yes, JIS-dimension fittings are available in SUS304 / SUS316 equivalent stainless steels as well as carbon steel.