components in piping systems

Updated May 2026

On this website, JIS refers to Japanese industrial and technical standards used for industrial and manufacturing activities in Japan; it is similar to the American Society of Mechanical Engineers (ASME).

JIS is the Japanese industrial standard for steel pipes, steel pipe flanges, steel fittings, valves, bolts, and gaskets, among other things, concerning industrial piping systems. The standards defines dimensions, pressure ratings, materials, and marking requirements for materials used in Japanese installations and countless projects throughout Asia.

Other JIS components

When comparing JIS and e.g. ASME, the differences turn out not to be particularly significant. Pipe sizes are virtually identical, and most other components are the same as other industry standards.

The essential difference between JIS and e.g. ASME lies in the steel pipe flanges, which differ mainly in dimensions and some minor details, as a result, NO standard flange connections can be made between ASME and JIS flanges.

Regarding JIS materials..
There are NO significant differences between various JIS and ASTM material standards.

Remark(s) of the Author...

Until recently, I was not well-informed about JIS standards.. shame? . Answering questions about JIS-related issues on a regular basis was therefore not easy, so I decided to delve deeper into the Japanese industrial standard.

A specialized company in Japan helped me with various JIS standards, allowing me to gain more knowledge myself and hopefully help others who want to know more about Japanese industrial standards.

Based on what I know now, I have decided not to publish all those other JIS components for the time being, because almost everything, such as fittings, valves, bolts, gaskets, etc., is already described in other standards on this website.