JIS, DIN or ANSI? How to identify a marine valve before you order

KH Marine Trading LLC · 12 November 2026

Why it matters

A replacement valve has to bolt to the existing pipe flanges. JIS, DIN and ANSI flanges of the same nominal size have different outside diameters, bolt circles and bolt counts, so a valve to the wrong standard usually will not fit without changing the pipework.

Start with the nameplate or casting marks

Most valves have the rating and size cast into the body or on a tag. JIS valves are usually marked with a K rating such as 5K, 10K or 16K and a size in A, for example 50A. DIN valves are marked PN6, PN10, PN16 or higher, with the size as DN, for example DN50. ANSI/ASME valves are marked by class, such as 150 or 300, with the size in inches.

If there is no readable marking

Measure the flange outside diameter, the bolt circle diameter (centre of one bolt hole to the centre of the opposite one), the number of bolt holes and the bolt hole size. These four measurements are usually enough to identify the standard and rating. A clear photo with a tape measure across the flange also helps.

Note the body material too. Bronze bodies are common on seawater lines, while cast iron and cast steel are common on fuel, oil and bilge service.

What to send with your enquiry

Send the valve type, the standard and rating if known, the size, the body material, the end connection and a photo of the nameplate or the old valve. Add the vessel name and any certificate requirement. With that, a supplier can match the valve or explain any differences in an alternative.