MM DIAMETER CHART ACTUAL SIZE ISO

Stainless steel pipes, which were coming into more common use in the mid 20th century, permitted the use of thinner pipe walls with much less risk of failure due to corrosion. Since the original schedules were created, there have been many revisions and additions to the tables of pipe sizes based on industry use and on standards from API, ASTM, and others. Also, in 1939, it was hoped that the designations of STD, XS, and XXS would be phased out by schedule numbers, however those original terms are still in common use today (although sometimes referred to as standard, extra-heavy (XH), and double extra-heavy (XXH), respectively). However these three sizes did not fit all applications. At that time only a small selection of wall thicknesses were in use: standard weight (STD), extra-strong (XS), and double extra-strong (XXS), based on the iron pipe size (IPS) system of the day. In March 1927 the American Standards Association authorized a committee to standardize the dimensions of wrought steel and wrought iron pipe and tubing.

The term NB ( nominal bore) is also frequently used interchangeably with DN.

MM DIAMETER CHART ACTUAL SIZE ISO

The European and international designation equivalent to NPS is DN ( diamètre nominal/nominal diameter/Nennweite), in which sizes are measured in millimetres, see ISO 6708. NPS is often incorrectly called National Pipe Size, due to confusion with the American standard for pipe threads, ' national pipe straight', which also abbreviates as 'NPS'. or Sch., for example – '2-inch diameter pipe, Schedule 40'). Specific pipe is identified by pipe diameter and another non-dimensional number for wall thickness referred to as the Schedule (Sched. 'Nominal' refers to pipe in non-specific terms and identifies the diameter of the hole with a non-dimensional number (for example – 2-inch nominal steel pipe' consists of many varieties of steel pipe with the only criterion being a 2.375-inch (60.3 mm) outside diameter).

Nominal Pipe Size ( NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. standard for the straight thread form on pipe (also abbreviated NPS), see National Pipe Thread. standard for pipe sizes, abbreviated NPS.

Mm diameter chart actual size