Definition Nominal Bore Of A Pipe

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.

Definition nominal bore of a pipe. Nominal bore is the approximate internal measurement across the diameter of the mouth of a pipe. Nb nominal bore is also frequently used interchangeably with nps. Nominal pipe size nps is a north american set of standard sizes for pipes used for high or low pressures and temperatures. The schedule of a pipe refers to the thickness of the walls which can have an impact on the interior diameter.

In addition to nominal pipe size the thickness of the walls is also subject to standardized measuring guidelines. Significance international regulations govern the size of pipes outward dimensions ensuring pipe is manufactured in standard sizes for easy fitting. Nominal bore is the approximate internal measurement across the diameter of the mouth of a pipe. Pipe schedule which is nothing but wall thickness of the pipe.

Od is the outside diameter of the pipe and is fixed for a given size. Nb is nominal bore of that pipe that doesn t mean that the pipe diameter inner or outer will be equal to the nb but it is an digit nearest to the out side diameter of the pipe. Nominal pipe size is the standard measurement used for pipes in north america. Nominal is used in the sense of in name only or putative in this instance.

Nb nominal bore is the european designation equivalent to nps is dn diamètre nominal nominal diameter durchmesser nach norm in which sizes are measured in millimeters. Definition of schedule number. Nominal bore nb is another equivalent designation of nps. The schedule number indicates approximate value of the expression 1000 x p s where p is the service pressure and s is the allowable stress both expressed in pounds per square inch.

The bore is the hollow center of any pipe. The standard pipe dimension tables shown above are valid for most of the pipe materials including the pipes made up of wrought iron wrought steel stainless steel polyvinyl chloride pvc and cpvc. Nominal pipe size nps is a set of standard north american sizes to designate pipe diameter and thickness for pipes that are used for low and high pressures and temperatures.