Product Manual

ShopTek™ ST45, ST55, ST75 (U.S.A. & Mexico) Operation & Maintenance Manual A: Nominal Sizes
Appendix A:
88292021-240 R01
Subject to EAR, ECCN EAR99 and related export control restrictions. 75
Nominal Sizes
Metric nominal size (DN) is the nominal size for valves,
flanges and fittings as defined by ISO 6708-1980. DN
designates the size of all components in a piping system
other than components designated by outside diameters
or by thread size. For example, steel tubes are desig-
nated and ordered by outside diameter and thickness.
A metric nominal size is indicated by the letters “DN” fol-
lowed by a number without any unit of measure. For met-
ric to imperial nominal size equivalents, refer to Table A-
1: Metric to Imperial nominal sizes.
NOTE
Because DN is a round number that cannot be
measured and is only loosely related to manu-
facturing dimensions, you should only use the
DN number for reference and never for calcula-
tions.
Table A-1: Metric to Imperial nominal sizes
Metric DN
(Nominal Size)
Imperial NS
(Nominal Size)
A dimensionless designation
Designated in inches
sometimes as ND, NB or NPS
6 ⅛″
8¼″
10 ⅜″
15 ½″
20 ¾″
25 1″
32 1¼″
40 1½″
50 2″
65 2½″
80 3″