Typical pipe diameters – inches, mm, DIN, ISO, PE

When selecting pumps, discussing pipelines (most often discharge pipelines) is unavoidable. To ensure we understand each other, we must use the same names. For some, a 50 mm pipe means PE50 (50 mm outside diameter); for others, DN50 (e.g. stainless steel Ø60.3×2); and for still others, approximately 50 mm inside diameter (i.e. PE63×5.8), because this is what we use to calculate pipeline losses. Below, we present a table of typical pipes according to various materials and standards: metric and imperial. When speaking with a consultant, please provide the exact diameter of the pipeline being discussed.

DN	Gauge	DIN	ISO	PE
6	⅛”	-	10.00 mm	-
8	¼”	-	13.50 mm	-
10	⅜”	14.00 mm	17.20 mm	PE16
15	½”	20.00 mm	21.30 mm	PE20
20	¾”	25.00 mm	26.90 mm	PE25
25	1”	30.00 mm	33.70 mm	PE32
32	1¼”	38.00 mm	42.40 mm	PE40
40	1½”	44.50 mm	48.30 mm	PE50
50	2”	57.00 mm	60.30 mm	PE63
65	2½”	76.10 mm	76.10 mm	PE75
80	3”	88.90 mm	88.90 mm	PE90
100	4”	108.00 mm	114.30 mm	PE110
125	5”	133.00 mm	139.70 mm	PE140
150	6”	159.00 mm	168.30 mm	PE160