Flange tables

Flanges are essential when connecting valves to pipework as they make future maintenance and removal easier. Standards vary worldwide and aren’t always interchangeable, which means you need to identify which flange standards you have. 

The use of a flange table can help you identify what standard you have based on features such as nominal pressure, pitch circle diameter (PCD) or the diameter of bolts or the raised face. 

The tables below show PN flange dimensions to help you identify the standards that you have.

Do you need some help or advice with identifying your flange standards? Contact our team today. 

Scroll ↔ to view the full table

Nominal pressure	Flange diameter (mm)	PCD (mm)	No. of bolt holes	Diameter of bolts	Diameter of holes (mm)	Diameter of raised face (mm)	Height of raised face (mm)
1/2″ nominal bore (DN15)
PN6	80	55	4	M10	11	40	2
PN10	95	65	4	M12	14	45	2
PN16	95	65	4	M12	14	45	2
PN25	95	65	4	M12	14	45	2
3/4″ nominal bore (DN20)
PN6	90	65	4	M10	11	50	2
PN10	105	75	4	M12	14	58	2
PN16	105	75	4	M12	14	58	2
PN25	105	75	4	M12	14	58	2
1″ nominal bore (DN25)
PN6	100	75	4	M10	11	60	2
PN10	115	85	4	M12	14	68	2
PN16	115	85	4	M12	14	68	2
PN25	115	85	4	M12	14	68	2
1 1/4″ nominal bore (DN32)
PN6	120	90	4	M12	14	70	2
PN10	140	100	4	M16	18	78	2
PN16	140	100	4	M16	18	78	2
PN25	140	100	4	M16	18	78	2
1 1/2″ nominal bore (DN40)
PN6	130	100	4	M12	14	80	3
PN10	150	110	4	M16	18	88	3
PN16	150	110	4	M16	18	88	3
PN25	150	110	4	M16	18	88	3
2″ nominal bore (DN50)
PN6	140	110	4	M12	14	90	3
PN10	165	125	4	M16	18	102	3
PN16	165	125	4	M16	18	102	3
PN25	165	125	4	M16	18	102	3
2 1/2″ nominal bore (DN65)
PN6	160	130	4	M14	14	110	3
PN10	185	145	4	M18	18	122	3
PN16	185	145	4	M18	18	122	3
PN25	185	145	8	M18	18	122	3
3″ nominal bore (DN80)
PN6	190	150	4	M16	18	128	3
PN10	200	160	8	M16	18	138	3
PN16	200	160	8	M16	18	138	3
PN25	200	160	8	M16	18	138	3
4″ nominal bore (DN100)
PN6	210	170	4	M16	18	148	3
PN10	220	180	8	M16	18	158	3
PN16	220	180	8	M16	18	158	3
PN25	235	180	8	M20	22	162	3