What does PN stand for?

PN means “Pressure Nominale”. The PN is used as a prefix to the pressure rating of the Flanges. For example, the flange PN16 is designed to operate at up to 16 levels at 20-degree celsius. Normal scores: PN6, PN10, PN16, PN25, PN40, PN64, PN100. Following international flange standards such as ISO 7005-1 or DIN 2501, PN10, PN16, PN25, and PN40 specify both pressure classes in pressure bars and metric flange dimensions that use the metric measuring system. PN flanges developed to ANSI, AWWA, ASA, or old British specifications measured in inches will not necessarily fit with the specification of flanges.

What are DN flange Dimensions?

DN stands for ‘Diameter Nominal’. Put simply, it is a rough translation of mm from imperial sizes, assuming that an inch is 25mm. We refer to a 12″ flange as DN300, when in fact it is 304mm.

How to Measure a Flange?

• • A: INSIDE DIAMETER

    • • Measure across the center from one side of the internal hole to the opposite side of the hole.

• • B: OUTSIDE DIAMETER

    • • Measure across the center from the external edge to the other external edge of the flange.

• • C: PITCH CIRCLE DIAMETER (PCD)

    • • Measure from the center of the bolt hole to the center of the opposite bolt hole. This can also be measured from the external edge of the bolt hole to the internal edge of the opposite bolt hole.

• • D: HOLE SIZE

    • • Measure from edge to edge, across the center of a bolt hole. This will generally be slightly larger than the metric bolt being used.

• • E: THICKNESS

    • • Measure from one edge of the flat face to the other.

PN16 Flange Dimensions

DN	A	B	C	D	E	F
10	90	60	40	2	17.2	28
15	95	65	45	2	21.3	32
20	105	75	58	2.3	26.9	40
25	115	85	68	2.6	33.7	46
32	140	100	78	2.6	42.4	56
40	150	110	88	2.6	48.3	64
50	165	125	102	2.9	60.3	74
65	185	145	122	2.9	76.1	92
80	200	160	138	3.2	88.9	105
100	220	180	158	3.6	114.3	131
125	250	210	188	4	139.7	156
150	285	240	212	4.5	168.3	184
200	340	295	268	6.3	219.1	235
250	405	355	320	6.3	273	292
300	460	410	378	7.1	323.9	344
350	520	470	438	8	355.6	390
400	580	525	490	8	406.4	445
450	640	585	550	8	457	490
500	715	650	610	8	508	548
600	840	770	725	10	610	670
700	910	840	795	10	711	755
800	1025	950	900	12.5	813	855
900	1125	1050	1000	12.5	914	955
1000	1255	1170	1115	12.5	1016	1058
1200	1485	1390	1330	14.2	1219	1262
1400	1685	1590	1530	16	1422	1465
1600	1930	1820	1750	17.5	1626	1668
1800	2130	2020	1950	20	1829	1870
2000	2345	2230	2150	22	2032	2072

PN25 Flange Dimensions

DN	A	B	C	D	E	F
10	90	60	40	2	17.2	28
15	95	65	45	2	21.3	32
20	105	75	58	2.3	26.9	40
25	115	85	68	2.6	33.7	46
32	140	100	78	2.6	42.4	56
40	150	110	88	2.6	48.3	64
50	165	125	102	2.9	60.3	75
65	185	145	122	2.9	76.1	90
80	200	160	138	3.2	88.9	105
100	235	190	162	3.6	114.3	134
125	270	220	188	4	139.7	162
150	300	250	218	4.5	168.3	192
200	360	310	278	6.3	219.1	244
250	425	370	335	7.1	273	298
300	485	430	395	8	323.9	352
350	555	490	450	8	355.6	398
400	620	550	505	8.8	406.4	452
450	670	600	555	8.8	457	500
500	730	660	615	10	508	558
600	845	770	720	11	610	660
700	960	875	820	14.2	711	760
800	1085	990	930	16	813	864
900	1185	1090	1030	17.5	914	968
1000	1320	1210	1140	20	1016	1070