BS EN 1092-1 PN16 Flange Dimensions

BS EN 1092-1 PN16 flange dimensions provide dimensional and bolting information for PN-designated steel flanges used with pipes, valves, fittings and other piping components. The tables below cover nominal sizes from DN10 to DN1600 and include flange outside diameter, thickness, bore and hub dimensions together with bolt circle, bolt-hole and bolt-size information.

Standard reference: BS EN 1092-1 specifies requirements for PN-designated circular steel flanges. This RoyMech page is intended as a convenient engineering reference and does not reproduce all requirements, flange types, tolerances, materials, pressure/temperature ratings or manufacturing provisions contained in the standard. For specification, manufacture, conformity or safety-critical design, consult the applicable current edition of BS EN 1092-1.

BS EN 1092-1 PN16 Flange Reference

Flange Dimension Symbols

DN	Nominal size
D	Flange outside diameter
A	Outside diameter of neck
B1	Bore dimension for the flange forms represented by this table
C1	Plate flange thickness
C2	Weld-neck and boss flange thickness
N1	Weld-neck diameter
N2	Boss diameter
R	Corner radius
H1	Boss flange length
H2	Weld-neck flange length
H3	Neck length
d1	Facing diameter shown in the diagram/table
f1	Facing height shown in the diagram/table
S	Neck thickness

Common BS EN 1092-1 Flange Types

BS EN 1092-1 covers considerably more flange configurations than are represented by the dimensional diagram and table on this page. Examples referenced in the source material for this page include:

• Type 01 – plate flange
• Type 02 – loose plate flange used with a suitable collar or lapped pipe end
• Type 04 – loose flange for use with a weld-neck collar
• Type 05 – blind flange
• Type 11 – weld-neck flange
• Type 12 – hubbed slip-on flange
• Type 13 – threaded flange
• Type 21 – integral flange

The standard contains additional flange and collar types and the dimensional requirements depend on the particular configuration. The table below should therefore be used with an understanding of the flange form being specified or identified.

Flange Facings

The diagram and dimensional data on this page principally represent a Type B raised face. BS EN 1092-1 also defines other facing configurations. The correct facing is important because it affects the gasket arrangement and compatibility of the completed flange joint.

Engineering note: Two flanges should not be assumed to be compatible simply because they have the same DN and PN designation. Check the applicable standard, flange type, facing, outside dimensions, drilling, materials, gasket arrangement and service requirements.

Understanding DN and PN

DN is the nominal size designation used for piping components. It identifies a standardised component size but should not be interpreted as a direct measurement of the pipe bore.

PN is a nominal pressure designation. PN16 identifies the flange pressure designation but does not mean that every PN16 flange has a universal allowable working pressure of exactly 16 bar under all operating conditions. Permissible pressure depends on factors including flange material and temperature and should be determined from the applicable pressure/temperature ratings and design requirements.

How to Use the PN16 Flange Table

Select the required nominal size DN in the first column and read across the row to obtain the corresponding flange dimensions. All dimensions in the table are in millimetres.

The separate PN16 drilling table below provides the bolt circle diameter, bolt-hole diameter, number of holes and nominal bolt size.

Reference use: The tables are suitable as a convenient engineering reference and for preliminary dimensional work. They should not be treated as a substitute for the complete standard where tolerances, materials, pressure/temperature capability, manufacture, inspection or conformity requirements are important.

BS EN 1092-1 PN16 Flange Dimensions

All dimensions are in mm.

DN	D	C1	C2	H1	H2	H3	R	A	N1	N2	B1	d1	f1	S
10	90	14	14	20	35	6	4	17,2	28	30	18	40	2	1,8
15	95	14	14	20	35	6	4	21,3	32	35	22	45	2	2,0
20	105	14	14	24	38	6	4	26,9	39	45	27,5	58	2	2,3
25	115	16	16	24	38	6	4	33,7	46	52	34,5	68	2	2,6
32	140	18	16	26	40	6	6	42,4	56	60	43,5	78	2	2,6
40	150	18	16	26	42	7	6	48,3	64	70	49,5	88	2	2,6
50	165	19	18	28	45	8	6	60,3	75	84	61,5	102	2	2,9
65	185	20	18	32	45	10	6	76,1	90	104	77,5	122	2	2,9
80	200	20	20	34	50	10	8	88,9	105	118	90,5	138	2	3,2
100	220	22	20	40	52	12	8	114,3	131	140	116	158	2	3,6
125	250	22	22	44	55	12	8	139,7	156	168	141,5	188	2	4,0
150	285	24	22	44	55	12	10	168,3	192	195	170,5	212	2	4,5
200	340	26	24	44	62	16	10	219,1	235	246	221,5	268	2	5,6
250	405	29	26	46	70	16	12	273	292	298	276,5	320	2	6,3
300	460	32	28	46	78	16	12	323,9	344	350	327,5	378	2	7,1
350	520	35	30	57	82	16	12	355,6	390	400	359	438	2	8,0
400	580	38	32	63	85	16	12	406,4	445	456	411,0	490	2	8,0
450	640	42	40	68	87	16	12	457,0	490	502	462,0	550	2	8,0
500	715	46	44	73	90	16	12	508,0	548	559	513,5	610	2	8,0
600	840	52	54	83	95	18	12	610,0	652	658	616,5	725	2	8,8
700	910	-	36	83	100	18	12	711,0	755	760	-	795	2	8,8
800	1025	-	38	90	105	20	12	813,0	855	864	-	900	2	10,0
900	1125	-	40	94	110	20	12	914,0	955	968	-	1000	2	10,0
1000	1255	-	42	100	120	22	16	1016,0	1058	1072	-	1115	2	10,0
1200	1485	-	48	-	130	30	16	1219,0	1262	-	-	1330	2	12,5
1400	1685	-	52	-	145	30	16	1420,0	1465	-	-	1530	2	14,2
1600	1930	-	58	-	160	35	16	1620,0	1668	-	-	1750	2	16,0
DN	D	C1	C2	H1	H2	H3	R	A	N1	N2	B1	d1	f1	S

BS EN 1092-1 PN16 Flange Bolting

The following table provides the drilling and nominal bolt sizes associated with the PN16 flange dimensions above.

K = Bolt circle diameter (PCD), L = bolt-hole diameter, No. = number of bolt holes, Size = nominal metric bolt size.

All dimensions are in mm.

DN	K	L	No	Size
mm	mm	mm	-	mm
10	60	14	4	M12
15	65	14	4	M12
20	75	14	4	M12
25	85	14	4	M12
32	100	18	4	M16
40	110	18	4	M16
50	125	18	4	M16
65	145	18	8**	M16
80	160	18	8	M16
100	180	18	8	M16
125	210	18	8	M16
150	240	22	8	M20
200	295	22	12	M20
250	355	26	12	M24
300	410	26	12	M24
350	470	26	16	M24
400	525	30	16	M27
450	585	30	20	M27
500	650	33	20	M30
600	770	36	20	M33
700	840	36	24	M33
800	950	39	24	M36
900	1050	39	28	M36
1000	1170	42	28	M39
1200	1390	48	32	M45
1400	1590	48	36	M45
1600	1820	56	40	M52
DN	K	L	No	Size

DN65 note: The source table identifies the DN65 eight-hole entry with a special qualification. Where a design depends on an alternative drilling arrangement, verify the requirement against the applicable edition of BS EN 1092-1 rather than assuming interchangeability.

Frequently Asked Questions

What is BS EN 1092-1?

BS EN 1092-1 specifies requirements for PN-designated circular steel flanges for pipes, valves, fittings and accessories. It covers flange types and facings together with requirements including dimensions, tolerances, bolting, materials and pressure/temperature ratings.

What does PN16 mean?

PN16 is a nominal pressure designation. It should not be interpreted as a universal maximum working pressure of 16 bar because allowable pressure depends on factors including flange material and operating temperature.

What does DN mean on a flange?

DN is the nominal size designation used for the flange and associated piping components. It identifies a standardised component size and is not a direct measurement of the actual pipe bore.

Are BS EN 1092-1 and ASME flanges interchangeable?

Interchangeability should not be assumed. PN-designated BS EN 1092-1 flanges and class-designated ASME flanges use different systems of dimensional and pressure designation. The flange dimensions, drilling, facing, materials, gasket arrangement and applicable pressure/temperature ratings should be checked for the specific joint.

What should be checked when selecting a PN16 flange?

Check the required DN, flange type, facing, material, pipe connection, drilling, gasket arrangement, operating temperature and design pressure. The applicable pressure/temperature rating and any project or regulatory requirements should also be confirmed before final specification.

See Also

• BS4504 PN16 Flanges
• BS4504 PN25 Flanges
• BS4504 PN40 Flanges
• BS EN 1092-1 PN25
• BS EN 1092-1 PN40
• BS 1600 Pipes
• BS3600 Pipes
• Pipe Threads

Standard Reference

For definitive requirements consult the current edition of BS EN 1092-1, Flanges and their joints – Circular flanges for pipes, valves, fittings and accessories, PN designated – Steel flanges.