DIN 2634 PN25 Weld Neck Flange

DIN 2634 PN25 Weld Neck Flange – Specification

Standard: DIN 2634
Type: Weld Neck Flange (WN)
Pressure Rating: PN 25 (25 bar at 20°C ≈ 362 psi)
Nominal Sizes: DN 10 to DN 600 (typical)
Facing: Form B (Raised Face), Form C (Male/Female) optionally available
Welding: Butt-weld connection with beveled neck

DIN 2634 flange Description

DIN 2634 defines weld neck flanges designed for medium pressure PN 25 applications. These flanges have a long tapered hub which is butt-welded to the pipe, providing excellent strength and resistance to fatigue, thermal cycling, and vibration.

Download DIN 2634 standard pdf

Dimensions of DIN2634 PN25 Welding Neck Flange

Dimension and weight of DIN2634 PN25 Welding Neck Flange

Pipe Parameter	d1		Flange Dimension				Neck Size				Hub Size		Screw		Approx. Flange Weight
DN	ISO	DIN	D	b	k	h1	d3	s	r	h2	d4	f	No. of Holes	d2	KG/PCS
10	–	14	90	16	60	35	25	1.8	4	6	40	2	4	14	0.67
	17.2	–	90	16	60	35	28	1.8	4	6	40	2	4	14	0.66
15	–	20	95	16	65	38	30	2	4	6	45	2	4	14	0.75
	21.3	–	95	16	65	38	32	2	4	6	45	2	4	14	0.75
20	–	25	105	18	75	40	38	2.3	4	6	58	2	4	14	1.07
	26.9	–	105	18	75	40	40	2.3	4	6	58	2	4	14	1.07
25	–	30	115	18	85	40	42	2.6	4	6	68	2	4	14	1.29
	33.7	–	115	18	85	40	46	2.6	4	6	68	2	4	14	1.28
32	–	38	140	18	100	42	52	2.6	6	6	78	2	4	18	1.88
	42.4	–	140	18	100	42	56	2.6	6	6	78	2	4	18	1.86
40	–	44.5	150	18	110	45	60	2.6	6	7	88	3	4	18	2.1
	48.3	–	150	18	110	45	64	2.6	6	7	88	3	4	18	2.08
50	–	57	165	20	125	48	72	2.9	6	8	102	3	4	18	2.81
	60.3	–	165	20	125	48	75	2.9	6	8	102	3	4	18	2.78
65	76.1	–	185	22	145	52	90	2.9	6	10	122	3	8	18	3.61
80	88.9	–	200	24	160	58	105	3.2	8	12	138	3	8	18	4.62
100	–	106	235	24	190	65	128	3.6	8	12	162	3	8	22	6.42
	114.3	–	235	24	190	65	134	3.6	8	12	162	3	8	22	6.27
125	–	133	270	26	220	68	155	4	8	12	188	3	8	26	8.83
	139.7	–	270	26	220	68	162	4	8	12	188	3	8	26	8.61
150	–	159	300	28	250	75	182	4.5	10	12	218	3	8	26	11.67
	166.3	–	300	28	250	75	192	4.5	10	12	218	3	8	26	11.29
175	193.7	–	330	28	280	75	218	5.6	10	15	248	3	12	26	13.11
200	219.1	–	360	30	310	80	244	6.3	10	16	278	3	12	26	16.61
250	–	267	425	32	370	88	292	7.1	12	18	335	3	12	30	23.99
	273	–	425	32	370	88	298	7.1	12	18	335	3	12	30	23.48
300	323.9	–	485	34	430	92	352	8	12	18	395	4	16	30	30.74
350	355.6	–	555	38	490	100	398	8	12	20	450	4	16	33	47.2
	–	368	555	38	490	100	398	8	12	20	450	4	16	33	44.22
400	406.4	–	620	40	550	110	452	8.8	12	20	505	4	16	36	61.69
	–	419	620	40	550	110	452	8.8	12	20	505	4	16	36	57.88
500	508	–	730	44	660	125	558	10	12	20	615	4	20	36	89.57
600	610	–	845	46	770	125	660	11	12	20	720	5	20	39	114.96
700	711	–	960	46	875	125	760	12.5	12	20	820	5	24	42	139.5
800	813	–	1085	50	990	135	865	14.2	12	22	930	5	24	48	188.71
900	914	–	1185	54	1090	145	968	16	12	24	1030	5	28	48	231.48
1000	1016	–	1320	58	1210	155	1070	17.5	16	24	1140	5	28	56	303.52

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DIN 2634 Flange Materials

DIN 2634 flanges are commonly manufactured from:

• Carbon Steel: C22.8 (1.0460), P245GH, P250GH
• Alloy Steel: 16Mo3, 13CrMo4-5
• Stainless Steel: 1.4301 (304), 1.4404 (316L), 1.4571 (316Ti)
• Copper Nickel Alloys: For marine applications

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DIN 2634 Flange Pressure-Temperature Ratings

• PN 25 corresponds to 25 bar at 20°C.
• Ratings decrease with temperature as per DIN EN 1092-1.

Why Choose our DIN 2634 PN25 Weld Neck Flanges?

• Superior Strength: The weld neck design offers the highest integrity connection type for PN25 pressure class.
• Reduced Stress Concentration: Smooth transition from flange to pipe minimizes fatigue and potential failure points.
• Leak Prevention: Reliable RF sealing surface ensures secure, long-lasting joints.
• Wide Compatibility: Standard dimensions ensure compatibility with PN25 valves, fittings, and equipment per DIN/EN standards.
• Industrial Grade: Carbon steel construction provides proven performance in demanding sectors