DN Pipe Flanges | McMaster-Carr

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29 Products

How to Identify and Measure Fittings

Pipe size is an industry designation, not the actual size. View information about how to measure threaded and unthreaded pipe and pipe fittings.

Low-Pressure Steel Unthreaded Pipe Flanges

Bolt two flat-surface flanges or two raised-surface flanges of the same size together with a gasket (sold separately) to create an access point in a pipe line. Flanges are for use with low-pressure applications in noncorrosive environments.

Butt-weld flanges are also known as weld-neck flanges. The flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld.

Slip-on weld flanges have no internal stop. Slide a pipe through the flange and weld on both sides.

Cap flanges are also known as blind flanges.

Metric Butt-Weld Flanges

Front

Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN 2633, DIN 86030, DIN EN 1092-1, DIN 2527
Pipe Nipples and Pipe: Use Schedule 40 steel
Fittings: Use Schedule 40 iron or steel

					Bolt Hole
Pipe Size	DN Flange Size	Wall Thick., mm	Flange OD, mm	For Bolt Dia., mm	Dia.	No. of	Bolt Circle Dia., mm	Construction	Max. Pressure	Max. Steam Pressure		Each
1	25	3.378	115	12	14	4	85	Welded	230 psi @ 72° F	180 psi @ 300° F	0000000	000000
2	50	3.912	165	16	18	4	125	Welded	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
3	80	5.486	200	16	18	8	160	Welded	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
4	100	6.02	220	16	18	8	180	Welded	230 psi @ 72° F	180 psi @ 300° F	0000000	00000

Metric Slip-On Weld Flanges

Front

Raised Surface on Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN 2633, DIN 86030, DIN EN 1092-1, DIN 2527
Pipe Nipples and Pipe: Use Schedule 40 steel
Fittings: Use Schedule 40 iron or steel

				Bolt Hole
Pipe Size	DN Flange Size	Flange OD, mm	For Bolt Dia., mm	Dia.	No. of	Bolt Circle Dia., mm	Max. Pressure	Max. Steam Pressure		Each
1	25	115	12	14	4	85	230 psi @ 72° F	180 psi @ 300° F	0000000	000000
2	50	165	16	18	4	125	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
3	80	200	16	18	8	160	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
4	100	220	16	18	8	180	230 psi @ 72° F	180 psi @ 300° F	0000000	00000

Metric Caps

Front

Raised Surface on Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN 2633, DIN 86030, DIN EN 1092-1, DIN 2527
Pipe Nipples and Pipe: Use Schedule 40 steel
Fittings: Use Schedule 40 iron or steel

				Bolt Hole
Pipe Size	DN Flange Size	Flange OD, mm	For Bolt Dia., mm	Dia.	No. of	Bolt Circle Dia., mm	Max. Pressure	Max. Steam Pressure		Each
1	25	115	12	14	4	85	230 psi @ 72° F	180 psi @ 300° F	0000000	000000
2	50	165	16	18	4	125	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
3	80	200	16	18	8	160	230 psi @ 72° F	180 psi @ 300° F	0000000	00000
4	100	220	16	18	8	180	230 psi @ 72° F	180 psi @ 300° F	0000000	00000

Low-Pressure Stainless Steel Unthreaded Pipe Flanges

Bolt two flat-surface flanges or two raised-surface flanges of the same size together with a gasket (sold separately) to create an access point in a pipe line.

Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld. Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides. Cap flanges are also known as blind flanges.

Forged flanges have better strength than cast flanges. 304 stainless steel flanges offer very good corrosion resistance, and 316 stainless steel flanges have excellent corrosion resistance.

Metric Butt-Weld Flanges—Forged

Raised Surface on Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN EN 1092-1

					Bolt Hole				304/304L Stainless Steel
Pipe Size	DN Flange Size	Construction	Flange OD, mm	For Bolt Dia., mm	Dia., mm	No. of	Bolt Circle Dia., mm	Max. Pressure	Max. Steam Pressure		Each
1	25	Seamless	115	12	14	4	85	230 psi @ 72° F	125 psi @ 300° F	0000000	0000000
2	50	Seamless	165	16	18	4	125	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
3	80	Seamless	200	16	18	8	160	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
4	100	Seamless	220	16	18	8	180	230 psi @ 72° F	125 psi @ 300° F	0000000	000000

Metric Slip-On Weld Flanges—Forged

Front

Raised Surface on Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN EN 1092-1

				Bolt Hole
Pipe Size	DN Flange Size	Flange OD, mm	For Bolt Dia., mm	Dia., mm	No. of	Bolt Circle Dia., mm	Max. Pressure	Max. Steam Pressure		Each
304/304L Stainless Steel
1	25	115	12	14	4	85	230 psi @ 72° F	125 psi @ 300° F	0000000	0000000
2	50	165	16	18	4	125	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
3	80	200	16	18	8	160	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
4	100	220	16	18	8	180	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
6	150	285	20	22	8	240	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
316/316L Stainless Steel
3	80	200	16	18	8	160	230 psi @ 72° F	145 psi @ 300° F	0000000	000000
4	100	220	16	18	8	180	230 psi @ 72° F	145 psi @ 300° F	0000000	000000

Metric Caps—Forged

Front

Raised Surface on Back

For Use With: Air, Natural Gas, Oil, Steam, Water
Specifications Met: DIN EN 1092-1

				Bolt Hole
Pipe Size	DN Flange Size	Flange OD, mm	For Bolt Dia., mm	Dia., mm	No. of	Bolt Circle Dia., mm	Max. Pressure	Max. Steam Pressure		Each
304/304L Stainless Steel
1	25	115	12	14	4	85	230 psi @ 72° F	125 psi @ 300° F	0000000	0000000
2	50	165	16	18	4	125	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
3	80	200	16	18	8	160	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
4	100	220	16	18	8	180	230 psi @ 72° F	125 psi @ 300° F	0000000	000000
316/316L Stainless Steel
1	25	115	12	14	4	85	230 psi @ 72° F	145 psi @ 300° F	0000000	000000
2	50	165	16	18	4	125	230 psi @ 72° F	145 psi @ 300° F	0000000	000000