ISO Flange Centering Ring Buna-N O-Rings

These Buna-N O-rings can be used as spares or to replace the O-rings on our ISO centering ring seal assemblies. Buna-N (N674-70 compound) is black colored elastomer with a bakeout rating of 80°C and is less expensive and seals easier than lasts longer than Buna-N.

Replacement Buna-N O-rings for ISO centering rings
80 °C maximum temperature
Keep as spares for increased up-time

See All Features

Description	Compatibility	Flange Size	Inner Diameter	Thickness	Price
100761906Buna-N O-Ring, NW63 Size ISO-MF Vacuum Flange, 2-336 O-Ring Size	UNIVERSAL	NW63	2.85 in. (72 mm)	0.21 in. (5 mm)	$1.97
100761908Buna-N O-Ring, NW80 Size ISO-MF Vacuum Flange, 2-340 O-Ring Size	UNIVERSAL	NW80	3.35 in. (85 mm)	0.21 in. (5 mm)	$3.13
100761910Buna-N O-Ring, NW100 Size ISO-MF Vacuum Flange, 2-346 O-Ring Size	UNIVERSAL	NW100	4.10 in. (104 mm)	0.21 in. (5 mm)	$3.35
100761916Buna-N O-Ring, NW160 Size ISO-MF Vacuum Flange, 2-361 O-Ring Size	UNIVERSAL	NW160	5.98 in. (152 mm)	0.21 in. (5 mm)	$3.94
100761920Buna-N O-Ring, NW200 Size ISO-MF Vacuum Flange, 2-371 O-Ring Size	UNIVERSAL	NW200	8.48 in. (215 mm)	0.21 in. (5 mm)	$7.18
100761925Buna-N O-Ring, NW250 Size ISO-MF Vacuum Flange, 2-378 O-Ring Size	UNIVERSAL	NW250	10.48 in. (266 mm)	0.21 in. (5 mm)	$8.80
100761932Buna-N O-Ring, NW320 Size ISO-MF Vacuum Flange, 2-454 O-Ring Size	UNIVERSAL	NW320	12.48 in. (317 mm)	0.28 in. (7 mm)	$30
100761940Buna-N O-Ring, NW400 Size ISO-MF Vacuum Flange, 2-460 O-Ring Size	UNIVERSAL	NW400	15.48 in. (393 mm)	0.28 in. (7 mm)	$28
100761950Buna-N O-Ring, NW500 Size ISO-MF Vacuum Flange, 2-468 O-Ring Size	UNIVERSAL	NW500	19.46 in. (494 mm)	0.28 in. (7 mm)	$67
100761963Buna-N O-Ring, NW630 Size ISO-BF Vacuum Flange, 2-474 O-Ring Size	UNIVERSAL	NW630	24.94 in. (634 mm)	0.28 in. (7 mm)	$61

Notes:

Please see o-ring schematic for dimension callouts.

Specifications

Component Type
O-Ring
Series
Series 76

Flange Type
ISO-MF: (NW63 to NW500)
ISO-BF: NW630
Material
Buna-N

Features

Elastomer Seal Comparison

	Buna-N	Viton
Compound	N674-70	V747-75
Color	Black	Black
Bakeout	80°C	150°C
Benefits	Seals easier, lower cost	High temperature, lasts longer

Viton® is recommended where temperatures, chemical resistance or long installed life make it beneficial. Use Buna-N where temperatures are moderate, and installed useful life is consistent with this material. The centering ring is available in stainless steel or aluminum. Use stainless steel where chemical resistance is needed. Flanges and seals are designed to be tightened to metal to metal contact.