MKS 253B-2-2-2 - NW Style ISO Flange Specifications

Appendix A: Product Specifications NW St
y
le ISO Flan
g
e S
p
ecifications
37
NW Style ISO Flange Specifications
Valve Type Number 253B-
60-63-1
253B-
60-63-2
253B-
3-80-2
253B-
4-100-2
253B-
6-160-2
253B-
8-200-2
253B-
10-250-2
Inside Diameter (A)*
Inches
(mm)
2.362
(60.0)
2.362
(60.0)
3.000
(76.2)
3.875
(98.4)
5.750
(146.1)
7.650
(194.3)
9.700
(246.4)
Mounting Flange
NW-63 NW-63 NW-80 NW-100 NW-160 NW-200 NW-250
Outside Diameter (B)*
Inches
(mm)
5.95
(151.1)
5.95
(151.1)
5.95
(151.1)
7.40
(188.0)
8.90
(226.1)
11.22
(285.0)
13.19
(335.0)
Controllable
Conductance (l/sec)
min
max
TBD
TBD
0.80
375
1.00
500
1.50
900
TBD
TBD
TBD
TBD
TBD
TBD
Closed Leakage
(Torr l/sec)
<10
-7
N/A N/A N/A N/A N/A N/A
Flapper Seal**
Viton None None None None None None
Thickness (C)*
Inches
(mm)
0.81
(20.6)
0.81
(20.6)
0.81
(20.6)
0.94
(23.9)
0.94
(23.9)
0.94
(23.9)
0.94
(23.9)
Overall Height
Inches
(mm)
10.79
(274.1)
10.79
(274.1)
10.79
(274.1)
12.24
(310.9)
13.74
(349.0)
16.06
(407.9)
18.03
(458)
No. of Bolt Holes
448881212
Bolt Hole
Diameter (D)*
Inches
(mm)
0.35
(8.89)
0.35
(8.89)
0.35
(8.89)
0.35
(8.89)
0.43
(10.9)
0.43
(10.9)
0.43
(10.9)
Bolt Circle Diameter
Inches
(mm)
4.330
(110.0)
4.330
(110.0)
4.920
(125.0)
5.710
(145.0)
7.870
(199.9)
10.240
(260.1)
12.200
(309.9)
Flange O-ring groove
ID
N/A N/A N/A N/A N/A N/A N/A
* Refer to Figure 3, page 24.
** Where Viton is used, other materials are available; consult factory.