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

KF Style ISO Flange Specifications A
pp
endix A: Product S
p
ecifications
36
KF Style ISO Flange Specifications
Valve Type Number 253B-
20-40-1
253B-
20-40-2
253B-
1-40-1
253B-
1-40-2
253B-
2-50-1
253B-
2-50-2
Inside Diameter (A)*
Inches
(mm)
0.779
(19.8)
0.779
(19.8)
1.270
(32.3)
1.270
(32.3)
1.888
(48.0)
2.000
(50.8)
Mounting Flange
KF-40 KF-40 KF-40 KF-40 KF-50 KF-50
Outside Diameter (B)*
Unheated
Inches
(mm)
With heater
option
Inches
(mm)
2.75
(69.9)
3.00
(76.2)
2.75
(69.9)
3.00
(76.2)
2.75
(69.9)
3.00
(76.2)
2.75
(69.9)
3.00
(76.2)
3.25
(82.6)
3.50
(88.9)
3.25
(82.6)
3.50
(88.9)
Controllable
Conductance (l/sec)
min
max
0.07
24
0.25
31
0.20
50
0.40
55
0.35
300
0.70
300
Closed Leakage
(Torr l/sec)
<10
-7
N/A <10
-7
N/A <10
-7
N/A
Flapper Seal**
Viton None Viton None Viton None
Thickness (C)*
Inches
(mm)
2.25
(57.2)
2.25
(57.2)
2.25
(57.2)
2.25
(57.2)
2.00
(50.8)
2.00
(50.8)
Overall Height
Unheated
Inches
(mm)
With heater
option
Inches
(mm)
8.64
(219.5)
8.81
(223.8)
8.64
(219.5)
8.81
(223.8)
8.64
(219.5)
8.81
(223.8)
8.64
(219.5)
8.81
(223.8)
9.14
(232.2)
9.31
(236.5)
9.14
(232.2)
9.31
(236.5)
No. of Bolt Holes
N/A N/A N/A N/A N/A N/A
Bolt Hole Diameter (D)
N/A N/A N/A N/A N/A N/A
Bolt Circle Diameter
N/A N/A N/A N/A N/A N/A
Flange O-ring groove
ID
N/A N/A N/A N/A N/A N/A
* Refer to Figure 2, page 24.
** Where Viton is used, other materials are available; consult factory.