Flange, Gasket and Tube Dimensions

Schematic drawings and dimensions of suitable flanges, gaskets and flanges with tube sockets.

Flange dimensions

Schematic drawing CF flanges
Schematic drawing of the standard UHV mounting flange, ConFlat (CF) style

UHV Flange

Nominal outside diameter
O.D.
Flange thickness
d
Bolt circle
L
No. bolts

Bolt hole
H
Knife edge
S
Seal recess
D
[inch][mm][mm][mm][mm][mm][mm]
DN10CF1.025.06.017.563.310.513.5
DN16CF1.3333.87.027.064.418.321.4
DN25CF2.1254,011.541.346.827.733.0
DN40CF2.7569.912.558.766.841.948.3
DN50CF3.3885.716.072.488.455.961.8
DN63CF4.50114.317.092.288.477.282.5
DN75CF4.62117.417.5102.3108.485.291.6
DN100CF6.00152.419.5130.3168.4115.3120.6
DN125CF6.75171.521.0151.6188.4136.3141.8
DN150CF/DN160CF*
8.00203.221.0181.0208.4166.1171.4
DN200CF10.00254.024.0231.8248.4216.9222.2
DN250CF12.00304.824.0284.0328.4267.5273.1
DN275CF13.25336.628.0306.33010.8288.2294.4
DN300CF14.5368.328.0338.13210.8320.0326.4
DN350CF16.5419.128.0388.93610.8373.0376.7
DN400CF18.5469.928.0437.94010.8419.0424.4

* DN150CF and DN160CF are valid names for the same flange size.

Data quoted from ISO 3669:2020(E).

Gasket dimensions

Schematic drawing Gaskets for CF flanges
Schematic drawing of the standard gasket made of OFHC-Cu or silver-plated OFHC-Cu, suitable for UHV flanges

Gasket
Outside diameter
O.D.
Tolerance
Inside diameter
I.D.
Gasket thickness
d
[mm][mm][mm][mm]
DN10CF13.30 - 0.28.42±0.1
DN16CF21.316.22±0.1
DN25CF32.925.22±0.1
DN40CF48.239.22±0.1
DN50CF61.751.12±0.1
DN63CF82.472.02±0.1
DN75CF91.576.42±0.1
DN100CF120.50 - 0.3101.72±0.1
DN125CF141.7127.32±0.1
DN150CF / DN160CF *
171.3152.52±0.1
DN200CF222.1203.32±0.1
DN250CF272.90 - 0.5254.22±0.1
DN275CF294.3276.02±0.1
DN300CF326.2302.02±0.1
DN350CF376.5356.52±0.1
DN400CF423.9405.02±0.1

* DN150CF and DN160CF are valid names for the same flange size .

Data for outside diameter O.D. and tolerance quoted from ISO 3669:2020(E).

Common tube dimensions

Schematic drawing flange-tube-dimensions
Schematic drawing of CF flange with tube socket

UHV FlangeFlange dimensionsTube dimensions
Nominal outside diameter
O.D.
Nominal outside diameter
O.D.
Wall thickness
T
Inner diameter
I.D.
[inch][mm][inch][mm][mm][mm]
DN16CF1.3333.80.7519.02.015.0
DN40CF2.7569.91.538.01.535.0
1.6141.01.538.0
1.6742.41.639.2
DN50CF3.3885.72.1354.02.050.0
DN63CF4.5114.32.563.51.859.9
2.7670.02.066.0
2.9976.02.072.0
DN100CF6.0152,44.1104.02.0100.0
DN160CF8.0203.26.06154.02.0150.0
DN200CF10.0254.08.0204.02.0200.0
DN250CF12.0308.410.0254.02.0250.0

Please note that according to the standard, the tubes may deviate between 1 mm and 3 mm in outer diameter and 0.5 mm in wall thickness.