BELLOWS SEALED VALVES
FOR ULTRA HIGH VACUUM SYSTEM

                                                                                                              

Size 6 mm 12 mm 25 mm 63 mm 100 mm
Type Gate Gate Gate/ Rt. angle Butterfly Gate/ Butterfly
Mounting Flange KF KF CF/KF CF CF
Operation Manual Manual/ automatic Toggle/ automatic Manual/ automatic Manual/ automatic
Bakebility
(open condition)
1500C 1500C 3000C/ 1500C 3000C 3000C
Overall Leak Tightness 1x10-9 cc/sec 1x10-10 
cc/sec
1x10-11 cc/sec 1x10-11 cc/sec 1x10-11 cc/sec

Introduction 

Vacuum valves are indispensable components of any vacuum system extensively used in research and development work and in many process lines. These facilitate isolation of a part of the system during servicing, maintenance, loading of samples etc.

Description 

Both angle and in-line valves are bellows sealed to ensure high leak tightness during their operation. In-line type includes gate and butterfly valves and angle type a right angle valve. Gate type is available in 6 mm and 12 mm sizes, which are `High Vacuum’ compatible and 25 mm size, which is `Ultra High Vacuum’ compatible. Butterfly type has the largest open conductance and is highly compact in size. It can also be used as a throttle or conductance control valve. Gate valves being fully open and in-line valves offer unrestricted opening and are ideally suited for applications such as beam transportation systems and load locks for sample introduction. Right angle valves are used for roughing and baking, venting and leak testing applications.

The vacuum valve is made of three members namely: 

i) Valve body 
ii) Sealing plate and 
iii) Trim or actuating mechanism. 

i) Valve body
Construction of material is SS-304. It has a flange on top for mounting the actuacting mechanism. The end configuration conforms to ISO standard such as Klein flange or Conflat.

ii) Sealing plate 
This is a disc/ flapper plate/ wedge shaped piece

iii) Actuating mechanism 
Screw type 
All parts prior to assembly need to be thoroughly cleaned & dried. 


Raw materials

All main parts -  SS 304
Bellows -  SS-316 L or 321
Plate / Body Seal -  Soft Viton `O' ring


For details contact :

    Head, Technology Transfer & Collaboration Division,
    BHABHA ATOMIC RESEARCH CENTRE,
    TROMBAY, MUMBAI - 400 085
    Tel : 091-022-25505337/25593897
    Fax : 091-022-25505151
    Email : headttcd@barc.gov.in