Expansion Joint for High Voltage Apparatus

Structure Diagram

Technical Data Sheet

Design Pressure：≤0.75Mpa

Design Temperature：-35℃～150℃

Axial Movement：-20mm～20mm

Lateral Movement：-10mm～10mm

Medium ：Sulfur Hexafluoride Gas or other gas of arc extinction and insulation. 

Cycle Life: Above 10000 times

Performance & Characteristic 

As a connect unit between the covers of two adjacent equipment , Expansion Joint for High Voltage Apparatus mainly used for adjusting the installation, compensate the relative displacement and the movement caused by Expansion and Contraction. General expansion joints always used under the condition of High Stress (Namely, large movement), but this expansion joint always used under the condition of Low Stress (Namely, small movement).  

As the holder of the composite apparatus can’t bear much pressure, so the structure should be designed to Pressure Balance Type so that the expansion joints can balance the force produced by inside pressure rely on the elastic force of the disc spring to reduce the pressure on the holder. The composite apparatus are full of expensive media of SF6 gas, annual air leakage ≤1％,or it will lower the reliability of the products when it operating, if seriously, it will lead to the power cut and the overhaul of the whole system, so the require to the gas tightness is pretty high.  

This expansion joint used as an electric elements, require the inner surface is very smooth and no cusp, or there maybe electric discharge, influence the insulating property of the products.  

Variety

Form of Structure

Device of Pressure Balance

Installation Compensator

Bellows welded onto the flange

            —

Bellows welded onto the Tube Ends and the Tubes Ends welded onto the flange.

            —

Temperature Compensator

Bellows welded onto the flange

Disc Spring/No device of Pressure Balance

Bellows welded onto the Tube Ends and the Tubes Ends welded onto the flange.

Disc Spring/No device of Pressure Balance

Bellows welded onto the Fanstone Flange

Disc Spring/No device of Pressure Balance

Pressure Balance Bellows

Self Balance of this structure

                                                   Test Methods before delivery

Test of Performance

Welding Joint

Physical Dimension

Tolerance of the dimension

Axial Spring Rate

Test of Compensation Rate

Pressure Test

Pressure Stress Test

Test of the stabilization

Test of the Air Tightness

Test of Cycle Life

Test of bursting pressure

Air Tightness Test to the
Sulfur Hexafluoride Gas