Concentric butterfly pneumatic valve, compares the single eccentric adjustment structure of the pneumatic valve

in the first place, concentric butterfly pneumatic valve

concentric butterfly pneumatic valve pneumatic valve stem axis, disc center, the body's centre of gravity in the same position. Its simple structure, easy fabrication, rubber lining butterfly pneumatic valve typically belong to that kind of structure now. The disadvantage is that the butterfly plate and remain the state of compression pneumatic seat from scratch, from big, wear resistance. It is because of these defects, the butterfly pneumatic valve adopts is flexible, in the form of the basic structure of fluorine rubber or soft plastic seal. But it is limited to the temperature.

2, single eccentric butterfly pneumatic valve

to solve the problem of concentric butterfly extrusion of pneumatic valve and pneumatic valve disc problem, the resulting single eccentric butterfly pneumatic valve seat, use dry axis deviated from the structure of disc center, the butterfly is no longer a panel on the bottom of the axis of rotation, dispersion, thus reducing the butterfly plate at the bottom of the extrusion with the pneumatic valve seat. However, due to the pneumatic valve and pneumatic valve switch seats in the scratch phenomenon in the process of single eccentric structure and no similar scope and concentric butterfly pneumatic valve application disappear, so it is small.

3, double eccentric butterfly pneumatic valve

double eccentric butterfly pneumatic valve in single eccentric butterfly valve forms the basis for further improvement is one of the most widely used double eccentric butterfly pneumatic valve. Its structure both in the stem axis deviation from the center of the disc, but also off the body's centre of gravity. Pneumatic valve pneumatic double eccentric butterfly valve plate effect can be quickly turned to leave the seat, greatly eliminates unnecessary pneumatic seat discs and excessive compression, scratches phenomenon, reduce the resistance from the public, reduce wear and improve the seat life. Greatly reduce the scratch, but also makes the double eccentric metal seal butterfly pneumatic valve, can also be used to improve the high temperature butterfly pneumatic valve. But, this is the butterfly plate and pneumatic valve seat sealing surface line contact, through the disc compression elastic pneumatic valve seat sealing effect caused by the deformation, which is very closed position ( Especially the metal pneumatic seat request, because of its seal cap principled position) , carrying capacity, which is why people think that the traditional high pressure pneumatic valve intolerance phenomenon, reasons of the leakage.

4, triple eccentric butterfly pneumatic valve

high temperature, you must use a seal, but leakage; Zero leakage, must use the soft seal, but not resistant to high temperature. Double eccentric butterfly pneumatic valve, in order to overcome this contradiction, but also for the third time eccentric butterfly pneumatic valve. The location in the double eccentric shaft, eccentric structure and disc sealing surface of cone cylinder axis deviation in the body axis, which is the surface, after the third eccentric, the CD is no longer true circular sealing strip, but the oval, the sealing surface, thus the shape of the asymmetric, and on the other side of the tilting body axis parallel to the centerline.

this is the third most important is fundamentally changing the way the characteristics of eccentric seal structure, the position is no longer sealed, but the torsion seal, which is not to rely on the elastic deformation of pneumatic valve seat, relying instead on complete contact pressure pneumatic valve seat sealing effect achieved, therefore, in a metal pneumatic seat with one action can solve the problem of zero leakage, because the contact area is directly proportional to the pressure and medium pressure in high pressure, high temperature resistant, also solved.