Double-eccentric metal-to-metal sealed butterfly valve

Summary

Flange double-eccentric metal-to-metal sealed butterfly valve is operated by worm gear to decelerate to drive the disc to rotate within 90°.It can be applied to cut off or regulate the flow of media. The valve can be actuated by operating lever, handle wheel, electric actuator or pneumatic actuator. Underground valve can be operated by an extended spindle. No matter operated by electric actuator or pneumatic one, positions where the valve is opened and closed are all equipped with limit switches and indicating devices that synchronically show the opening state of the disc.

Structure:

Being double eccentric, when opened, the sealed ring of the disc is automatically off-seated after only a little degree of opening movement. The sealed ring completely bears no external pressure, which helps the valve keep longer life.

 Butterfly valve has the capability of bi-directional sealing, which achieves no leakage in both primary and secondary directions, especially applicable to underground water-supplying network of pipes with circular multi-sources. If only unidirectional media, when installing the valve, the primary direction is of priority.

The position of sealed ring can be adjusted in all directions to modulate the compression of the sealing, which makes the valve able to be operated by minimum torque.

The base ring of the body and the sealed ring of the disc all employ stainless steel of excellent quality, which are competent of high temperature and anti-corrosion and long service life. The sealed structure of the valve uses divided-body design, dependable interchangeability, easy to apply and maintain.

As to those valves whose DN is equal or larger than 1200mm, the disc applies the flying-disc design with a result of light weight, high rigidity, powerful strength, small flow–resistance and low loss of pressure.

The stem and disc use a positioning pattern of non-penetration and pin–offset to avoid shearing and abrasion of the spline caused by frequent shifting of the upper stem and to prevent abnormal opening and closing of the valve.

Between the stem and the body “o” ring , a kind of environmentally-protecting rubber is applied, which not only achieves no maintenance but also reliable sealing, meanwhile, overcomes potential leakage when stuffing and sealing as well as prevents stuffing’s pollutions of the water.

Technical characteristics:

Automatic assembly and coating product line and developed process-flow ensure the outstanding ability of anti-corrosion and flawless appearances of products.

Anti-corrosion performance:

Inside and outside surfaces of the body are coated with electrostatic epoxy resin powder. The coating is even and firm with good adhesion and excellent anti-corrosion.

Sanitary standard:

Non-toxic epoxy resin powder used comply with sanitary standard GB/T 17219-1998.

The coated resin is in accordance with standards of potable water

Applying area:

The valve can be used in potable water system, water supply and drainage, heat supply, gas, metallurgical industry, energy system and pipeline and so on.