CNC machine tools ,large vertical lathes, drill press, milling lathe grinding machine , Welding machine , separate metal working workshops and many general machine tool etc.
Material analysis, PMI Material analysis. Chemical analysis. Low temperature test, Tensile Test ,Impact test, Hardness test. Wall thickness test, roughness test. Torque test. NDT Inspection (MT,PT,UT,RT). HIC test ,SSC test . Intercrystalline corrosion Test ,Uniform corrosion Test.
The company is the first one to pass ISO 9001(2008),ISO 14001 ,OHAS 18001 international quality system certificate, China pressure pipe safety registration certificate (AZ), European Union safety registration certificate (CE0036), and American Petroleum Institute Certificate (API 6D) and (API607) .
We are one of the member unit of China Valve Association as well as China Gas Association, member unit of first class supplying network of CNPC and member unit of fittings supplying network of State Power Corporation.
EDVC VALVE CO.,LTD.is a specialized in valve manufacturing enterprise with more than 15 years of history.We main produce Top Entry Ball Valve, Fully Welded Ball Valve, Arc Valve, Aluminum Bronze Valve, Automatic Recirculation Valve, Orbit Ball Valve, Safety Valve, Globe Valve, Tilting Disc Check Valve and Rising Stem Ball Valve etc.
The products have been exported to Austria, France, Germany, United Kingdom ,America, Middle East and Asia, Africa . areas and countries. Moreover, the products are widely used in the fields of oil & gas, Oil refinery, Petrochemical,power station ,Sewage treatment, pharmacy, Paper mills, pipeline industry , mining industry , chemical industry and environmental protection.
We are a professional manufacturer of valves in China, with the aim of "providing the first class products and services". On behalf of all of the members at EDVC Valve, we thank you for the opportunity to earn your business.
When the valve is closed, first rotate the hand wheel to rotate the cock and the sealing slide by 90°, and then the cock moves downwards. With the movement of the cock, the sealing slide is pushed to the cover of the inner cavity of the valve until the elastic sealing ring is evenly squeezed to The upper and lower ends of the valve hole form a seal.
This is a method to completely isolate the pipelines at both ends through two shut-off valves and a relief valve in the middle. Closing the two main valves and opening the relief valve can improve the safety of the system. If the first valve leaks, the leaked medium can be led out by the opened relief valve.
When the valve is opened, first rotate the handwheel to lift the cock and pull the sealing slide back from the sealing surfaces on both sides of the valve body. When the sliding plate is completely retracted and separated from the sealing surface of the valve body, continue to turn the handwheel to rotate the cock and the sealing sliding plate by 90°, and the valve is in the open position.
The elastic sealing ring is molded into the groove of the sliding plate. As the sealing sliding plate moves to the inlet and outlet of the valve, the sealing circle is gradually pressed into the groove. The mechanically processed sliding plate surface and the inner cavity of the valve form two parts. The grade gold-to-metal seal prevents the elastic sealing circle from being continuously pressed, and has a fire-proof function.
Image result for double block and bleed ball valve Testing for double block and bleed quality Valves requires the pressure-testing of each seat, with leakage measured through the Valve body bleed as a means of substantiating the independent leak tightness of both the upstream and downstream seats of the Valve.
These valves are available bi-directional in metal seated and soft seated style, in bubble tight shut off. Sometimes called twin valves, DB&B valves are available in Plug and Trunnion Ball type up to 600mm NB in ANSI 150 to 2500 class.
The double block and bleed system requires the use of two valves and a spool piece. A bleed valve is used to drain the spool and verify seal integrity.