Non-lubricated metal seated  API599 plug valve were developed over 80 years ago to solve problems with existing valves in catalyst cracking service. As the valves preformed so well in this service it was also recommended for use in other hash applications in the chemical & petrochemical industry.As the valves preformed so well in this service it was also recommended for use in other hash applications in the chemical & petrochemical industry. To explain why the valve has been so successful we below stated the design features of the valve to provide more insides in its strengths. 

PRINCIPLE OF OPENING AND CLOSING OF THE   API599 plug valve

Opening of the valve:

• 1)turn the hand wheel to make the plug lifted and separated with the sealing surface;
• 2)then turn the handle lever by 90 degree to connect the channel of plug to the channel of valve body,so the plug valve is opened.

During the opening and closing of the valve, the plug is lifted and separated from the valve seat, so the operating torque is very small,very easy to open and close the valve. And the sealing surface is scratched proof during the opening or closing process. So the valve has longer life. The handwheel handle lifting type plug valve has a compact structure, small volume and low fluid resistance.