Method of and apparatus for pressure buffering all leak paths of a lined plug valve
AssigneeXomox Corporation
InventorRussell G. Smith
Life of this patent
Estimating the term…
Abstract
External and internal leakage of line media from a plug valve is prevented by the continuous application of a buffering media at all potential leak paths at pressure greater than the pressure of the line media.
Claims17
The improvement which confines any leakage to externally applied pressurized buffering media rather than line media in a rotary plug valve of the type which includes a body portion having inlet and outlet ports, a plug rotatably mounted in the body and having a through-port defined therein for fluidly connecting the inlet and outlet ports to permit flow of line media through the valve, means for rotating the plug to selectively fluidly connect and isolate the inlet and outlet ports, upper and lower chambers defined in the body portion adjacent opposite ends of the plug, and means fluidly connecting the upper and lower chambers for establishing a condition of fluid equilibrium therein, the improvement comprising:
- means for introducing pressurized buffering media to said chambers;
- means for introducing pressurized buffering media into the through-port of the plug when the inlet and outlet ports of the valve body are fluidly isolated from each other by said plug so that when said inlet and outlet ports are in fluid communication via the through-port of the plug the pressurized buffering media in said through-port is exhausted into the line media;
- and
- means for connecting each of the aforesaid means to an external source of buffering media at a pressure above the pressure of the line media.
An improvement in a method of precluding both external and internal leakage of line media from a plug valve of the type which includes a valve body having inlet and outlet ports and a plug with a through-port defined therein for selectively fluidly connecting and isolating the inlet and outlet ports, a lower chamber in open communication with the lower end of the plug member, an upper chamber in open communication with the upper end of the plug and means fluidly interconnecting the upper and lower chambers, the improvement comprising:
- pressurizing a buffering media to a pressure greater than the pressure of the line media;
- continuously applying the pressurized buffering media to the valve at all of the potential leak paths of line media from which leakage of line media could occur but for the presence of the pressurized buffering media, whereby any leakage will be buffering media rather than line media by:
- introducing and continuously maintaining the pressurized buffering media in the said chambers thereby buffering them;
- introducing and continuously maintaining the pressurized buffering media in the through-port of the plug when the inlet and outlet ports of the valve body are fluidly isolated from each other by the plug thereby buffering the through-port of the plug;
- and
- exhausting the pressurized buffering media in the through-port of the plug into the line media when the inlet and outlet ports of the valve body are in fluid communication via the through-port of the plug.
Dependencies are inferred from the claim text.