Drain valve (DV)

The Drain Valve is designed to discharge fluid from the tubing or drill pipe string into the annulus prior to pulling the string from the wellbore. Design features and operating principle: The valve consists of a steel cylindrical body with connections at both ends for integration into tubing or drill pipe strings. Internally, it features a knock-out screw and a perforated baffle. The baffle is secured inside the body by threaded engagement. A knock-out screw is installed inside the valve body. The drain valve is activated after the knock-out screw is mechanically sheared. At the end of operations, a drop bar is released into the tubing string, shearing the knock-out screw installed in the valve body and thereby opening the flow ports through which reservoir fluid drains into the annulus. The drain valve is designed for multiple use.