Ball-throw internal pressure operated test tools, catalog page 37
Normally Closed Valve
Circulating valve opened by dropping a ball — used for circulation after testing
Description
The normally closed valve is a circulating valve whose circulating port is opened by dropping a steel ball and applying tubing pressure. It is usually used as a circulating valve after testing.
Features
- During downhole operation, the shear pin keeps the circulating port closed
- To operate, a steel ball is dropped into the tubing from the wellhead and fluid is pumped continuously by a pump truck at a set rate and pressure to open the port; the ball and sleeve then fall into the lower adapter
- Once open, the circulating port cannot be closed again
