井筒隔绝阀属于投球关闭阀，一旦关闭后就形成了管内和管外的隔离，此时可以打压坐封所有的管外封隔器以及顶部悬挂封隔器。在压力滑套打开之前能够保证井筒 与储层处于隔离状态。

WELLBORE ISOLATION VALVE

Wellbore Isolation Valve is a kind of ball check valve. And once the valve is closed, the isolation is done between inside and outside of the string. Meanwhile, apply pressure and set all the external  casing packers and top suspension packer. And ensure wellbore and reservoir be isolated before the Pressure Actuated Frac Sleeve is open.

Note: Other specification products are available.