A frangible ceramic disc is used in isolation subs to keep debris and heavy mud from setting on a top of a mechanical TCP firing head. Circulating ports located directly above the disc allow such solids to exit the tubing without becoming an obstruction to the firing mechanism. Clean light fluid is held between the disc and the firing head to ensure the drop bar impacts the firing pin with the required velocity to fire.
Design features and application:
- Isolates the firing head from debris or mud;
- Seals a clean fluid column on top of the firing head;
- Allows safe fluid circulation to make a pressure drawdown;
- Available in standard EUE thread.