The Direct Pressure Firing Head is specifically designed for well conditions where dropping a detonating bar is impractical or when a backpressure-activated firing mechanism is required.

This firing head is engineered to activate at a predetermined pressure using precision shear pins. The firing piston is secured within the retainer sleeve by these shear pins, with the number of pins determined by the well conditions and the desired safety margin.

Activation occurs hydraulically through the combined effect of hydrostatic pressure and applied pressure, ensuring operation within ±15% of the calculated values. Once the precision shear pins fail at the designated pressure, the firing piston propels the firing pin into the percussion initiator, initiating detonation of the perforating gun assembly.