Should an emergency occur during a wireline operation, time may not permit the removal of the wireline tool string. Our extensively tested actuator supplies the gate valve with a closing force designed to cut the wireline and shut in the well.
The AWC wireline-cutting actuator is a hydraulically operated concentric design that adapts to a reverse-acting gate valve. The actuator/gate valve combination can cut 7/32-in. OD braided wireline with only the actuator closing spring force (zero valve body pressure).
When positioned as the upper master safety valve, the assembly is often the primary safety device during wireline operations. The assembly also enhances conventional surface safety protection during routine production.
During operation, hydraulic control pressure enters the cylinder of the hydraulic actuator. The extended stem travels downward until it is practically flush with the top of the cylinder, indicating the valve is open. The piston shoulders against the packing retainer and stops further downward force. The gate valve is fully open. The actuator is designed to maintain the valve (reverse-acting) in the open position with hydraulic pressure on top of the piston.
Loss of hydraulic pressure allows pressure in the valve body to move the stem and gate into the closed position.
The extended stem indicates the valve is closed. The met¬al-to-metal seat between the actuator bonnet and lower stem serves as a secondary seal when high temperatures have melted or distorted lower stem packing. Upstream valve body pressure helps to hold the gate in the closed position. The spring allows the gate to close with less than 100 psi in the valve body.
- 8,000-lb closing force as standard offering – Coil compression spring assembly designed to cut wireline, even with 100 psi or less in valve body. The closing force rises in proportion with increases in valve body pressure. Higher closing forces are available on special order.
- Fast closure – Possible with the lower actuator ratio
- Compact design – Outer cylinder protects bonnet and studs against high temperature and impact damage due to flush mounting of actuator to valve body. The short profile saves space and keeps service clearance to a minimum.
- Easy to maintain – Can be redressed by one person without special tools or external pressure sources. The actuator design allows for safe maintenance. Once the stem is completely unscrewed, the spring should be relaxed. A thrust bearing reduces turning effort on the torque applied to stem. The upper stem packing can be changed without disturbing the rest of the actuator. The lower stem packing is accessible without removing the bonnet.