Our Axelson™ AUP pnuematic actuator is designed to close a reverse-acting gate valve upon loss of pneumatic pressure. The actuator can be installed on secondary master valves, wing valves, flowline valves, header valves, pipeline system valves, and casing relief blowdown valves.
The piston area provides high operating ratios, and the design is suitable where low control-line pressure is required to open and hold the valve in the open position.
Maximum actuator working pressure is 375 psi. Actuators are available in various sizes for API gate valves from 1 13/16 to 48 in.
During operation of the pneumatic AUP piston actuator, pneumatic control pressure enters the cylinder above the piston. The extended stem travels downward, indicating the valve is open. The adjustable internal down-stop prevents further downward force. The gate valve is now fully open. The actuator is designed to maintain the valve (reverse-acting) in the open position with pneumatic pressure on top of the piston.
Loss of pneumatic 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 metal-to-metal up-stop between the Axelson actuator bonnet and lower stem serves as a secondary seal when high temperatures have melted or distorted lower stem packing.
The upstream valve body pressure helps to hold the gate in the closed position. The internal spring ensures the actuator will return if there is no valve body pressure. The extended stem indicates the valve is closed. The metal-to-metal seat between the actuator bonnet and lower stem serves as a secondary seal.
- Simple, field-proven Axelson design – Proven design features make it simple to service with standard tools.
- Easy disconnect – Actuator can be removed from the valve without the use of an external pressure source and with minimal tools.
- Visual open/close indication – Upper stem extension indicates gate position at a glance.
- Interchangeable with all other AU models, allowing conversion from hydraulic to pneumatic actuation and vice versa