Powell Fabrication & Manufacturing, Inc.

Low Torque Shutdown Systems & Automatic Valve Operators

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UniPro™ LT (Low Torque) Pneumatic Emergency Valve Closure System

The only low-torque emergency shutdown technology designed for 20-ton bullet tanks to 90-ton railcars, this patent-pending system prevents reportable releases of pressurized hazardous gases at the source. Plus, the UniPro™ LT system is specifically designed for "low-torque" valves to prevent damage to the valve seat. Improve your Risk Management Planning (RMP) scenarios with a pneumatic-powered system that not only promises easy installation and low maintenance, but also superior performance and reliability.

UniPro LT

The UniPro™ Pneumatic Valve Closure System is engineered to be the most versatile, efficient, and reliable unit on the market. The system includes the actuator, control panel, air control unit, and air supply hose. More...


Designed to close a variety of low-torque, plug-type angle valves on railcars and tank trucks. These soft-seat valves are often marked with warnings to operate by hand only. Not intended for use on any high-torque valves that require tools to close and seat completely.


Ideal for applications where air or nitrogen are readily available. Requires 90 psig to operate. Fail-closed design operates even if AC power or air pressure is lost.


Robust motor requires no lubrication, and is completely encased by a steel cover for protection and years of reliable service.

**Designed in accordance with The Chlorine Institute’s guidelines for valve closure systems.


Automatically responds to any alarm input, closing valves with 120 lb-ft of torque in less than 10 seconds.


Designed to close a variety of plug-type angle valves on railcars and tank trucks with dome sizes between 24 and 42 inches in diameter. For use on containers of chlorine*, sulfur dioxide, anhydrous ammonia, liquid hydrogen chloride, and other pressurized hazardous gases.


UniPro LT Dimensions Various valve adapters are available depending on your particular application (torque requirements, valve handle configurations, material hazards, spark resistance), and all easily attach and detach with a single hitch pin. With the torque-limiting adapters, there is no need to reduce the air pressure to potentially unreliable levels in order to prevent damaging the soft seat of low-torque valves.


Easily mounts to the dome wall in seconds, without tools. Can be quickly removed from the valve handle without detaching from the dome wall to facilitate manual valve operation. Weighs just 28 pounds.

Designed for Durability

The actuator is constructed of aircraft-quality aluminum and high-grade carbon and stainless steels for maximum service life. The housing is sealed to prevent intrusion from dirt and water in outdoor applications, while a two-step polyurethane coating provides corrosion protection.

The UniPro™ is designed to stand alone as a complete system, or to integrate and interface with existing unloading components. The included air supply hose has a safety swing coupling to ensure a secure connection between actuator and gas supply.

Maximum Control

UniPro Control Panel The UniPro™ Control Panel automatically activates the actuator to close the valve in the event of a gas leak, car movement, fire alarm, seismic event, security breach, process shutdown, or other monitored condition. You can also manually activate the system by depressing the emergency stop button on the panel.



Air Control Unit

UniPro Air Control Unit The air control unit supplies the proper amount of clean pressurized air to the system. Available in two sizes to operate up to six UniPro™ actuators simultaneously.

The UniPro™ Pneumatic Valve Closure System is engineered to be the most versatile, efficient, and reliable unit on the market. The system includes the actuator, control panel, air control unit, and air supply hose.


The UniPro™ name represents a whole family of pneumatic actuators for railcar and tanker applications, including the standard, reversible and low-torque models, all designed for plug-type valves, plus a quarter-turn model specifically designed for ball-type valves. The control panel, air control unit, and all optional system components work with any of our pneumatic actuators.

UL - CUL Approved

Powell Valve Closure System control panels (UniPro™, MaxPro™ RA & E-Pro®) are listed by Underwriters Laboratory to UL 508A for Enclosed Industrial Control Panels. Panels are listed by Underwriters Laboratory bearing the UL & CUL mark for use in the United States and Canada markets. In applications where a CSA listed control panel in Canada is required, please contact Powell for further information.