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GIS Valve

The GIS Valve is a hydraulic pilot-operated high-pressure and temperature safety steam valve system developed by Greno Industries in 1978 for the United States Navy. It has been used on over 400 US Navy ships to enhance performance and reliability. Over a period of eight years, every non-nuclear surface ship was retrofitted with Greno’s GIS Valve. To this day, the GIS Valve is still in use and being serviced.

About the GIS Valve


The GIS hydraulic pilot-operated power control valve is designed for safety, durability and ease of maintenance. Its unique design provides operations reliability for systems ranging in pressure up to 3000 psi, at temperatures up 1100 degrees Fahrenheit. Design advantages include:

  • High accuracy and repeatability. Because of remote operation, the pilot valve is not affected by extremes of temperature. Plus our design results in more accurately balanced boiler operations at peak loads.
  • Increased efficiency. The precision of this valve allows operation closer to set point than conventional valves, and eliminates unnecessary opening of power control valves.
  • Increased safety and ease of adjustment. Because adjusters are located on the remote unit, operators are not exposed to hazardous conditions when adjustments must be made. In the event of power outages, the supply valve safely operates without an external power supply.
  • Simmering eliminated. Due to full valve lift, giving maximum flow at set pressure, there are no secondary lifts or closings.
  • Leak-free operation. Steam leakage from the pilot valve is eliminated by pressure-loading design.

Reduced maintenance. Modular design facilitates ease of maintenance and/or replacement.

Economic advantages of the GIS Valve

The superior design of the GIS valve system offers numerous economic advantages. With our design, existing power control systems can be reduced to a single system, trimming maintenance and supply costs. The GIS modular design also greatly reduces maintenance costs, while the elimination of steam leaks results in more efficient, economical operation. The GIS system offers a flexibility that allows us to custom-design a valve that works with your existing system, so you have the option of upgrading without a complete redesign.

GIS valves are built to last. Quality control of raw materials is meticulous; remote operation results in reduced wear on the system; hard surfacing alloys on disc and nozzle ensure durability. In addition, the pilot valve unit does not require exhaust piping or expansion joints, which eliminates piping strain and maximizes valve life.

Field servicing, installation, and on-site support operations are available for the GIS Valve. To learn more, click here.