Nutberry gas springs / thermodynamic elements have an unparalleled reputation for reliability and are the most technically advanced product available for many steel plants throughout the World.

Nutberry have been manufacturing and designing gas springs for Flogates, Vesuvius, Knoellinger, Magnesita, Deguisa and other users of slide gate mechanisms since 1976. We very much like to work with mechanism manufacturers to enable us to design a spring together, that may provide an alternative and up-to date solution to high temperature problems. We would provide a design to meet your mechanism requirements and once approved, supply a set free of charge for you to test and validate.

Nutberry uses advanced technology with CNC machining and automated computer controlled bellows forming machines. There are many advantages to using Nutberry gas springs over more traditional methods of coil or disc springs, which can relax at elevated temperatures.

The superior quality is such that although they are designed and guaranteed to operate at temperatures up to 500’C, in many cases they have been used at temperatures in excess of this and continue to be used with excellent results. All Nutberry gas springs are leak tested with a mass spectrometer ensuring that no leaks are present.

Nutberry have also developed Hybrid Gas Springs and Balanced Gas Springs that produce a flatter force/temperature gradient, with both designs having a back up force for added safety.

Nutberry design gas springs to suit customer requirements.



GUARANTEED RELIABILITYNutberry Gas Springs are the only gas springs with a GUARANTEE
COST EFFECTIVENutberry Gas Springs are guaranteed for a minimum of 500 cycles at 500 degrees Celsius.
NO COOLING MEDIUM REQUIREDOnce the operating temperatures have been established and the correct Nutberry Gas Springs installed, it is possible to operate the gate valve without the introduction of a cooling medium. Thus further reducing operating costs.
HIGHER SAFE OPERATING TEMPERATUREGas Springs operate at temperatures above those possible with coiled springs, keeping gate valve mechanisms safer should there be a temporary shortage of cooling medium. Latest designs incorporate a fail safe mode.
Users of Nutberry Gas Springs have achieved a higher plate life by controlling the force applied to them and giving them a more evenly distributed force.
Being able to operate without a cooling medium assists the production of clean steel by providing an oxygen and nitrogen free atmosphere in the area of the refractory plate.




FT Thermodynamic Elements

FT Thermodynamic Elements


Thermodynamic Elements in Flocon Mechanism at Elevated Temperatures

Nutberry Balanced Spring

The balanced spring has been designed to operate at temperatures up to 600C and provide a narrow flat force/temperature curve tolerance.

This is achieved by a mechanism to stabilize the increased pressure/force at operating temperatures and therefore generate a relatively constant force throughout the temperature range.balanced-spring

Balance Spring – two chamber gas spring for balanced for Fail Safe Design

The Balance Spring works by the introduction of a second chamber whereby an opposing force is generated at elevated temperatures balancing the force generated by the main chamber. The second chamber also provides a failsafe mechanism as when the first bellows fails the second bellows maintains the gas within ensuring force is still applied by the spring.

Nutberry Hybrid Spring

Due to the possible excess force applied by the pure gas spring for some slide gate mechanisms Nutberry have developed a hybrid spring. One that incorporates both gas and a mechanical spring deflection, providing a combined total load.


Hybrid Spring with internal inconel compression spring.

By reducing the initial amount of pressure injected into the gas spring at ambient the force/temperature gradient would be considerably flatter. To make up the remaining force required, an internal spring is located inside the ram of the gas spring (please see drawing below). As the temperature increases the gas pressure inside the hybrid unit is less than a standard gas spring where the total force is made up of gas alone. Depending on the ratio between gas and spring the force/temperature curve can be manipulated to provide the desired shape.

By having a secondary spring inside the unit also addresses the problem of immediate and complete failure. Once the gas has been expelled (after bellows failure) the force from the spring remains, providing a limited amount of load to the plates.

Benefits of Balanced Spring

No relaxing/creep of Inconel spring at temperatures above 500C.
No cooling required.
Fail Safe - once outer bellows fails inside bellows maintains force at operational temperatures.
Force can be controlled through temperature range by adjusting opposing force in second chamber.
Lower cost than Inconel Compression Spring.


If you require further information or wish to discuss your specific requirements, please contact us: Telephone Number: 0044(0)1323 442070.