OEM

Butterfly valve seals for triple offset valves offer optimum functionality and leak-tightness. Designed for critical applications, they are resistant to high temperatures and pressures, abrasive media and media prone to crystallization. The characteristic sandwich design of the gasket, with alternating combined foil layers of expanded pure graphite and intermediate layers of metal, results in ideal bonding of the material layers and ensures triple safety against leakage.

The graphite provides the necessary elasticity to press the metal elements against the seat. Reliable seat tightness is achieved by the metal layers joining seamlessly to the body. The specially machined inner contour of the gasket has a crucial impact on the tightness achieved by the valve and can be produced with high-quality surface finishes to meet customer specifications. A wide range of stainless steels and special alloys are available as metallic materials, which can be combined with proven soft materials such as graphite, PTFE and mica.

For highly sensitive applications, such as use in oxygen lines, graphite-based butterfly valve seals can be manufactured with the innovative LE-SAFE technology without the use of adhesives. In these technically high-performing seals, the metallic carriers are bonded to the pure graphite components without the use of adhesives. In critical applications, adhesive can have a negative impact on the performance of shut-off valves. In oxygen-carrying equipment and components, it carries the risk of unexpected fires. As the adhesive is superfluous once the seal is fixed in place, the LE-SAFE butterfly valve seal offers improved product characteristics with clear advantages: reliable mechanical properties [strength] and leak-tightness [leak class], sealing characteristics that match those of traditional seals with adhesive. As a result, risks are minimized, leakage paths eliminated, erosion and working temperature resistance optimized and a long service life of the entire system ensured.

All dimensions up to outer diameter ≤650 mm possible, as well as parts tailored to customer requirements. Low leakage rate, easy to adapt to different valves and housings, suitable for extreme operating conditions.

PTFE high-performance plastics are our strength. They are used in critical applications – where reliability and safety take priority, and outstanding material properties are without alternative. We produce PTFE semi-finished products [press-sintered parts or extrudates] and PTFE molded parts as well as composite parts made of PFA and metal with precision and technical know-how. We are also experienced in processing other fluorinated polymers such as PVDF and PCTFE and engineering plastics such as PE-UHMW, PEEK and POM.

To serve customer needs fast and flexibly, we stock nearly 20 custom compounds in addition to the pure, virgin PTFE and the more diffusion-resistant Dyneon TFM®. Compounding allows us to meet individual requirements, adapt and improve upon the already very advantageous properties of PTFE. For this purpose, organic or inorganic substances such as graphite, glass fiber or quartz are added to the material.

The material properties of PTFE include:

• Heat resistance from -268 to +260°C

• Almost universal chemical resistance, even to aggressive media

• Low coefficient of friction, high elongation at break and reverse bending capacity

• No material adhesion due to low surface tension

• Physiologically harmless even in continuous operation up to 260°C

• Insensitivity to weathering, and high UV stability