Sealing Technology

The gasketed plate heat excheangers of the SIGMA series can be equiped with different types of gaskets.
According to the field of application it's advisable to use either elastomeric gaskets made of NBR, EPDM, Viton or other special materials or fall back to use asbestos free hard gaskets as well.
In principle, all gasket solutions show a double sealing between both product flows.
The space between the both gaskets is opend to atmosphere by a leakage groove.
Unless the leakage groove is not blocked by dirt or something else, there's no possibility to mix the fluids when a gasket breakdown shoukd happen.
The gasket fixation on the SIGMA heat exchanger plates can be done in case of Elastomer- and SIGMACOAT-gaskets either mechanically using our SIGMAFIX fastening systems or glued - as in the case of using hardgaskets.

Our patented SIGMAFIXadhesive-free gasket fastening system guarantees fast, easy and economical gasket change through laterally built in fixing clips. This patent ensures a high resistance against front-face-sticking and minimises the risk of gasket being stuck to the following plate.
Through the large area of contact between the mounting clips and the heat exchange plate a better fixure and a fail-save seal is created. The advantage of the high elasticity of the SIGMAFIX can also be seen under variable service conditions.
The condition of the seal can be inspected visually on site without opening the heat exchange core.
The SIGMAFIT system is available for all of oour standard plate heat exchanger in a variety of rubber like gasket material. Its maximum operating pressure is up to 25 bar.

The SIGMACOAT (NBR or EPDM) elastomer gasket has a diffusion barrier shell out of the PTFE. This special coating ensures resistance against all aggressive mediums at processing temperatures of up to 160°C.
Another advantage lies in the prolonged lifetime of the gasket, which guarantees a sure and reliable productions process.
Also available in the glueless SIGMAFIX gasket system, this combination of SIGMAFiX coating with elatomeric materials gives a high economic advantage to our customers.