Valve stem seals are a typical example of dynamic seals.
The main factors to consider in sealing packing are the choice of material, the finish of the contact surfaces where sealing is generated, and their proper sizing.
Specifically, the choice of material will be a function of temperature, pressure, and the nature and concentration of the process fluid or gas.
A case of particular interest is sealing to the external environment, which should be considered not only in order to avoid the emission of harmful substances, but also as an opportunity to reduce maintenance work.
The graphite packing is researched and designed in such a way as to ensure, during translatory or rotational movement of the stems, compliance with international regulations known as “Fugitive Emissions Control,” thus reducing environmental impact.
CMD has extensive knowledge on the subject, the result of the experience of its technical staff, the countless tests performed in its laboratory, and its activities as a consultant to various users.