To respond to the significant expansion of the industrial valve market, Carrara has organized the production of its PLANIGRAPH graphite rings according to the most modern requirements. The company has scaled its manufacturing systems to flexibly meet customer needs and, thanks to a significant equipment fleet and a modern, precise production schedule, Carrara can manage batch sizes ranging from a few units to thousands, always using Expanded Mineral Graphite of various purity grades, yet always of high quality.
The molding department is capable of producing custom-made graphite sealing rings, with dimensions ranging from 10.0 to 2,300.0 mm, for various applications.
Expanded mineral graphite is characterized by a high carbon content, typically in the range 98.00% ≤ C ≤ 99.85%. To properly qualify the product, values of Sulfur (S), Fluorine (F), and Chlorine (Cl)—halogens regulated by standards—must also be indicated.
Graphite can also be protected with passive corrosion inhibitors and oxidation inhibitors, depending on its grade. Expansion is the process by which graphite grains exfoliate into flakes. These graphite flakes are cold-rolled without the use of binders to create expanded mineral graphite sheets, which are then used in a wide variety of sealing systems.
The main reference standards are ASTM F2168 and MSS SP-120, although each oil and gas producer may have its own proprietary specifications.
