Hot isostatic pressing is in vogue as a forming process for critical components, but a parallel technique— cold isostatic pressing — is available, too; and, the builder of many HIP systems has delivered what may be the largest CIP system in the world to a Pennsylvania operation.
Mersen USA in Saint Marys, PA, formerly a Carbone Lorraine operation, is the largest producer of specialty graphite in North America. Its iso-molded graphite products are used in a range of refractory applications, where they deliver high density, thermal conductivity, low thermal expansion, and high thermal shock-resistance.
Isotropic graphite, as the material is known, is produced by forming and densifying powdered material using liquid or gas under extremely high pressure. Isostatic pressing works by imparting pressure equally on an object from all directions — unlike mechanical force, which focuses pressure on a workpiece from one or two sides. The method eliminates internal porosity without changing the shape of the object.
The construction of the new press was an 18-month project for Avure Technologies Inc. (www.avure.com), which builds hot and cold isostatic press systems. The new machine’s dimensions are 31.3×23.6 ft, and it weighs a total of 550 tons. It is powered by two 300-hp pumps and operates at pressures in excess of 20,000 psi, with operating cycles averaging one hour.
Mersen’s new machine has a working cavity of more than 500 ft3, meaning it’s able to produce graphite products weighing more than 14,000 lb, the largest isostatic graphite parts in the world, it said.
Avure Technologies will customize CIP systems according to manufacturers’ size and pressure requirements, with pressure vessel diameters from 2 to 117 in. (51 mm to 3 m), and pressures up to (100,000 psi.) Vessels are built to ASME Section VIII, Div. 3 standards, and can be certified in accordance with CE and the PED, the European Pressure Equipment Directive, and other international pressure vessel regulations.