AST S.p.A. products

Main features: AST produces a complete series of control valves with electric or pneumatic spring-diaphragm actuators. Materials: carbon steel, alloy steel, hastelloy, monel and other materials upon request. Accessories: handwheels (side and top mounted), stem bellows for bubble tight sealing, pneumatic, electropneumatic or digital positioners, filters, boosters, lockup valve etc.

Main features: Specially designed for critical service applications, where higher performances than conventional contoured plug, screwed seat valves are required, CV-8450 (straight way body) & CV-8750 (angle body) series valves feature a cage based robust, simple and reliable design with a wide range of anti-noise, anti-cavitation and velocity-controlling trims for heavy-duty applications. All valves have quick change design with seat locked by the drilled cage also guiding the plug for the whole stroke, realizing flow control and allowing plug balancing to reduce actuating forces. The trim design, with internal thermal differential compensation system, allows to extend working temperatures from -55 °C (-196 °C for the cryogenic series) up to 566 °C. A large number of plug balancing solutions allows to reach highest sealing classes in the whole range of operating temperature with reduced actuating forces.

Valve Series CV-870U & CV-870S were specifically developed to satisfy the high reliability and the best performance required in urea and melamine plants; experience gained in the field, fluid-dynamic feature optimization and the use of specific materials allow the obtaining of high resistance to erosion and to corrosion in presence of particularly aggressive process fluids even at high pressure and temperature values. Our valve design also takes into consideration easy assembly and disassembly of internal parts to facilitate maintenance operations. Upon request, valves can be provided with electrically traced jackets or jackets with diathermic fluids to heat valve body at the required temperature. Flushing ports are often provided to clean valve trim, in order to avoid crystallization and deposit, granting superior reliability. The actuator and instrumentation provided with the valve are carefully selected and calibrated to ensure the best control performance.