Plastic Radiator Components
Don't Lose Their Steam

Giacomini S.p.A., an Italian producer of components for thermohydraulic applications, is manufacturing two of its newest products from a single material, rather than the three used in earlier models. The material is CARILON polymer, an aliphatic polyketone made by Shell Chemicals, Houston, TX.

The R470 thermostatic head made by Giacomini allows the temperature of a heating radiator to be adjusted by means of a fluid-cell sensor fitted inside the radiator. The temperature of each room can then be adjusted locally, conserving energy in the home or office. The three elements of the R470, all molded from CARILON, include a handwheel, base and locknut. The handwheel design is cage-like for better grip, rather than a solid structure, which would be dust- and dirt-retaining. The CARILON polymer's high molding definition characteristics lent themselves to the complex shape, making molding easy. Since the thermostatic head is fastened to a metallic element, it must guarantee high mechanical strength at temperatures up to 90°C. Plus, the unit is subject to frequent opening and closing operations, which must be carried out without deformation, loosening or breakage.

Giacomini also used CARILON for the handwheel in the R66A manual radiator air valve, which has a valve body made of brass. The CARILON handwheel has low thermal conductivity and good dimensional stability through the radiator's range of working temperatures. Previous handwheels, made from polyacetal resins, tended to break around the threads during high stress conditions.

The Italian UNI215/1 standard imposes very strict requirements for thermostatic valves under a static pressure of 100kPa. After 20 minutes, the time needed to reach thermal stability, a force of 25 kg is applied for 30 seconds. The product must exhibit no damage, such as permanent deformation, breaks or cracks. Giacomini found CARILON polymer fulfilled all their needs, plus provided improved color matching in production.

-- RM

For more information, contact Shell Chemical Co., PO Box 2463, Houston, TX 77252-2463. 888-CARILON. Circle 585.