This week, Plast-O-Matic Valves, Inc. (Chem Show, New York; Booth 1018) debuts an all-thermoplastic, air-operated pinch valve with a newly designed sleeve element. With an open tubular-sleeve element to control flow, the Series HSA pinch valves provide an open flow path to eliminate dead spots.
They are suitable for flow with particulate matter, as the elastomer sleeve will seal around solids that would typically prevent other valve types from closing.
Molded from EPDMh2 (a new ethylene-propylene-diene monomer), the sleeve element features a design with variable thicknesses and a tapered shape. The high elasticity, durability and longevity of the elastomer combined with the sleeve design allow the pinch element to achieve over 1,000,000 cycles under test conditions. The Series HSA has 0.5-in. true-union connections offered in threaded or socket styles and a 1/8-in. NPT connection for delivering compressed air. Valve operation requires a three-way air solenoid and a 45-psi over-line pressure for full closure. Valve body material is available in Geon PVC, Corzan CPVC, Natural Polypro or Kynar PVDF.