Diaphragm valves are the most commonly used valves in sterile processes or pharmaceutical applications within the pharmaceutical, food and biotechnology industry. Strict validation processes, manufacturer’s guidelines and hygiene regulations must be adhered to, especially in the pharmaceutical sector. Reliable performance of the separating diaphragm is key to ensuring this goal is achieved. Bürkert Fluid Control Systems has therefore optimised the diaphragm contact surfaces in the valve seat and at the so-called pressure piece of its diaphragm valves.
The improved geometries ensure the diaphragm load is better distributed, thereby increasing the diaphragm life time by up to 50%. This has been confirmed through tests carried out by the independent test house ‘Bioprocess Institute’, which installed, tested and positively evaluated the diaphragms of Bürkert diaphragm valves in accordance with ASME BPE Appendix J Exposure Conditions (SIP and CIP). The extended life time helps to cut operating and maintenance costs and to enhance process reliability. Thanks to a bayonet catch, thread or button fastener, the actual diaphragms are quick and easy to replace, e.g. when changing products. The pressure piece is automatically prevented from falling out, which provides added safety during day-to-day installation operations and saves time.
Enhanced process reliability, reduced energy consumption
In addition to the reworked contact surfaces, axial sealing lips have been incorporated into the diaphragm valves to minimise wear during continuous operation (image 2). This enables better grouting and reduced spring force with an unchanged diaphragm surface. Hygiene and process reliability are also improved thanks to the effective barrier to external media. Besides EPDM and PTFE, a new diaphragm made from GYLON (restructured PTFE with fillers) is now also available for particularly challenging requirements. The material is characterised by its low permeation and high resistance to various chemicals. Moreover, it is considerably less prone to deformation than pure PTFE when subjected to higher mechanical and thermal loads or temperature fluctuations, and does not demonstrate a ‘cold flow’ tendency. The durable, low-maintenance diaphragm valves can be assembled from a wide range of bodies, diaphragms and actuators to suit every application. In addition to forged and cast bodies, the hydroformed Tube Valve Body provides the Bürkert portfolio with an innovative body whose lightweight design saves energy and time during the warm-up and cool-down process respectively, and thus has the added benefit of saving costs.
