The heart of the air-operated double-diaphragm (AODD) pump is its diaphragms. They must be flexible enough to handle millions of pumping cycles without failing and be compatible with any number of different liquids or particulate-laden slurries. When used in hygienic-manufacturing operations, such as food/beverage, personal care or pharmaceutical, the diaphragm has another responsibility: it must be able to be cleaned easily, effectively and reliably in order to help ensure that no product contamination occurs.
Meeting that last requirement is often easier said than done. Most traditional diaphragm designs incorporate an outer metallic plate that creates areas where the pumped product can be trapped between the plate and the diaphragm, which requires that the pump be cleaned manually. This is both time-consuming and costly, and creates the possibility that some product may remain in the crevices between the metallic plate, outer piston and diaphragm, which can lead to product contamination in future production runs.
To help eliminate these cleaning and contamination concerns, Wilden® has developed the Full-Stroke Integral Piston Diaphragm (FSIPD) and designed it for use on its Saniflo™ FDA and Hygienic™ Series AODD Pumps. The FSIPD is constructed of food-grade Wil-Flex™ (Santoprene™) and its design integrates the shaft connection into the flexing material. The result is a unique and innovative diaphragm that features an unbroken fluid-contact surface, a large central hub for maximum displacement and longer rubber/TPE shaft that enables it to maintain the same stroke length as traditional diaphragms. This long-stroke configuration enables the pump to achieve three times the dry vacuum when compared to CIP-capable diaphragms that are constructed of PTFE.
The full-stroke design also increases product displacement per stroke, which translates into improved suction lift, greater flow rates and higher efficiencies than those offered by pumps that rely on reduced-stroke diaphragms. The design of the FSIPD also results in a 20% to 30% reduction in water and chemical usage when cleaning.
This “extreme” hygienic diaphragm is now being used in applications ranging from poultry processing with strict guidelines for sanitation, to the production and handling of a variety of sauces found on our kitchen tables, to the handling of some of the personal-care industry’s most shear-sensitive premium facial creams. All with the same objectives at play: ensuring that the purest product quality is maintained while improving production yields with optimized operational costs.
With the recent introduction of the 3” pump size, the FSIPD diaphragms are now available on Wilden’s 1”, 1.5”, 2” and 3” Hygienic Series pumps, as well as its complete line of High-Pressure Series AODD Pumps, including the H800 (2”) Advanced™ Series and H1500 (3”) Saniflo models.