The Elbi Accumulator Pressure Vessel with bladder is a device that will provide system water at a pre-set, sustained pressure. The function of an accumulator vessel is to sustain system pressure by feeding additional water into the system at the required pressure. This process will limit the number of times the pump needs to start (pump hunting) in order that system pressure remains at the optimum level.
The process is achieved by the addition of a pre-charged nitrogen cushion at higher than atmospheric pressure within the vessel shell. This pre-charged cushion is stored between the water bladder and the inner surface of the tank.
Unlike standard air-cushioned accumulators without bladder, the accumulators with bladders feature the following advantages:
• energy saving: reduced number of pump start-ups;
• installation cost reduction: lack of water contact means that air is no longer dispersed into the water and therefore, there is no further need to supply a compressor to restore the cushion;
• maintenance costs reduction: only the tank pre-charge pressure has to be checked. Additionally the bladder can be replaced, disassembled and reassembled easily in a very short time;
• stored volume reduction: space saving;
• water contamination risk is reduced: the bladder also serves as protection against any substance suspended in the air, such as: oil, smoke, bacteria, smells, dust, etc. that may alter the quality of water. Bladders are certified for alimentary use;
• long-lasting tank: the fact that the bladder prevents water from being in direct contact with the inner surface of the tank significantly reduces corrosion;
• dual purpose: this type of tank will also cushion water hammer.