Lime is used in many chemical plants, where it is added to the influent to maintain an optimum pH level. Lime is normally stored as a dry powder, and mixed with water or additional chemicals to create a lime slurry that can be pumped through pipes and added to the waste stream as needed. Lime slurry is slightly abrasive, but can be quite corrosive depending upon the other chemicals involved.
Lime also has a tendency to build up as scale inside pipes and valves. This scaling can severely inhibit the operation of traditional quarter-turn valves and restrict flow. Traditional valves also suffer the problem of dewatering, which happens at the point where pressure is shut off. The upstream pressure in the line ahead of the valve will force liquid out of the lime, leaving a dry plug behind. This plug is hard enough to block to opening of a quarter turn valve, resulting in the use of cheater bars to open valves. Broken stems are a common result.
Because the shape of the elastomer sleeve changes as it opens and closes, it breaks up solidified lime and allowing it to pass. There are also no cavities or dead spaces in which lime can accumulate.
Control Pinch Valves (Maximum Durability with Precise Control)
Red Valve Control Pinch Valves offer maximum durability with precise control and virtually no maintenance. A heavy-duty, rugged pinch mechanism positions the sleeve, resulting in accurate flow control. Our Control Pinch Valves have no packing to maintain or seats to wear, no fugitive emissions and no need for expensive body alloys. Variable orifice and cone sleeves can be specified to further enhance control performance and match the exact CV level desired. True feedback positioning is accomplished through the direct linkage of the pneumatic positioner to the valve stem shaft, with no splitting of the positioner output. Red Valve Control Products are available with pneumatic, electropneumatic, or digital positioners to link up to all control systems.
Manual Pinch Valves (Engineered for Tough Slurries)
Red Valve’s Manually Actuated Pinch Valves are reliable, maintenance-free, cost-effective valves engineered for tough slurries, abrasives, and corrosive chemical applications. The 100% full port design eliminates any dead spots or crevices, seats or bearings where slurry can hang up and impair operation or even cause complete valve failure. Manual Pinch Valves feature bi-directional drop tight shutoff in a design that meets the same face-to-face dimensions as gate, plug, and ball valves up to 12″. Manual Pinch Valves employ Red Valve’s state-of-the-art elastomer technology to provide smooth venturi flow, centerline closure, and excellent throttling characteristics. A number of options are available, such as the Series 75B design for buried-service conditions. AWWA nuts, chainwheels, stem extensions, and bevel gear actuators are also available.
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