Caustic applications in chemical plants can play havoc on the mechanical seals of rotating equipment. These applications can be difficult to seal because of the caustic chemical properties in both solution and dehydrated states. Caustic solutions form harmful crystals as the liquid evaporates and the concentration increases past the solubility point. As the solution becomes hotter or more concentrated (or both), it becomes more corrosive, further impacting mechanical seal reliability.
Each caustic application presents unique complications due to different concentrations, desired purity levels and pump design. As a result, seal manufacturers have developed seal designs and support systems to ensure that the seal will survive the harsh demands placed on them by the pump, the process and the operating conditions. Among these new seal designs is the upstream pumping (USP) technology.
Understanding these seal design options and arrangements for caustic applications, along with their benefits and shortcomings, will help chemical operations avoid costly mechanical failures, equipment damage, impacts to the environment and personnel exposure to hazardous materials.
Read the full article published in Chemical Engineering magazine.
Link: https://www.chemengonline.com/sealing-technology-for-caustic-service/?pagenum=1