User's View Of Sealless Pumps - Their Economics, Reliability, And The Environment

Tutorialpg. 127Numerous surveys have shown that the shaft seal is the dominate root cause of failure for the chemical process pump. These component failures are attributed with the lion’s share of the pump maintenance cost. Moreover, even a functioning seal cannot be classified as a zero emission point within a chemical plant; the cost of these emissions will continue to rise with time. Business competition and societal pressure demand that maintenance costs be reduced and chemical emissions to the environment be eliminated. The progress made by one chemical manufacturing company in their meeting these demands, while also satisfying the additional business objectives of safety, reliability, and profitability is reviewed. The mechanical features and hydraulic characteristics of various types of sealless pumps are described. Centrifugal pumps utilizing canned design features and magnetic drive technology are included. Guidelines for the economic justification of sealless pumps vis-à-vis sealed pumps are outlined in a simple life cycle cost model. Sealless pumps are not the panacea. As with most types of machinery, they are plagued by design limitations and/or faults. A cooperative program between sealless pump users, manufacturers, university laboratories and industrial component manufacturers aimed at delivering a reliable zero emission pump is briefly descried