Designing a better mechanical seal

This month Larry Bachus, The Pump Guy from Nashville, wrote to, sounding off about mechanical seals, and why most people, when asked about pump problems on their plant, mention the seals (Link). Mechanical seals were first patented in 1903, around the time the Wright Brothers first flew: but Larry wants to know why we have not managed to improve the design as much as that of the aeroplane. He considers that “We need a seal for cavitating pumps. We need seals for deadheaded pumps and dry-running pumps. We need seals designed for pumps that are forced to operate on the extreme end of the performance curve for extended periods. We need a seal for starved pumps. We need mechanical seals designed to handle production upsets. These are the reasons that too many pumps suffer premature seal and bearing failure.”

Larry reckons that mechanical seals leak either at the seal faces, or through the secondary elastomer component, normally an o-ring. It would be great for the seal companies and pump companies to get together and jointly direct their brains and efforts toward the seal-face union, and the secondary elastomers, to sort this problem out! Larry is retired now, but still learning, and using his free time, in a slack economy, to improve his education. In recent weeks, he has attended a valve seminar, a short course on process piping, and a pump conference – not as the lecturer, but to learn. “Don’t ever let your education stop,” says Larry, while there are problems like mechanical seals to sort out.