John Crane Inflatable Seal Reduces Downtime and Prevents Product Loss

"Generally, when packing or primary seals on pumps and agitators in large volume tank services fail, the vessel's contents have to be quickly pumped elsewhere, otherwise a lot of product is lost," said Tom Evans, marketing manager of pulp and paper products for John Crane. "The Type 73 inflatable backup seal is an inexpensive solution that allows millions of gallons of product to remain in place while primary seal maintenance is performed."

The Type 73 inflatable seal uses a simple design with minimal parts. The key element is a heavy-duty "boot" developed by John Crane that inflates quickly with air, nitrogen, water or other inflation medium to hold the process fluids in place.

"The inflatable seal can be inflated and deflated through dozens of cycles," Evans added. "Since it is activated only while the equipment's shaft is not rotating, there will be virtually no wearing of the inflatable boot, guaranteeing years of service life. Some John Crane inflatable seals have provided more than ten years of uninterrupted service, and are still going strong."

Type 73 seals can provide backup seal protection when used with a wide range of primary seals and packings. They are ideally combined with the John Crane Type 37 series of split seals, which includes the Type 3710, 37FS and 37FSB seals.

"The Type 37 series are fully split seals, meaning installation, replacement and repair can be done without dismantling the equipment," Evans said. "And when combined with the Type 73 inflatable backup seal, there is no need to drain the entire system first, because the process fluid is contained."

The Type 3710 is a cartridge split seal, and is simple to assemble and install. Various seal face and elastomer combinations are available to fit a majority of service requirements.

The Type 37FS and 37FSB split seals are recommended for use on heavy-duty, typically packed equipment that previously could not accommodate mechanical seals because of severe vibration and difficulty in disassembly. Both seals are designed to operate in harsh conditions, and can handle severe shaft runout and vibration problems. The Type 37FSB can accommodate unusually high pressures.

According to Evans, all three John Crane split seals are outside-mounted, and repairable on-site, further reducing downtime.

A member of the Smiths Group plc, John Crane is the world's leading supplier of sealing systems and associated products, including mechanical seals, mechanical packing and sealing support systems as well as power transmission couplings and centralized lubrication systems. With more than 9,000 employees and facilities in 47 countries, the company serves customers in process, automotive and industrial markets.

For more information about the Type 73 inflatable seal and Type 3710, 37FS and 37FSB split seals, contact: Tom Evans, John Crane, 6400 West Oakton Street, Morton Grove, IL 60053; (847) 967-3875.