Choosing the Right Split Cartridge Mechanical Seal

A variety of factors must be considered when you’re deciding which split mechanial seal to use. These choices fall into two categories: the component-style which also includes ‘semi-cartridge’ designs and the two-piece fully split cartridge mechanical seal design. Flexaseal’s Style 85 fully split cartridge mechanical seal has the clear advantage over component-style split seals in a variety of sealing scenarios.

For instance, the Style 85 is the clear-cut preference in the following pump arrangements:

  • The Style 85 two-piece split cartridge mechanical seal is engineered for pump shafts up to 11.00” – far exceeding the range of most component-style and semi-cartridge seal designs currently available.
  • Have a pump in an awkward location or with a lot of pump insulation? The Style 85 is simple and quick to install, eliminating the need to spend unnecessary time and energy with pump preparation.
  • The Style 85 fully contained two-piece design just make sense for double-ended pumps: no need to dismantle the entire pump if only one seal needs maintenance.
  • It is not necessary to remove the complete top assembly on most large vertical pumps to install a Flexaseal Style 85 split cartridge mechanical seal.

Here’s a side by side comparison of how component-style and semi-cartridge seal designs stack up to the Flexaseal Style 85 fully split cartridge mechanical seal.

Component Style Split Seal Style 85 Fully Split Cartridge Mechanical Seal
Seal components are immediately exposed to contamination once unpacked and handled. All delicate components are encased and protected in the cartridge halves.
If a component is lost or damaged, an entire new repair kit must be ordered. Since only the two halves are handled, no loose or delicate parts can be dislodged, lost, or damaged.
The responsibility for sealing success is on the operator to install all components in the correct order and with precise placement to avoid creating leak paths. The Style 85 is assembled and pressure tested at our facility before being sent to the field. This process ensures a high success rate on start up.
Actions such as lubricating parts, reading markings, and installing gland tabs must take place as the seal is being installed, requiring maneuvering in confined spaces. Installation is a simple process of bolting the two cartridge halves together, greatly reducing the amount of time spent hunched over a pump.
Tools needed to repair/rebuild a component – style split seal can include vice grips, an arbor press, rubber mallet, and channel lock pliers. No tools needed to repair the Style 85! Just use the enclosed Allen wrenches to install the fully assembled and pressure tested split seal.
Repairing a component-style split seal in the field requires the operator to analyze the components in an attempt to determine and correct the cause of failure. This process is only as successful as the operator’s knowledge and experience. Flexaseal offers a failure analysis service, including suggestions to improve seal run time. These analyses utilize our years of engineering proficiency and are included in the purchase of every Flexaseal Style 85.
A component-style split seal must be removed to make any impeller adjustments. Once the adjustments are complete, the entire seal installation process must occur again before the pump can be restarted. The Flexaseal Style 85 design allows you to easily adjust the impeller without dismantling the seal. Simply reinstall the set clips, loosen the set screws and readjust the impeller position. When you’re finished, tighten the set screws and remove the clips!