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  • Writer's picturekatiejobson


Updated: Mar 2, 2023

Depending on the pump type and the process variables, there are various mechanical seal types to choose from. Each seal variant has its unique design and characteristics which make it suitable for a specific application. In this post, we'll discuss when a split cartridge mechanical seal is most appropriate.

What is a Split Cartridge Mechanical Seal?

Alumina Refinery seawater intake pump split seal installation

A split cartridge mechanical seal comes in two separate pieces. Unlike ordinary cartridge mechanical seals, these two pieces can be installed or removed from around the shaft without disassembling the equipment. When joined, the sealing elements are mated to create a proper seal around the shaft.

When Should I Use a Split Cartridge Mechanical Seal?

Split cartridge mechanical seals are an innovative sealing solution for environments where it may be difficult to install or replace conventional mechanical seals, such as hard to access equipment. Applications such as this Alumina Refinery’s seawater intake pumps have an awkward stuffing box location requiring technicians to lie on their stomachs to

install / change out the mechanical seal. By converting to a split cartridge mechanical seal, it made the job easy for the technicians and reduced the installation time significantly.

Taking just minutes to install, they are also ideal for minimising costly downtime for assets critical to production by overcoming the assembly and disassembly difficulties associated with rotating equipment.

A common component seal replacement on a split-case pump would require removal of end bearings, motor coupling, and possibly the motor itself. These extra processes cause increased labor hours and increased down time, which in turn means increased cost. A split cartridge mechanical seal, however, can greatly decrease these liabilities.

Common applications for split cartridge mechanical seals are as follows:

  • Equipment with large shaft sizes

  • Vertical shaft pumps

  • Side-entry mixers & agitators

  • Double-suction pumps

These applications benefit from split cartridge seals because the equipment they are installed in require large amounts of time for disassembly. The use of split mechanical seals in these applications reduces install time, reduces sleeve wear, increases equipment reliability, and reduces maintenance costs. You can see how easy it is to install and get a glimpse of the manufacturing process by watching this video:

Due to the increase in initial cost for split mechanical seals, it is best to implement them in your system when the savings from the above mentioned benefits outweighs the increase in initial cost. In most cases, the savings can be quite significant.


­­­­ Specialised Flow Solutions is the Australian distributor for Flexaseal, a leading U.S. manufacturer of custom engineered mechanical seals, welded metal bellows and the two-piece split cartridge mechanical seal.

If you are not sure which mechanical seal configuration is right for your application, ask us about it! We gladly provide technical assistance to pump repairers and end-users Australia wide.


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