The last
millimetre.
Everything a pump does depends on a gap a few microns across, between two rings of ceramic or carbide. This is what is inside a mechanical seal and why each piece is there.
Components
Select a component to see what it does. Drag the slider to pull the assembly apart.
How it works
01
The problem
A pump has to turn a shaft inside a casing full of liquid. Wherever that shaft passes out through the casing there is a gap, and the liquid is under pressure. Something has to close that gap while still letting the shaft turn.
02
Two flat faces
A mechanical seal closes it with two rings pressed together, one turning with the shaft and one held still. Their contact faces are lapped flat to within a fraction of a wavelength of light — flat enough that the gap between them is measured in microns.
03
The film
The faces never quite touch. A film of the pumped fluid, drawn between them, carries the load and takes the heat away. Too thick and the seal leaks; too thin and the faces run dry and destroy themselves. The whole design is an argument about that film.
04
Why it matters
The seal is usually the smallest and cheapest part of a pump, and the one that decides whether the pump runs. Selection is not a catalogue lookup — it depends on what is being pumped, how hot, at what pressure, and how fast.
Tell us what you are pumping.
Media, temperature, pressure, shaft size and speed. From those five figures our engineers can specify faces, elastomers and metallurgy for the duty.