Within the Plan 53A system the pressurised barrier fluid is set a higher pressure than the process fluid pressure, typically 2 barg (30 psig). This optimises seal face longevity as it helps to ensure clean, cool barrier fluid between the counter rotational seal faces.
In summary, Plan 53A is a relatively simple but very effective reliability focused tool for rotating equipment uptime. As such, if you want to adopt best practice techniques at your plant, the start point is nearly always "install a double cartridge mechanical seal and a Plan 53A system".
Double Cartridge Seals (Rotary) = RPW516,
Double Cartridge Seals (Stationary) = SPW516,
API682 Double Cartridge Seals = SPW682-53,
For further reading on API Plan 53A seals and systems, please click the following links to related Technical Blogs;