What is a pumping ring

[MarkkraM]

Hi,
I looking at plan 53 for providing buffer fluid to a pump seal. One option for circulation of the buffer fluid is using a pumping ring. Could someone please tell me what a pumping ring is and how it works.

Thanks,
MarkkraM

 

[Torricelli]

In Plan 53 the barrier or buffer fluid has to be circulated for cooling and in order to avoid varnishing and coking problems between the two seals.

This circulation can be induced
- by natural convection (thermosiphon) using a convection tank / cooler (the natural circulation is then due to the difference of density between cold leg and hot leg.)
- or/and with a pumping ring (springs inducing a forced circulation)

A pumping ring is very necessary
- for fluids with a low specific heat and a poor conductivity (like oils).
- to remove the large amount of frictional heat (when using two tungsten carbide faces as the inboard set in a dual seal arrangement)

Most of the newer cartridge dual seals come equipped with a built-in pumping ring inducing a forced recirculation and a better heat removal.

Hope it helps,
Torricelli

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