A plan 53B is a pressurised piping system with a gas loaded accumulator (external reservoir) thatcontains a clean barrier fluid. The barrier fluid is re-circulated by a pumping ring in the seal chamber. It is typically used with pressurised dual (double) seals at a pressure greater than the box pressure. Thebarrier fluid provides cooling and lubrication for the inner and outer seal. The higher barrier liquid pressure results in barrier liquid leakage over the seal faces into the process, thus fully containing the product. The barrier liquid is pressurised by an inert gas (usually nitrogen) that is contained within the bladder of the gas-loaded accumulator.
Heat is removed by a natural air draught cooler or water cooler. For those applications where a pumping ring is not available or would offer an insufficient flow, HPS has available magnetically driven seal liquid circulation pumps that can be incorporated.
For most pressurised sealing configurations HPS would recommend the use of this type of sealing system.
Advantages of a 53B compared to a 53A system
The 53B uses a gas-loaded accumulator with physical separation between the gas and the barrier liquid, thus eliminating the risk of gas introduction at the seal faces.
Once charged the gas is contained for a longer period, eliminating the need for the often
quite expensive inert (nitrogen) gas pressurising and conditioning systems.
Gas loads to well over 200 bars can be accommodated eliminating the need for gas pressure boosting equipmentat high pressure services.
These units are easier to operate and maintain, built more compact and are better suited to accommodate the various types of heat exchangers and other constructional options.
Liquid refilling:
<Around every 2 to 6 weeks these units require a barrier liquid refill whilst in operation and pressurised, a potentially hazardous situation. For that purpose HPS developed the Flo-Pac HMS series Mobile make-up units, well suited for safe refill operations.
If you have an interest for these units, please browse our range of pre-engineeredunits or address your questions tosales@hpsbv.nl
