The WVS (Whatman Void Sealing) cartridge for Partisphere™ columns use a unique sealing system to ensure compression of the packed bed even if a void develops.
All of the WVS cartridge column products require the use of special end fittings (catalog # 66900-WEF) which are used for this purpose. The specialized design of this hardware system allows the user to hand-tighten the end fitting along with the frit as well.
What this means is that if a void develops in the column system, you can tighten the end fitting and frit which will re-compress the packed bed. In this manner, the void can be eliminated and the quality of the packed bed restored. These fittings can be re-used on other cartridge columns as well in case the column itself needs to be replaced.