... ISO9001, ISO140001 WFB series of non-sealing self-control self-priming pump is to fill the gaps ... , pressure, wear, "one drainage," "life-long self-absorption" and many other features. At present production ... uses: "a chain-type multi-faceted pump centrifugal sealing device", and to eradicate the traditional pump packing ... for the best. 2, run during the sealing device is not friction, no wear, longer ...