... 2).ISO9001, ISO140001 WFB series of non-sealing self-control self-priming pump is to fill the gaps of the first ... , in particular, used the term "electric air control valve", truly a "one-draining, life-long self-priming." 4, little vibration, low noise ... to install, no need to foot fixation. 5, with excellent self-control function, and high-tech areas and supporting the use of ...