... non--sealing 2.self --control 3.self --priming pump Features:Property:WFB series non - sealing self - control and self - priming pump, ... protection, fire fighting, municipal services, water clean, national defense industry, textile printing and dyeing, mining mineral processing, civil ... control valve", achieves "once - priming, life - long self - priming."4.Small vibration, low noise, flexible move, ...