My friend, In this posting we will discuss about the pump recycle systems. The pump shall be protected from minimum flow, due to the following reasons;
1. Thermal consideration which has effect to the pump efficiency (The efficiency will decrease significantly at low flow)
2. At low flow, Internal recirculation will be occurred
3. Increase load impeller (both axial and radial)
4. liquid containing a large amount of abrasive particles must flow continuously through the pump. at low flow, the particles can circulate inside the pump and erode the impeller.