SDI Sandwich Hydraulic Diaphragm pumps are manufactured according API 675. SDI pumps are suitable for use when: – the liquid to dose contains small amounts of suspended solids – the dosed liquid is a toxic solution – liquid leaking are not accepted. A built-in safety valve is installed in the hydraulic circuit, in order to protect the diaphragm against over pressure. The peculiarity of this pump is the special sandwich diaphragm and the reliability of the diaphragm rupture detection system. Accuracy is better than 1% from 10 to 100% of the stroke adjustment.