The series of DESMI MODULAR S pumps represents one of the most distinctive developments in self-priming pumps. The individual design, compact with a clear-cut cylindrical form, together with the practical advantages such as easy assembling and MODULAR construction of all components ensure a long a trouble-free operation. MODULAR S can pump a mixture of air and liquid and thus evacuate air from the suction pipe. Thus, priming can be avoided and a foot valve is not necessary.