These combine in them the two-fold features of suction and pressure and hence the same unit can be employed for either function. When used as vacuum pump, they can create vacuum up to 710 mm (28" Hg) provided the temperature of the sealant water is below 30 °C & barometric pressure at site is 30 Inches of Hg. Generally, the main casing & almost all the components are fabricated from C.I. except the main shaft, which is of MS / EN-8. However, it is also offered in various combinations of resistant materials for specific applications. Details are supplied on demand. One of the main characteristics of DHVE water-ring pumps is that even under harsh conditions or under lack of proper supervision, these pumps continue to give satisfactory performance because none of its internal parts demand greasing or lubrication. These are least affected if a small quantity of vapour, dust, gas, or other such impurities enter its body through the suction nozzle. Applications These are best suited for pharmaceutical, Food, Confectionery, Petro-chemicals, Textiles and plastic industries, Paper and Sugar mills, Cement, Metallurgical Laboratories and Furnaces, Refrigeration Plants, Distilleries, Pneumatic Conveying, Cigarette, Tiles and Ceramics industries etc. These pumps are approved for government, semi government and private industrial projects all over India.