Ana amfani da injin mai cike da famfo piston don cika ruwa daban-daban a cikin kwalabe, gwangwani, kofuna, bokiti da sauran kwantena. Hakanan ya dace da samfuran ruwa mai ɗanɗano ko kauri, kamar mai dafa abinci, man lube, abin sha, ruwan 'ya'yan itace, miya, manna, kirim, zuma, shamfu, wanka, magungunan kashe qwari, da taki mai ruwa da sauransu muddin yana iya gudana. Dangane da girman girman cika daban-daban da buƙatun ƙarfin cikawa, muna da nau'ikan injin iri daban-daban, kuma suna iya keɓancewa dangane da buƙatar abokin ciniki na musamman.