Diaphragm pump

A diaphragm pump comprising a pump body which defines internally at least one pair of pumping chambers which are connected, at an inlet, to at least one suction connector and, at an outlet, to at least one delivery connector of the pump, by means of the interposition of respective check valves, said at least one pair of pumping chambers being delimited by respective diaphragms separating said at least one pair of pumping chambers from respective actuation chambers, which is configured to be connected alternately to a source of compressed air by means of a power valve controlled by a pilot valve, provided with a sliding pad, which is pushed mechanically by said diaphragms and configured to move with a reciprocating motion within a pilot chamber, supplied with compressed air, in order to alternately connect said pilot chamber to a pilot port, connected to said power valve, or to a discharge port, connected to an outside environment, in said pump body there being an access opening adapted to allow access from outside to said pilot chamber and to said sliding pad, said access opening is configured to close by means of a closure element, wherein said closure element is configured to be removably fixed to said pump body, said closure element comprises a contact face which is configured to be inserted into said access opening and is designed to come into contact with said sliding pad, said pilot port and said discharge port being defined in said contact face, wherein said closure element comprises a main body made by molding and of plastic material and at least one plate-like element, which is coupled to said main body and defines at least one portion of said contact face, said at least one plate-like element being made of a material having, with respect to said sliding pad, a higher resistance to wear and a lower coefficient of friction than said plastic material.