Abstract: A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine; the pump unit (1) comprising: a head (4) inside which a cylinder (12) extending along an axis (A1) is formed; a pumping piston (5) extending along the axis (A1) and slidingly coupled with the cylinder (12); a through-hole (13) which extends from the cylinder (12) towards the outside of the pump unit (1); an intake chamber (8) communicating with the cylinder (12) via the hole (13); an intake valve (7) which controls the flow of fuel from the intake chamber (8) to the hole (13); a cap (23; 123; 223) which is connected to the head (4), is arranged on the opposite side to the pumping piston (5) and can be selectively fixed along an outer surface (25) of the head (4) so as to close the intake chamber (8) on one side.

Abstract: A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine; the pump unit (1) comprising: a head (4) inside which a cylinder (12) extending along an axis (A1) is formed; a pumping piston (5) extending along the axis (A1) and slidingly coupled with the cylinder (12); a through-hole (13) which extends from the cylinder (12) towards the outside of the pump unit (1); an intake chamber (8) communicating with the cylinder (12) via the hole (13); an intake valve (7) which controls the flow of fuel from the intake chamber (8) to the hole (13); a cap (23; 123; 223) which is connected to the head (4), is arranged on the opposite side to the pumping piston (5) and can be selectively fixed along an outer surface (25) of the head (4) so as to close the intake chamber (8) on one side.

Abstract: A fuel safety valve arranged in a fuel supply line between a low-pressure pump and a high-pressure pump, is provided with a valve body which defines a cylindrical cavity having a longitudinal axis and being connected to a duct and a portion of a discharge duct in communication with the cylindrical cavity, a piston sliding with respect to the valve body in the cylindrical cavity along the longitudinal axis, and a spring housed in a variable-volume chamber defined by a portion of the cylindrical cavity between the piston and a closure element. The piston is provided with a through hole supplied with the fuel leading into the variable-volume chamber, and the valve body being provided with a fuel discharge hole connecting the variable-volume chamber to the discharge duct.

Abstract: A fuel safety valve arranged in a fuel supply line between a low-pressure pump and a high-pressure pump, is provided with a valve body which defines a cylindrical cavity having a longitudinal axis and being connected to a duct and a portion of a discharge duct in communication with the cylindrical cavity, a piston sliding with respect to the valve body in the cylindrical cavity along the longitudinal axis, and a spring housed in a variable-volume chamber defined by a portion of the cylindrical cavity between the piston and a closure element. The piston is provided with a through hole supplied with the fuel leading into the variable-volume chamber, and the valve body being provided with a fuel discharge hole connecting the variable-volume chamber to the discharge duct.