Check valve

A check valve (1) for installation on a delivery port (2) of a centrifugal pump (3) in a pump system, said check valve (1) comprising:

• a valve body (4) with an inlet portion (5) and an outlet portion (6) for a fluid (F), the inlet portion (5) and the outlet portion (6) being joined together by a guiding duct (7);
• a connection curve (8) coupled to said valve body (4) and having an inlet end (9) for the fluid (F), adapted to be connected to the delivery port (2) of the pump (3), and an outlet end (10) adapted to be connected to said valve body (4);
• and
• a valve member (18) associated with said valve body (4), said valve member (18) being made of a flexible material and being movable between an open position and a blocked position in which said guiding duct (7) is automatically blocked;
• wherein said valve body (4) has an inspection opening (19) with a closing lid (20) configured to be opened from outside;
• wherein said valve member (18) comprises a flap- and disk-shaped blocking portion (22) which is intended to sealingly interact with a projecting edge (24) of said connection curve (8) that projects into said valve body (4), and a locking portion (25) held in a matingly shaped seat (26), which is only formed in said body (4), and secured therein by said closing lid (20);
• and
• wherein said flap- and disk-shaped blocking portion (22) comprises a core (23) made of a metal material and said locking portion (25) is free of any metal material, said closing lid (20) being configured to cooperate with said locking portion (25) via a protrusion or a cavity (31) to push said valve member (18) toward the outlet end (10) of said connection curve (8) in said blocked position and to allow said valve member (18) to deflect toward an interior of said valve body (4) to said open position under pressure of the fluid (F) in equilibrium with a weight of said blocking portion (22).