Flange type oil discharge structure for fluid end of three-cylinder single-action diaphragm pump

The utility model relates to a flange type oil discharge structure of a fluid end cavity of a three-cylinder single-action diaphragm pump, in particular to a flange type oil discharge structure of the fluid end of the three-cylinder single-action diaphragm pump. The utility model provides a novel flange type oil discharge structure which is particularly suitable for a cavity and an oil cylinder of a large-flow three-cylinder single-action diaphragm pump, the oil discharge efficiency can be obviously improved when the oil quantity of propulsive liquid is large, and the service life of a pressure-bearing cavity at a fluid end can be guaranteed due to the fact that internal threads are machined at the position of a connecting flange. The oil drainage device comprises a cavity and is characterized in that an installation platform is arranged on the side of the cavity, an oil drainage hole communicated with the interior of the cavity is formed in the installation platform, and threaded blind holes are formed in th