Please specify which pump you have. Parker pump packages come with additional fittings for the tank return line. 
Don’t let undersized lines kill your pump! 
Eliminate all pump killing restrictions to your hydraulic pump with our suction line kit. 
This kit has shown an increase in tracking speed by increasing flow and reducing intake pressure to the pump. 
This kit includes fittings, hose, instructions, bung, and an in-tank magnet for machines fitted with a casappa pump.
Welding is required. Welding a bung onto your hydraulic tank is the only way to ensure your system will not leak. If you cannot weld, then a pro can do it inexpensively.