Description Diameter: S60x6 Closure with valve Outlet: S60 x 6 male, standard tank valve outlet The 1000 liter IBC/GRV tanks are all fitted with a lower male threaded outlet where a drain valve is screwed on. it is therefore advisable before any purchase of valves to take the measurements of this outlet on your tank. To take the measurements correctly, it will be wise to equip yourself with a caliper beforehand, or failing a meter. The dimension D1 corresponds to the OVERALL diameter of the male outlet, and the dimension P1 to the spacing between two threads if: D1 = 60mm P1 = 6mm then your tank has an S60x6 outlet, you will need to buy a replacement valve with an S60x6 nut to make it compatible with your tank