Delavan PowerMAX 30 GPM Mono-Block Directional Control Valve, 2 Spool W/ 1st Position Float. Delavan PowerMax Cylinders, Mono-Block and Kick-Off Valves are designed and manufactured to meet the most demanding requirements. Constructed of high tensile strength gray cast iron. Load check on each spool to prevent the fall of a cylinder as the spool is shifted. Hard chrome plated spool. Built-in relief valve adjustable from 1,500 to 3,000 PSI, preset at 2,100 PSI. 2 Spool With Float Spool available at 1st position ? allows the blade to follow the contour of the ground while leveling or plowing.