Steel Body - The 1116 Series is built with zinc plated steel bodies to ensure a top level of strength and durability, these valves can reach a work pressure of 400 bar. N1116 Series - This valve controls a moving load preventing if from moving ahead of the pump and locks the load in any position on U1 and U2. It also provides static overload and thermal expansion protection when used in combination with an open centre spool valve. It permits free flow from D1 to U1 and D2 to U2 and blocks the flow from U1 to D1 and U2 to D2 until a pilot pressure generated at D1 or D2 is sufficient to pilot the U1 or U2 port open. This model is sensitive to back pressure on D1 and D2 in return mode. R1116 Series - As per N1116 but is insensitive to back pressure on D1 or D2 in return mode.