open tender enquiry for supply on door delivery basis including loading and unloading of valves for diffuser system at hbl sugauli plant, east champaran, bihar 845456. supply on door delivery basis including loading and unloading of valves for diffuser system at hbl sugauli plant. , supply on door delivery basis including loading & unloading of valves for diffuser system make : hydac at hbl sugauli plant as per below details. , directional control solenoid operated valve : 4 we 10 d a01-24 dg / v, hsn code : 84819090, make : hydac. , directional control valve, solenoid operated type : 4we 6 d a01-24dg / v, hsn code : 84819090, make : hydac.