... double road conveyor valves Double road transportation valve The Valve Series SK double road conveyor valvesTEL:0086-10-51259588 FAX:0086 ... transmission channel smooth, no jam, ensure fluid flow. S for worm gear type, D for electric transmission type, Y for electric hydraulic ... , feedback signals.Four, model establishment instructions SKK - 150 S worm gear, D electric, Y electro-hydraulic actuator