Hydraulic-control Check Valve (For power incline, rear ripper (optional), front scraper blade (optional)) 1. Check Valve 2. Piston 3. Shell Body 4. Check Valve 5. Overflow Valve The hydraulic-control check valve with safety valve is mainly prevent the pressure variation of hydraulic cylinder and protect hydraulic cylinder from occurring abnormal pressure due to the foreign force. Operation When operate the operation rod to extend the oil cylinder, the oil enters into A 1 chamber from oil pump and pushes the piston (2) and the check valve (4), then the oil flows to the bottom of hydraulic cylinder through B 1 chamber.
The oil on the head of oil cylinder back to oil tank from B 2 chamber and A 2 chamber. When operate the operation rod to retract the oil cylinder, the oil enters into A 2 chamber from oil pump. When the pressure of A 2 chamber is increased, the check valve (1) is pushed and opens the check valve (1). The oil flows to the head of hydraulic cylinder from B 2 chamber. When the pressure of B 2 chamber is increased to abnormal value of 250 kg/cm 2 or more due to the impact, the overflow valve will be opened and oil flows from B 2 chamber to B 1 chamber, which reduce the impact. 20-113