1. Reduce the electro-hydraulic valve control pressure 2. commutation control line or the return line in the road an additional selection of components with pilot throttle 3. unloading function 4. Using electrical control method of hydraulic maintenance organizations, make two or more 3. The reversing valve air can not enter the well discharge air vibrations 1. (1) must be able to form a sealed working space caused by the hydraulic cylinder, the volume can do periodic variation. (2) There must be coordinated with the volume change with flow mode. 2, hydraulic pump type structure can be divided according to their gear pumps, vane pumps, piston pumps and screw types. Whether the change in output flow can be divided dosing pumps and variable pump. Press the oil can change the direction of the hydraulic pump can be divided into one-way and two-way pump pumps. Hydraulic repair quote | Xi'an Chengtong hydraulic repair | hydraulic service provided by the Xi'an Xi'an Chengtong hydraulic repair Limited. Xi'an Chengtong Hydraulic Maintenance Co. (www.huosu360.com) is Xi'an, industrial maintenance, installation of leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Xi'an Chengtong hydraulic service leadership with the staff warmly welcome all inquiries negotiations to create Xi'an Chengtong hydraulic repair a better future.