The main feature of the check valve is its compact size, safety, reliability and intelligence. It plays an important role in vacuum handling of objects. The check valve has been developed to complete the DVK series, with different power ratings, and the new check valve size is smaller, greatly reducing the space required for installation, and solving the problem that could not be installed due to space reasons. Reduced user costs and expanded use. Check valves play a decisive role in solving certain vacuum handling problems. For example, when handling objects of different sizes, there is no need to adjust the position of the suction cup because the check valve closes the suction cup that is not in contact with the object, thus The cost of adjusting the suction cup device is eliminated, making the vacuum handling work more economical and efficient. In addition, the check valve also functions as a safety device in the vacuum line. In the operation, if the vacuum leaks or the suction cup is disengaged from the object, the check valve is immediately closed, and the vacuum in the system remains unchanged. The built-in filter ensures that dust does not enter the vacuum system from the suction cup. When the object is blown off, the passage in the new check valve is wider, ensuring accurate release of the object. Thanks to the "intelligence" of the check valve, many handling problems can be solved at low cost.