Hydraulic Valve To Adapt To A Wide Range
The nominal flow (also called nominal flow) passed by the hydraulic valve under rated operating conditions is called nominal flow and is expressed in qg or Qg. It marks the hydraulic valve flow capacity, Hydraulic Valves mainly used to indicate the medium and low pressure hydraulic valve specifications. China's hydraulic valve nominal flow of commonly used legal units of measurement using L / min (l / min) or m3 / s (m 3 / s).
The nominal size of the inlet and outlet of the hydraulic valve (not the actual size of the import and export) is called the nominal diameter and is denoted by Dg. Nominal diameter contains the nominal size of the main port of the valve, the size of the size and size of the installation surface of the three-tier significance, Hydraulic Valves mainly used to indicate the specifications of high-pressure hydraulic valve.
China's hydraulic valve nominal diameter of the commonly used legal units of measurement using mm (mm). In order to correspond to the specifications of the connecting pipe, the nominal diameter of the hydraulic valve uses the nominal diameter of the pipe (nominal diameter of the pipe) series of parameters, so the valve diameter once identified, the matching pipe specifications are selected. Because the actual size of the main port of the hydraulic valve is limited by the parameters such as the flow velocity and the structural characteristics, the actual size of the main port of the valve is not necessarily the same as the nominal diameter. In fact, Hydraulic Valves the nominal diameter is only used to indicate the size of the hydraulic valve, so the actual size of the two main types of hydraulic valves (such as directional valves and pressure valves) with different functions but with the same diameter specifications may not be the same.
Hydraulic valve manufacturing process, in order to improve the accuracy of the assembly more use of matching methods, that is, a number of finished parts, such as valve body and spool, according to the actual size of the gap with the most appropriate choice of a pair of assembly to ensure good Spool sliding and sealing performance. In other words, the same type of hydraulic valve, valve core and the valve with the size of a certain difference for the use of enterprises, when a number of failure of a number of hydraulic valves, you can remove all the valve cleaning, inspection and measurement of the parts, According to the test results will be classified parts, according to the following methods re-combination of matching.
If the spool, the valve body is evenly worn, Hydraulic Valves the working surface is not severely scratched or severely worn, then in accordance with the manual, select the appropriate gap with the spool, the valve re-assembly; if the spool, the valve body wear is not Uniform or work surface scratches, through the above method has been unable to restore the hydraulic valve function, then select the processing margin to meet the requirements of the amount of interference a pair of spool, the valve body (small hole size and large diameter Spool), the valve body hole reaming or grinding, the spool grinding, to achieve a reasonable shape accuracy with the assembly after the accuracy. Common hydraulic valve valve hole shape accuracy and with the gap
Recovery dimension maintenance method
The use of parts matching method to repair hydraulic valve although the process is relatively simple, but its limitations, and the use of repair size rules to adapt to a wider range of occasions. Hydraulic Valves Simple and feasible repair size method is mainly to replace the parts and repair method two categories.
Replace the parts method is to have lost the accuracy of the spool disassembly, measurement and drawing parts diagram; check the valve body guide hole or seat wear or damage, and thus determine the amount of repair processing, and then finishing (fine hinge Or grinding) repair. Hydraulic Valves For a seat with a certain taper, make a specific machining tool. After processing to the appropriate accuracy, measure the actual size, and then according to the size of the new valve core processing. This maintenance method of high precision, wide adaptation, can be completely restored to the original accuracy, suitable for a certain processing capacity of the enterprise.
Repair repair a lot of types of technology, Hydraulic Valves suitable for hydraulic valve repair the most common method for the brush plating or called electroplating. Electroplating reasonable repair thickness of less than 012mm, basically meet the uniform wear hydraulic valve maintenance requirements, repair still need to follow-up processing. Commonly used electroplating process is a chemical composite electroplating, chemical composite electroplating is developed on the basis of mature plating process, with a simple equipment, easy operation, low cost, easy to control the advantages of the reaction, the process can be in the valve The core or valve surface is deposited with a composite coating with a variety of ingredients. The coating is firmly bonded to the parent metal and has high mechanical strength, excellent thermal conductivity, low coefficient of thermal expansion, low coefficient of friction and strong self Repair ability. Formulation and Process Conditions of Typical Chemical Composite Plating Bath