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Document Number: Tech. Argument _001 – Instructions for Repairing Helbig Air Valves. To save costs and make the best use of resources, Helbig includes a certain amount of machining tolerance in the design of its air valves, allowing them to be machined multiple times and reused. To ensure maintenance quality, carbon steel or cast valves used in corrosive media are not repaired. A professional and rigorous set of procedures is essential to ensure the quality of valve repairs. To help you understand the process used by Holberg for repairing valves, we present our company’s repair procedures as follows: 1. Disassembly – The valves are disassembled using Holberg’s specialized assembly and clamping devices. To ensure reliable clamping between the valve seat and the valve cover, relative rotation is not allowed, as this could cause the guide pin to bend or break. 2. Valve condition assessment: Assess the condition of the valve by making a preliminary judgment on the damage to components such as the valve seat, valve cover, and center bolts. The identification work is carried out by experienced experts from our company. 3. Cleaning: In a cleaning tank that meets environmental requirements, the air valves are cleaned of oil using special soft brushes. After cleaning, the valve seat and valve cover also need to be polished. 4. Inspection: Check the valve seat and valve cover surfaces for defects such as cracks and dents. And ultimately, an assessment report on the repairability of the valve seat and valve cover is provided. 5. Finishing: The valve seat and valve cover are processed using precisely controlled CNC machines, rather than through simple grinding. Throughout the refurbishment process, it is not allowed to change the lift of the valve disc; the strength of the valve seat must meet the required standards, and it is also essential to ensure that the valve can be installed properly after maintenance. 6. Assembly: Replace all valve plates, buffer plates, springs, spring sheets, self-locking nuts, split pins, anti-loosening washers, and other components, and use specialized valve assembly tools for the assembly process. 7. Inspection: Check all relevant design and installation dimensions of the air valve according to the drawings; if they exceed the tolerance limits, it is necessary to verify again whether this affects installation. The assembled gas valves must also undergo a leak test in accordance with the Helbig leakage testing standards, to ensure that each repaired valve can be used directly just like a new one. 8. Rust prevention or degreasing: For air valves not used in oxygen compressors, rust preventive oil should be applied to prevent rust. For the air valves used in oxygen compressors, it is essential to ensure thorough oil and grease removal. 9. Packaging: It is packaged using vapor-resistant anti-rust packaging paper that meets environmental requirements. 10. Marking and labels: Mark the number of times of maintenance on the valve body. Indicate on the label of the air valve packaging: maintenance date, drawing number, type, quantity, and contract number. By carrying out professional repairs on old valves in accordance with the aforementioned process, Holbigg ensures that the repaired gas valves achieve the same quality as new valves, thereby enabling the highest possible efficiency in using these gas valves at the lowest cost.