Valve warehousing management?

1. Place the small valves on the shelves, while the larger valves can be arranged neatly below; make sure that the flanges do not touch the ground. 2. Be careful when handling them to avoid breaking the handwheels or misaligning the valve stems. 3. For valves that are not in use, remove the asbestos packing to prevent corrosion of the valve stems. 4. Before storing new valves, clean any dirt and water from inside them. 5. Seal the inlet and outlet ports of the valves with wax paper or plastic sheets. 6. Valves that are prone to rusting in atmospheric conditions should have their mating surfaces coated with anti-rust oil. 7. The warehouse should be kept clean and tidy

Table of Contents 1 General Provisions 2 1.1 Scope of Application 2 1.2 Classification of Process Piping and Valves 2 2 Integrity Standards 2 2.1 Components and Parts 2 2.2 Technical Documentation 3 2.3 Equipment and Environment 3 3 Equipment Maintenance 3 3.1 Routine Maintenance 3 3.2 Regular Inspection Items 3 3.3 Methods for Handling Common Faults 3 3.4 Emergency Shutdown 4 4 Inspection, Maintenance Periods, and Tasks 4 4.1 Inspection and Maintenance Periods 4 4.2 Inspection and Maintenance Tasks 4 5 Maintenance Methods and Quality Standards 5 5.1 Materials 5 5.2 Fabrication Drawings for Pipes, Fittings, and Fasteners 5 5.3 Pipe Welding 6 5.4 Pipe Dismantling and Installation 8 5.5 Valve Maintenance. 10 5.6 Pressure Resistance Test 11 5.7 Online Sealing 11 6 Commissioning and Acceptance 12 6.1 Preparations before Commissioning 12 6.2 Commissioning 12 6.3 Acceptance 12 7 Safety Precautions for Maintenance and Repair 13 7.1 Safety Precautions for Maintenance 13 7.2 Safety Precautions for Repair 13 7.3 Safety Precautions for Strength and Tightness Tests 13 1 General Provisions 1.1 Scope of Application 1.1.1 These regulations apply to the maintenance and repair of process pipelines as well as process valves made of carbon steel, alloy steel, stainless steel, and heat-resistant steel in chemical plants, where the operating pressure is below 35 MPa and the operating temperature ranges from –20 to 450°C. 1.1.2 This specification may be referred to for the maintenance and repair of processes and thermal pipelines operating at temperatures below –20°C or above 450°C, as well as high-pressure pipelines with a maximum operating pressure greater than 35 MPa. 1.1.3 High-pressure pipes in externally introduced and replicated design devices ； Those designs without specific requirements can also refer to these regulations. 1.2 Classification of Process Piping and Valves 1.2.1 Classification of Piping 1.2.1.1 Piping is classified based on nominal pressure as the main parameter, as shown in Table 1. Table 1 Category Nominal Pressure P, MPa Category Nominal Pressure P, MPa Vacuum Piping Low-pressure Piping P＜0 0≤P＜1.6 Medium-pressure Piping High-pressure Piping 1.6＜P＜10 P＞10 Note: When both the operating pressure and operating temperature of the piping are relatively high, the maximum operating pressure and temperature should be converted into nominal pressure before using this table to determine the category of the piping. The nominal pressure values in the table can be found in Appendix 1, Appendix 2, and Appendix 3. 1.2.1.2 The classification of pipes by material and operating parameters is shown in Table 2. Table 2 Materials, Operating Temperature (°C), Operating Pressure, MPa I II III IV V Carbon steel 36 600~650 12Cr1MoV ZG20CrMoV ZG15Cr1MoV ≥6 200~300 250~300 >6 720~700 15CrMo ZG20CrMo ≥10 ≥6 150~200 200~300 >10 600~700 12Cr2MoWVB 12Cr3MoWVSiTiB Cr5Mo ≥6 250~350 Any 750~780 Note: 1. When the welding environment temperature is below 0°C, all metals for which no preheating requirement is specified in the table should be appropriately preheated so that the base metal to be welded feels warm to the touch ； For the metals specified in the table as requiring preheating, the preheating temperature should be increased appropriately. 2. Carbon copper and alloy steel welds subject to stress corrosion shall undergo post-weld heat treatment, regardless of their wall thickness. 3. For the post-weld heat treatment of welded joints in armament categories, it should generally be determined based on the steel material with the lower alloy content. 5.3.4 Welding Inspection 5.3.4.1 After welding pipes, the welds must be inspected visually. Before this inspection, any slag or spatter that could obstruct the view must be removed. The visual inspection should be carried out prior to non-destructive testing, strength testing, and leak testing. 5.3.4.2 The surface quality standards for welds at pipe butt joints vary depending on the weld grade, as shown in Table 7. 5.3.4.3 The internal quality of pipeline welds shall be inspected by non-destructive testing in accordance with the design specifications; if no such specifications are provided, the number of radiographic inspections required for the welds shall be determined as per Table 8. 5.3.4.4 The internal quality standards for pipeline welds are shown in Table 9. 5.3.4.5 Welds that are found to be defective upon inspection must be reworked. Number of rework cycles per weld: For carbon steel, it must not exceed three times ； Alloy steel and stainless acid-resistant steel are not allowed to exceed two times. Any returns exceeding the specified number must be approved by the technical supervisor of the welding unit. 5.3.4.6 Welds of high-pressure pipelines that fail the inspection must be reworked, and 100% flaw detection testing must be conducted after the rework. The number of repairs for each weld shall not exceed two times. ； 5.3.4.7 If the weld inspection results for medium and low-pressure pipelines are unsatisfactory, they shall be handled separately according to the following circumstances: a. When the number of non-conforming items is 30% or less of the total number inspected, and their defects fall between the acceptable standard and the standard one level below it, only the non-conforming areas are repaired ； b. When the number of non-conforming items exceeds 30%, double testing shall be carried out; if there are still non-conformities after double testing, testing shall be performed on all items. All non-conforming areas must be reworked ； c. All repaired welds shall be re-inspected. 5.3.4.8 High-pressure pipes after welding shall undergo a pressure test in accordance with the provisions of Article 5.6 of these regulations. 5.4 Dismantling and Installation of Pipelines 5.4.1 For pipelines carrying flammable, explosive, toxic, or harmful media, they should be isolated from the production system using blind flanges prior to maintenance, and maintenance can only proceed after the pipes have been properly cleaned and purged. 5.4.2 When removing bolts at working temperatures above 300°C, the temperature should be reduced to around 150°C before applying oil ； The bolts should be removed from bottom to top, and cleaned with kerosene after removal. 5.4.3 The removed pipes, or the new pipes, fittings, fasteners, valves, etc. that are used as replacements, should be stored properly before installation to prevent damage. Special attention should be paid to the threads and sealing surfaces, which must be thoroughly cleaned; no debris should remain there. Table 7 Code Item Weld Grade Code Item Weld Grade I II III IV I II III IV 1 Not allowed Not allowed 2 Depth: e1