Piping pressure testing

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Safety Renovation Project of Jinling DSM Resins Co., Ltd. – Mechanical and Electrical Installation Works, Pressure Testing of Process Piping – Technical Plan
Prepared by: Reviewed by: Approved by: Sinochem Sixth Construction Group Third Branch
February 2007

Table of Contents
1. Preparation Notes
2. Project Overview
3. Pressure Testing of Process Piping
4. Safety Technical Measures
5. Labor Plan
6. List of Main Equipment
7. Material Plan for Pressure Testing Methods Used in Pipe Testing
8. List of Pipe Testing and Pressure Testing Systems
9. Diagram of Pipe Testing and Pressure Testing Systems

1. Preparation Notes
1.1 This plan serves as a technical scheme for the pressure testing of process piping and equipment as part of the mechanical and electrical installation works for the safety renovation project of Jinling DSM Resins Co., Ltd. 1.2 Basis for the preparation of this plan 1.2.1 Project contract ； 1.2.2 Process pipeline installation plan ； 1.2.3 \"Code for Construction and Acceptance of Metal Piping Projects\" GB50235-97 1.2 4 \"Code for On-site Equipment, Industrial Piping, Welding Construction and Acceptance\" GB50236-98 2 Project Overview 2.1 Jinling DSM Resins Co., Ltd. conducted a safety assessment of its composite resin production facility by referring to the safety evaluations carried out at DSM’s composite resin plants in Europe. It was found that the current safety level of the facility does not fully meet the relevant local regulations, nor does it satisfy the SHE requirements set by Jinling DSM. According to the safety assessment report, the potential risks associated with the facility are not adequately addressed through safety measures in line with relevant standards; therefore, it is necessary to carry out relevant process modifications and install a safety instrumented system (SIS) in the facility. At present, the plant is operating at full capacity. The schedule for the process modifications and the installation of a new set of safety instrument systems is as follows: technical preparations will begin on January 18, 2007; mobilization for the work will start on February 1, 2007; all materials will be secured by February 15, 2007, and pipeline prefabrication will be completed by then ； Production was halted on March 11, 2007; by April 1, 2007, the process was modified and a safety instrument system was installed, along with modifications to the process pipelines. 2.2 Main construction procedures 3 Pressure testing of process pipelines 3.1 The following conditions must be met prior to carrying out the pressure test: 3.1.1 The pipeline installation work within the scope of the test, except for painting for insulation purposes, must have been completed in accordance with the design drawings, and the quality of the installation must meet relevant regulations. 3.1.2 The welds and other areas to be inspected have not yet been painted or insulated. 3.1.3 The pressure gauges used for testing have been calibrated and are within their periodic inspection period; their accuracy must be at least 1.5 grade. The full scale value of the gauges should be 1.5–2 times the maximum pressure to be measured, and there must be no fewer than two such gauges. 3.1.4 The liquid pipelines that meet the pressure test requirements have been connected. 3.1.5 The pipeline has been reinforced in accordance with the test requirements. 3.1.6 The pipeline to be tested has been isolated from unrelated systems using blind flanges or other measures. 3.1.7 The safety valves, rupture disks, and instrumentation components on the pipeline to be tested have been removed or isolated. 3.1.8 The test plan has been approved, and the technical details have been communicated. 3.2 The hydraulic testing shall comply with the following provisions: 3.2.1 Clean water shall be used for hydraulic testing; depending on the actual conditions at the site, circulating water or fire-fighting water may be used as the testing medium. 3.2.2 Before the test, air should be exhausted at lower positions while filling with liquid; a vent should be installed at the highest point. After each system is completely filled with water, a pressure gauge should be installed on the exhaust pipe, and another pressure gauge should be installed at the end of the pressure testing pump. 3.2.3 During testing, the ambient temperature should not be lower than 5°C; when it is below 5°C, anti-freezing measures must be taken. 3.2.4 During testing, the test temperature should be measured; it is strictly prohibited for the material’s test temperature to approach the brittle transition temperature. 3.2.5 Determination of test pressure. The specified test pressure as listed in the process pipeline characteristic table, which is a summary of pipeline characteristics, shall be applied. 3.2.6 For pipes with a large pressure difference, the static pressure of the test medium shall be included in the test pressure. In liquid pipelines, the test pressure shall be based on the pressure at the highest point, but the pressure at the lowest point shall not exceed the bearing capacity of the pipeline components. 3.2.7 During the hydraulic test, the pressure should be increased slowly. When it reaches 10% of the test pressure, the increase in pressure should be stopped; a thorough inspection should be carried out to check for any leaks in the flange bolts and gaskets. After that, the pressure should be raised to 50% and then to 75% of the test pressure. Each time a thorough inspection shows no leaks in the welds, the pressure can be increased further to the test level. The pressure should be held at this level for 10 minutes, after which it should be reduced to the design pressure. A final thorough inspection should be conducted, and the test is considered successful if the pressure remains stable and there are no leaks. (No time limit; a thorough inspection is carried out based on the system size and the length of the pipelines). Its test curve is as follows: 3.2.8 After the test is completed, the blind flanges and expansion joint restrictions should be removed promptly, and any liquid accumulated in the temporary pipelines should be drained. When draining, care must be taken to prevent negative pressure from forming, and the liquid must not be discharged indiscriminately. 3.2.9 During the testing phase, a dedicated person shall be responsible for conducting regular inspections of the entire pressure testing system; if any leaks or abnormal phenomena are detected, the pressure increase must be stopped immediately. The pressure must be reduced to fix the defects before testing can resume. Under normal circumstances, the pressure testing should be completed on the same day; if it needs to be carried out over night, the pressure inside the pipeline must not exceed the operating pressure. 3.2.10 The exhaust pipes, vent pipes, and sewage pipes within the device are not subjected to pressure testing. 4 Safety Technical Measures 4.1 Before carrying out the pressure testing, the construction technicians must provide technical and safety instructions to all personnel involved in the testing, and ensure strict compliance with the six safety rules and operating procedures. 4.2 There are numerous process pipelines to be pressure-tested, and the test pressures are high. The testing is carried out in an environment where construction is ongoing; therefore, it is necessary to protect the area designated for testing before starting the process. For the pipelines that are to be tested, other workers should be warned not to approach them, nor to strike them or place welding wires on them. 4.3 The pressure testing personnel must closely monitor the pipelines under pressure section by section, and must not leave their posts casually; any abnormalities should be reported promptly via walkie-talkie. 4.4 During inspection, the pressure testing personnel must not face the valve, the flange surface, or the blind plate surface, to prevent the test medium from spraying out and causing injury; any repairs that are necessary must be carried out after reducing the pressure. 4.5 The operator responsible for raising and lowering the pressure must control the speed of pressure increase in accordance with the pre-determined pressure testing curve, and pay attention to draining water and releasing pressure. 4.6 Before pressure testing, check whether all the scaffolding and inspection platforms set up in the system are secure; those that need to be rebuilt must be rebuilt, and those that require reinforcement should be reinforced promptly. 4.7 When removing flanges and installing blind plates, be cautious of personal injury caused by stress-induced deformation resulting from forceful assembly. The electric machinery used for pressure testing must be in good condition, and it must be equipped with leakage protection devices and overpressure safety valves. 5 Labor Allocation Plan: Job Type, Number of Workers. Pipe fitters: 4; Electricians: 2; Welders: 4; General laborers: 8; Gas welders: 2; Managers: 6; Riveters: 2; Cranes operators: 2. Total: 30. 6 List of Main Tools and Equipment: Serial number, Name, Model and specifications, Unit, Quantity, Remarks. 1. Grinding wheel machine, φ125mm, unit: set, quantity: 4. 2. Grinding wheel cutter, φ400mm, unit: set, quantity: 1. 3. Welding rod insulation sleeves, unit: piece, quantity: 15. 4. Valves, Z40H-10P DN25, unit: piece, quantity: 6. 5. AC welding machines, BX3-500, BX-330, unit: set, quantity: 2. 6. Oxygen cylinders and acetylene cylinders, unit: piece, quantity: 2 each. 7. Gas welding tools, unit: set, quantity: 2. 8. Electric pressure testing pump, SY320/40, unit: set, quantity: 2. 9. Pressure gauges, 0-2.5 Mpa, unit: piece, quantity: 6, accuracy class: 1.5. 7 Material plan for pipeline pressure testing ； Serial Number Material Name Model Specification Unit Quantity Remarks 1 Seamless steel pipe φ57*3.5 meters 60 2 Seamless steel pipe φ32*3 meters 60 3 Valve Z40H-10P DN25 pieces 6 4 Valve Z40H-10P DN50 pieces 4 5 Slip-on flange 50-10 pieces 12 6 Slip-on flange 32-10 pieces 12 7 Steel plate δ=12 M2 4 8 Steel plate δ=10 M2 5 9 Steel plate δ=8 M2 14 10 Gasket DN25-DN350 pieces 250 11 Bolt M20*70 sets 70 8 List of pipeline testing and pressure testing systems 9 Diagram of pipeline testing and pressure testing systems