2022-12-05 16:20:28
The electromechanical installation equipment manufacturer will explain to youElectromechanical engineering installationTechnical aspects and pipeline engineering installation and construction processes:
1. Electromechanical Engineering Installation Technology
Details of the key integral time constant for the distribution unit
1. Overcurrent maintenance integral time constant—current component integration time constant and time component integration time constant 2. Overload alarm integration time constants — overload current component integration time constants and time component integration time constants 3. Overvoltage maintenance time constant—overvoltage range integer time constant and overvoltage maintenance time constant 4. The three-phase primary reclosing time constant — the reclosing delay time constant and the reclosing current angle time constant are 5. Zero-sequence current maintains the integration time constant—the time constant of the current component, time component, and direction component
Transformer operation switching experiment
1. Winding resistance is measured together with the waterproof sleeve resistance
2。 Measure the grounding resistance of the transformer core and clamp 3. Measure winding resistance and the grounding resistance and absorption ratio of the waterproof bushing. 4. Insulating oil test or SF6 gas test 5. 6. AC voltage test for communication of insulated waterproof sleeves. The rated current impulse closing test checks the voltage ratio of all No. 8 taps. Check the three-phase electrical connection group of the voltage tester. Inspection phase
Transmission line connection requirements
Each transmission line can have only one connector per pitch. 2. Transmission lines of different materials, profiles, or torsion directions can only be connected via jumpers. The mechanical strength of the joints must not be less than 90% of the strength of the transmission line itself, and the resistors must not exceed 1.2 times the resistance of the transmission line of the same length. Jumpers are connected at tension rods, tie rods, etc., and can be connected to the connection slots via T-shaped wire trays, serving as a splitter 5. The riveting methods for overhead cables can be divided into clamp connections, hydraulic connections, and sudden connections
2. Pipeline engineering installation and construction technology
Gate valve testing
Gate valves should undergo sleeve pressure tests and sealing tests
The pressure and sealing tests of gate valve housing should use clean water as the material. The chloride ion content in the stainless steel valve test water should not exceed 25 ppm
The gate valve housing pressure test is 1.5 times the maximum allowable working pressure at 20°C, and the sealing test is 1.1 times the maximum working pressure at 20°C. The experiment duration should be no less than 5 minutes. The experimental temperature is 5-40°C; if it is less than 5°C, temperature rise measures should be taken
Gate valve calibration should be conducted according to national standards and design material requirements through setting pressure adjustment and sealing tests. The inspection of safety valves should be properly recorded, sealed, and the inspection report displayed
Conditions that should be met before pipeline system experiments
Within the testing area, the pipeline installation quality meets standards
The test plan has been approved, and safety technical disclosures have been conducted
The compensator on the line has been temporarily suppressed
The laboratory pressure gauge should be checked during weekly inspections, with an accuracy not less than 1.6. The full-scale value of the gauge should measure 1.5~2 times the working pressure, and there should be no fewer than 2 pressure gauges
According to the test plan, pipeline reinforcement, control circuit division, and component protection pipeline reinforcement were carried out. Use blind plates or other isolation measures to separate the waiting tube from unrelated systems. Gate valves, rupture plates, and dashboard assemblies have been removed or protected during the tube fertilization process
Key points for pipeline pressure testing
Under internal pressure, the experimental working pressure for seamless steel pipes and rare metal pipes should be 1.15 times the design working pressure, and for the vacuum solenoid valve channel, the experimental working pressure should be 0.2MPa
Experiments should be equipped with working pressure release devices, and the working pressure should not exceed 1.1 times the working pressure
Before the experiment, air is used for a pre-pressure test, with a working pressure of 0.2 MPa
During the experiment, the pressure should be adjusted gradually. When the working pressure rises to 50% of the experimental working pressure, if there are no abnormalities or leakage, the pressure should be changed step by step according to 10% of the experimental working pressure, and the pressure on each layer should be stabilized for 3 minutes until the experimental working pressure is reached. Under the experimental working pressure, maintain the pressure steadily for 10 minutes, then reduce it to the design working pressure. The foam adhesive has passed leakage testing and is qualified.
