Have to look at the little knowledge of the valve before reading are found to be wrong!

Newly designed and installed control system, in order to ensure that the regulating valve can work normally while driving and make the system run safely, the new valve should be checked whether the nameplate mark on the valve accords with the design requirement before installation. The following items should also be debugged. Basic error limit; full stroke deviation; backlash; dead zone; leakage (in demanding occasions). If the original system is overhauled control valve, in addition to the above-mentioned verification, but also the old valve should be stuffing box and connections and other parts of a tightness check.

1, blue seal and leak seal treatment methods

The factors that affect the seal of the flange are many. Mainly: bolt preload; sealing surface type; gasket performance; flange stiffness; operating conditions. For decades, ANSI Flanges designed by the National Institute of Standards have provided a proven seal technology for the oil and gas industry and have been very successful. However, as the needs of the oil and gas industry have changed, defects in ANSI flanges continue to emerge. The principles of cost-effectiveness, environmental protection, and best health and safety assurance are faced by operators and contractors in the 21st century

2, stainless steel butterfly valve corrosion reasons

Stainless steel butterfly valve rust phenomenon occurs during use. After metallographic analysis, dyeing test face, heat treatment test face, SEM and other test analysis, we found that the key factor of material corrosion is carbide precipitation along the grain boundary in the material to form a chromium-depleted zone, resulting in stainless steel butterfly valve corrosion. Material stainless steel butterfly valve CF8M corroded during use. Austenitic stainless steel after normal heat treatment, the organization should be austenitic at room temperature, corrosion resistance is very good. In order to analyze the cause of corrosion of the butterfly valve, samples were taken for analysis.

Pneumatic control valve is the compressed air as the power source to the cylinder as the actuator, and with the help of electrical valve positioners, converters, solenoid valves, retention valves and other accessories to drive the valve to achieve the switch or the proportion of regulation, the receiving industry Automatic control system to complete the control signal to adjust the pipeline media flow, pressure, temperature and other process parameters. Pneumatic control valve is characterized by simple control, rapid response, and intrinsically safe, without additional measures taken to prevent explosion.

Valve seal and performance

1. Valve assembly must be completed after the performance test to check whether the product meets the design requirements and whether the quality standards set by the state. Valve materials, rough, heat treatment, machining and assembly defects are generally exposed during the test. Conventional tests have shell strength test, seal test, low pressure seal test, action test, etc., and according to need, according to the order of one by one test after the next test.

2. Strength test: the valve can be seen as a pressure vessel, it must meet the pressure without the media to withstand the requirements, so the valve body, valve cover and other parts of the blank should not affect the intensity of cracks, loose pores, slag Other defects. Valve manufacturer in addition to rough appearance and internal quality of the rigorous testing, but also by the intensity of each test to ensure that the valve performance.

3, butterfly valve test and installation and troubleshooting

Butterfly valve either manually, pneumatic, hydraulic, electric components are strictly debug before leaving the factory, the user re-sealant performance, the import and export should be evenly fixed on both sides, close the butterfly valve, the pressure on the inlet side, at the exit Side of the leak to observe the phenomenon, the pipe strength test, the plate should be opened to prevent damage to the seal pair.

Although the products are strictly inspected and tested before leaving the factory, there are some problems that the screw displacement of individual products should be adjusted during the transportation. To readjust, pneumatic, hydraulic and so on, please read the instruction manual of the drive unit.

Electric drive disc valve factory control mechanism has been Kai, closed stroke adjusted. To prevent the power is turned on the wrong direction, the user first turn on the power, the first open manually to the semi-open position, press the electric switch to check the direction of the disc and valve closing direction can be consistent.

4, the pressure relief valve leakage reasons

Pressure reducing valve as an important component of hydraulic system, its main role is to make the system outlet pressure is always lower than the inlet pressure level to maintain the system outlet pressure stability, and the system outlet pressure from inlet pressure and flow fluctuations ; However, once the valve sealing surface leakage occurs, not only affect the normal production, but also cause the loss of hydraulic oil, polluting the environment; in the marine hydraulic system, the valve as the main control element, the importance of its sealing is not to be underestimated of. After a joint study with relevant experts and found that the pressure relief valve between the sleeve and the valve body seal is mainly relying on the connection between the sleeve and the inner wall of the O-ring between the circumferential seal, the seal once effective, the outside Leaks are inevitable.