Simple installation method for gas blind flange valves in chemical plants—blind flange valves

　　1. Before installation, be sure to conduct a visual inspection. For valves with a working pressure exceeding 1.0 MPa and those installed on main pipelines with shut-off functions, perform strength and tightness tests prior to installation. Only after passing these tests are they permitted for use.

　　2. When installing a check valve for nearsightedness glasses, attention should be paid to the direction of fluid flow. The actual flow direction of the fluid must match the direction indicated by the arrow symbol on the oil circuit board; otherwise, the normal flow of the fluid will be disrupted. The bottom valve of the water pump should be installed at the bottom of the suction pipe of the centrifugal pump.

　　3. When the shut-off valve of a pair of myopia glasses is closed, it can generate water hammer pressure in the pipeline, which, in severe cases, may damage the gate valve, pipeline, or equipment—especially in small-diameter or high-pressure pipelines. Therefore, users of check valves should pay close attention.

　　4. When the upper and lower valves become loose, the substance may leak outward. To ensure safety, before shutting down, first close the liquefied gas disc valve located upstream of the blind flange valve. Additionally, please implement natural ventilation and other safety measures to guarantee operational safety.

　　5. The silicone sealing ring must not be allowed to stick to or rub against the oil circuit board, in order to avoid damaging the silicone sealing ring and compromising the operational characteristics of the valve.

　　6. During the entire opening and closing process of the gate valve, the pipeline should also be capable of accommodating elastic deformation or displacement due to the aforementioned offsets. It is recommended to install it as follows:

　　Simple Installation Method for Natural Gas Blind Flange Valves in Chemical Plants: Installation and Maintenance Procedures for Blind Flange Valves are as follows:

　　a. Before installation, carefully check whether the valve’s model, specification, applicable medium, and operating temperature are consistent with those of the pipeline system.

　　b. The arrow marking on the gate valve must align with the flow direction of the substance in the pipeline; be sure not to install it backward.

　　c. The gate valve can be installed as long as it remains clean and undamaged throughout the transportation process.

　　d. When operating manually, turning clockwise closes the valve, while turning in the opposite direction opens it. During operation, pay attention to the second hand or the inner-diameter gauge indicator.

　　e. When wiring the electrical components, first verify that the phase sequence is correct before proceeding with installation. After wiring, carefully adjust using the “Start Light-Up” method and notify our company in advance.

　　f. After the electrical wiring of the gate valve is completed, first manually open the valve to a halfway-closed position, then connect the power supply. Use the actuator to adjust the valve until the power switch indicates accurately, confirming that the travel control and torque control are functioning properly. Only after this verification can the valve be officially put into service. This precaution is essential to prevent serious damage to the gate valve—and potential major safety incidents—caused by incorrect connections of the power supply, neutral wire, and live wire, which could result in the valve’s on/off signals being inconsistent with its actual on/off positions. After installation, when conducting pressure hydrostatic tests on the system or piping, the gate valve must be fully opened.

　　g. Both welded flanges and socket-weld flange assemblies can be used. If the temperature of the medium in the pipeline exceeds 100°C, a burn-warning tag should be affixed to the valve. During the opening and closing of the blind flange valve, if there is external leakage of the medium, it is recommended to install a butterfly valve or other pressure-relief device upstream of this valve to minimize external leakage during the valve’s operation. When installing the blind flange valve, its base and anchor bolts must be securely fastened to a steel-frame platform or a concrete foundation. The blind flange valve is pre-adjusted at the factory; before use, manually operate the valve to position it in the middle (neutral) position. Then, connect the power supply and start the actuator, observing carefully whether the valve’s loosening and clamping directions are consistent with those indicated on the valve itself.

　　h. Before adjustment, be sure to loosen the three anchor bolts around the expansion joint to ensure the expansion joint’s expansion and contraction range.