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1. Adjustment of the opening pressure (set pressure): Within the specified operating pressure range, the opening pressure can be adjusted by rotating the adjustment screw, thereby changing the amount of compression of the spring. Remove the valve cover cap and loosen the lock nut, after which the adjustment screw can be adjusted. First, increase the inlet pressure to cause the valve to open once; if the opening pressure is too low, tighten the adjustment screw in a clockwise direction ； If the pressure when it is turned on is too high, loosen it in a counterclockwise direction. Once the desired opening pressure has been adjusted, tighten the lock nut and install the cover cap. If the required opening pressure exceeds the operating pressure range of the spring, it is necessary to replace it with another spring whose operating pressure range is suitable, and make adjustments accordingly. After replacing the spring, the corresponding values on the nameplate must be changed. 2. When adjusting the opening pressure, the following points should be taken into consideration: when the medium pressure approaches the opening pressure (reaching over 90% of the opening pressure), the adjustment screw should not be rotated, to prevent the valve disc from rotating as well and thus damaging the sealing surface. To ensure the accuracy of the opening pressure value, the medium conditions used for adjustment, such as the type of medium and its temperature, should be as close as possible to the actual operating conditions. The opening pressure often changes when the type of medium changes, especially when going from a liquid phase to a gas phase. As the operating temperature increases, the opening pressure decreases. Therefore, when it is adjusted at normal temperature for use at high temperatures, the set pressure value at normal temperature should be slightly higher than the opening pressure value required. 3. Adjustment of discharge pressure and return pressure: After the opening pressure has been adjusted, if the discharge pressure or return pressure does not meet the requirements, the adjustment ring on the valve seat can be used for fine-tuning. Unscrew the fixing screw of the adjustment ring, insert a tool such as a thin iron rod into the exposed screw hole, and you can move the teeth on the adjustment ring to rotate it left and right. When the adjustment ring rotates to the right in a counterclockwise direction, its position rises, and both the discharge pressure and the return pressure decrease ； Conversely, when the adjusting ring rotates clockwise to the left, its position drops, and both the discharge pressure and the return pressure increase. With each adjustment, the rotation amplitude of the adjusting ring should not be too large (generally within 5 teeth). After each adjustment, the set screw should be tightened so that its tip lies in the groove between the two teeth of the adjustment ring, in order to prevent the adjustment ring from rotating; however, no lateral pressure should be applied to the adjustment ring. Then, a movement test is conducted. For safety reasons, before turning the adjustment knob, the inlet pressure of the safety valve should be reduced appropriately (generally to below 90% of the opening pressure) to prevent the valve from opening suddenly during adjustment and causing an accident. It must be noted that conducting tests on the discharge pressure and seating pressure of safety valves is only possible when the flow rate from the gas supply is high enough to prevent the valve from opening (i.e., when the rated discharge capacity of the safety valve is reached). Moreover, the test benches commonly used to verify the opening pressure of safety valves have very limited capacity; in such cases, the valve cannot be opened fully, and its reset pressure is also inaccurate. When calibrating the opening pressure on such a test bench, in order to make the starting action more noticeable, the adjustment ring is usually set at a relatively high position; however, this is not appropriate under the actual operating conditions of the valve, and it is necessary to readjust the position of the adjustment ring. 4 Lead sealing: After all safety valves have been adjusted, they should be sealed with lead to prevent any unauthorized changes to the adjusted settings. When leaving the factory, safety valves are usually adjusted using ambient air at the upper limit of the operating pressure class (i.e., high pressure), unless otherwise specified. Therefore, users generally need to make adjustments based on the actual working conditions. Then re-seal it with lead.