Practical Exercise on Purification Technology Version [006]

1. It is necessary to ensure that the pressure gauge to be replaced has an appropriate range compared to the original gauge. 2. The primary valve of the pressure gauge must be closed to ensure isolation from the system, and the pressure must be released. 3. After replacing the pressure gauge, slowly open the valve once to check for any leaks.

1. Check whether the spare pressure gauge is in good condition. 2. Verify that the performance and range of the spare pressure gauge meet the requirements. 3. Close the isolation valve at the base of the pressure gauge and remove the existing one. 4. Install the spare pressure gauge, ensuring its front face is in a position where it can be easily observed. 5. Open the valve at the base of the pressure gauge, check for any leaks, and verify that the pressure is normal. 6. Collect the old pressure gauge.

1. Check whether the spare pressure gauge is in good condition. 2. Verify that the performance and range of the spare pressure gauge meet the requirements. 3. Close the isolation valve at the base of the pressure gauge and remove the gauge that needs to be replaced. 4. Install the spare pressure gauge, ensuring its front face is in a position where it can be easily observed. 5. Open the root valve of the pressure gauge to check for leaks and whether the pressure is normal. 6. Recycle the removed pressure gauge.

1. Check whether the spare pressure gauge is in good condition. 2. Verify that the performance and range of the spare pressure gauge meet the requirements. 3. Close the isolation valve at the base of the pressure gauge and remove the existing pressure gauge. 4. Install the spare pressure gauge, ensuring its front face is in a position where it can be easily observed. 5. Open the valve at the base of the pressure gauge, check for any leaks, and verify that the pressure is normal. 6. Collect the old pressure gauge

1. Inspection: a) Check the process, record the pressure value, and ensure that the eye, pointer, and scale are aligned in a straight line perpendicular to the dial when observing the pressure. 　　b) Check whether the range of the pressure gauge under inspection is the same as that of a qualified pressure gauge. 　　2. Remove the pressure gauge 　　　a) Close the pressure gauge shut-off valve. 　　b) Hold a adjustable wrench in each hand, apply the wrench at the gauge connection, loosen the pressure gauge, and while doing so shake the gauge to release any remaining pressure. Once the gauge pointer returns to zero, put down the wrench in your hand, grasp the gauge connector with your hand to remove the gauge and place it in an appropriate location. Use a screwdriver to clean any dirt inside the gauge connector, and then wipe it clean with a piece of fine cloth. 　　3. Install the pressure gauge 　　4. Pressure test

1. Inspection: a) Check the process, record the pressure value, and ensure that the eye, pointer, and scale are aligned in a straight line perpendicular to the dial when observing the pressure. 　　b) Check whether the range of the pressure gauge under inspection is the same as that of a qualified pressure gauge. 　　2. Remove the pressure gauge: a) Close the pressure gauge shut-off valve. 　　b) Hold a adjustable wrench in each hand, apply the wrench at the gauge connection, loosen the pressure gauge, and while doing so shake the gauge to release any remaining pressure. Once the gauge pointer returns to zero, put down the wrench in your hand, grasp the gauge connector with your hand to remove the gauge and place it in an appropriate location. Use a screwdriver to clean any dirt inside the gauge connector, and then wipe it clean with a piece of fine cloth. 　　3. Install the pressure gauge: Wrap an appropriate amount of tape around the threads of the qualified pressure gauge in a clockwise direction, align the pressure gauge with the connector, turn it on slowly; after ensuring that it is not misaligned after a few turns, tighten it further using two adjustable wrenches. 　　4. Pressure testing: After installing the pressure gauge, slowly open its shut-off valve. Stop when the gauge pointer indicates pressure; once the pressure stops rising, carefully check for any leaks at the connections of the gauge. Once everything is confirmed to be fine, open the shut-off valve fully. 　　5. Compare pressure values: a) Record the pressure shown on the pressure gauge; when observing the pressure, ensure that the eyes, pointer, and scale are aligned in a straight line perpendicular to the dial. 　　b) Compare the pressure values of the two gauges; if the difference is not greater than the allowable error of the gauge – that is, the product of the gauge’s maximum range and the percentage corresponding to its accuracy class – then the original gauge can be used weiterhin. If the difference is greater than the allowable error of the pressure gauge, then the gauge cannot be used any longer.

1. Inspection: a) Check the process, record the pressure value, and ensure that the eye, pointer, and scale are aligned in a straight line perpendicular to the dial when observing the pressure. 　　b) Check whether the range of the pressure gauge under inspection is the same as that of a qualified pressure gauge. 　　2. Remove the pressure gauge: a) Close the pressure gauge shut-off valve. 　　b) Hold a adjustable wrench in each hand, apply the wrench at the gauge connection, loosen the pressure gauge, and while doing so shake the gauge to release any remaining pressure. Once the gauge pointer returns to zero, put down the wrench in your hand, grasp the gauge connector with your hand to remove the gauge and place it in an appropriate location. Use a screwdriver to clean any dirt inside the gauge connector, and then wipe it clean with a piece of fine cloth. 　　3. Install the pressure gauge: Wrap an appropriate amount of tape around the threads of the qualified pressure gauge in a clockwise direction, align the pressure gauge with the connector, turn it on slowly; after ensuring that it is not misaligned after a few turns, tighten it further using two adjustable wrenches. 　　4. Pressure testing:

1. Inspection: a) Check the process, record the pressure value, and ensure that the eye, pointer, and scale are aligned in a straight line perpendicular to the dial when observing the pressure. 　　b) Check whether the range of the pressure gauge under inspection is the same as that of a qualified pressure gauge. 　　2. Remove the pressure gauge: a) Close the pressure gauge shut-off valve. 　　b) Hold a adjustable wrench in each hand, apply the wrench at the gauge connection, loosen the pressure gauge, and while doing so shake the gauge to release any remaining pressure. Once the gauge pointer returns to zero, put down the wrench in your hand, grasp the gauge connector with your hand to remove the gauge and place it in an appropriate location. Use a screwdriver to clean any dirt inside the gauge connector, and then wipe it clean with a piece of fine cloth. 　　3. Install the pressure gauge: Wrap an appropriate amount of tape around the threads of the qualified pressure gauge in a clockwise direction, align the pressure gauge with the connector, turn it on slowly; after ensuring that it is not misaligned after a few turns, tighten it further using two adjustable wrenches. 　　4. Pressure testing:

Close the root valve, loosen it slightly, and release pressure slowly. Once it is confirmed that there is no pressure left, remove the pressure gauge, install a new one, and then slowly open the root valve.