The safety operating procedures for the testing device of the exhalation valve mask airtightness tester cover aspects such as pre testing preparation, testing process operation, abnormal handling, and post testing maintenance, as follows:
1、 Preparation before testing
Equipment inspection and installation
Environmental requirements: Place the tester in an area without air vents, vibrations, strong magnetic fields, and good ventilation, away from sources of fire, heat, and flammable and explosive materials.
Power and gas source:
Use a 24V safe power supply to ensure stable voltage and compliance with equipment requirements, and avoid using power sources outside of specifications to prevent electric shock or fire.
Connect a dry and impurity free gas source (pressure 0.4-0.8MPa), avoid sharing the same gas source with other pneumatic components, and prevent gas source fluctuations from affecting the test.
Connection between trachea and fixture:
Check if the gas source pipeline is securely fixed to prevent injury caused by the swinging of the gas pipe due to high-pressure gas injection.
Connect the test trachea firmly to the fixture and ensure there is no air leakage.
Molds and fixtures:
Install the test mold onto the fixture fixture, ensuring that the upper and lower molds are aligned and there are no gaps, to avoid product displacement during testing that may cause hand clamping.
Check that there are no residual fragments inside the mold to prevent foreign objects from splashing and injuring people during pressurization.
Parameter Settings
Set parameters according to testing standards (such as GB2626-2006, GB/T16556-2007), including inflation time, holding time, testing time, pressure relief time, and leakage alarm threshold.
Parameter settings should refer to the equipment manual to ensure accuracy and avoid overpressure causing the sealing ring to burst or the mold to pop open.
Product Preparation
Clean the test mask to ensure that the surface is dry, free of impurities, and without obvious damage.
Select matching fixtures based on mask specifications to ensure that the mask is securely fixed during testing.
2、 Testing process operation
Start testing
Turn on the power switch of the tester, enter the main interface, and select the testing mode (such as system airtightness test, exhalation valve airtightness test).
Wear the mask on the test head mold (or place it in the fixture), ensuring that the exhalation valve is well sealed with the testing interface.
Manually press the start button on the fixture, and the tester will automatically enter testing mode.
data monitoring
Pay close attention to pressure changes and testing progress on the display screen to ensure data stability.
During the testing process, it is prohibited to reach out and adjust the interior of the fixture. Even if the equipment is equipped with grating protection, it is necessary to wait for the cylinder to rise or for the testing to be completed before operating.
Result determination
After the test is completed, the results will be automatically determined based on the preset parameters:
Qualified: The display screen shows "PASS" and the OK light is on.
Unqualified: The display screen shows "FAIL", the NG light is on and accompanied by a buzzing sound.
Print test results (including temperature and humidity, time, product type, etc.) for easy recording and traceability.
3、 Exception handling
emergency
In case of sudden shutdown, severe leakage, or abnormal closure of the mold, immediately press the emergency stop button to cut off the power and gas supply.
Quickly evacuate the scene and report to the person in charge, taking emergency measures such as checking the gas source and troubleshooting circuit faults.
Mechanical safety
Before testing, confirm that there is no personnel intervention inside the fixture. After the test is completed, wait for the air pressure to be completely released before disassembling the product to avoid component ejection caused by residual pressure.
Do not step on, lean on, or place heavy objects on top of the equipment to prevent it from tipping over due to imbalance.
4、 Maintenance after testing
Cleaning and Maintenance
After the test is completed, clean the outer shell and internal components of the tester (such as pressure sensors and air circuits) in a timely manner to remove dust and oil stains.
Regularly replace the air source filter to prevent impurities from entering the interior of the equipment.
Calibration and Maintenance
Regularly calibrate the tester to ensure testing accuracy.
Check the sensitivity of the pressure sensor, and replace it promptly if performance degradation or damage is found.
data management
Record the test results in detail, including testing time, parameters, results, etc.
Identify and isolate non-conforming products to prevent them from flowing into the next process.
5、 Safety precautions
Personal protection: Wear cut resistant gloves and protective goggles during operation to avoid splashing or mechanical injury.
Prohibited behavior:
Do not use the equipment in damp, direct sunlight, high temperature or extremely cold environments.
Unauthorized disassembly of equipment or modification of circuits is prohibited to prevent electric shock or instrument damage.
Long term disuse: If the equipment is not used for a long time, the power and gas sources should be cut off to ensure safety.