Test Conditions:
1. Fix the rim on the special jig;
2. Apply a force of 1kg/2kg/3kg to the valve, record the corresponding deformation and calculate the corresponding rigidity;
3. Take 2 times of different force to get the average value of rigidity as the final rigidity value.
Judgment Criteria:
Rigidity value ≥10N/mm (temporarily used for date collection, not for test judgment)
