Clean parts must be kept sealed for installation.Requirements for the installation process are as follows: 1. The installation workshop must be clean, or a temporary clean area should be built, such as newly purchased color strips or plastic film, to prevent dust from entering during the installation process. 2, assembly workers must wear clean cotton work clothes, the head wear a pure cotton cap, hair can not leak, feet wear clean shoes, hands wear plastic gloves, fat,. 3. Assembly tools must be degreased before assembly to ensure cleanliness.   Other requirements 1. The assembled valve shall be purged with nitrogen for at least 1 minute. 2. The air tightness test must be conducted with pure nitrogen. 3. After passing the air-tightness test, the packing shall be sealed with a clean polyethylene cap. The polyethylene cap shall be soaked with organic solvent and wiped clean before use. 4. Then seal with a vacuum bag. 5. Final packing. 6. During transportation, measures should be taken to ensure that the package is not damaged.