Valve degreasing method

01PART Cleaning Steps

The components of the valve must undergo the following processes before assembly:
1. According to the processing requirements, some parts need to be polished, and the surface must not have processing burrs;
2. All parts are degreased;
3. After the degreasing is completed, pickling and passivation is carried out, and the cleaning agent does not contain phosphorus;
4. Rinse with pure water after pickling and passivation, and there should be no chemical residue, and this step is omitted for carbon steel parts;
5. Dry the parts with non-woven fabrics one by one, and do not leave the surface of the parts such as wire hair, or dry them with clean nitrogen;
6. Wipe the parts one by one with non-woven fabric or precision filter paper dipped in analytical pure alcohol until there is no dirty color.

02PART Assembly Requirements
Cleaned parts must be kept sealed for installation. The requirements for the installation process are as follows:
1. The installation workshop must be kept clean, or a temporary clean area should be built, such as using newly purchased color strips or plastic films to prevent dust from entering during the installation process.
2. Assembly workers must wear clean cotton work clothes, cotton caps, no hair leakage, clean shoes, plastic gloves, and degreased hands.
3. Assembly tools must be degreased and cleaned before assembly to ensure cleanliness

03PART other requirements
1. Purge the assembled valve with nitrogen for at least 1 minute.
2. The air tightness test must be performed with pure nitrogen.
3. Encapsulate after passing the air tightness test, and seal with a clean polyethylene cap. The polyethylene cap should be soaked in organic solvent and wiped clean before use.
4. Then seal it with a vacuum bag.
5. Final packing.
6. Measures should be taken to ensure that the package is not damaged during transportation.

04PART acceptance requirements
Acceptance follows HG 20202-2000 “Degreasing Engineering Construction and Acceptance Specifications”. Before assembly, each component is wiped with clean precision filter paper, and the dead corners of the components are selected. If the filter paper does not change color, it is qualified.