During the completion of the project, the following requirements must be met:

1. Requirements for earthquake resistance:
It must be able to resist an earthquake with an intensity of 6 degrees, and the system design shall refer to GB/T 50761-2018 Code for Seismic Design of Petrochemical Steel Equipment.

2. Welding:
The inner wall of storage tank and chromatography column must be polished by mechanical polishing, so as not to affect the quality of pickling and passivation of stainless steel lining. The welding of the pipeline all adopts the non-solder argon protection automatic welding technology, the solder needle needs to choose lanthanum tungsten needle, the solder joint needs to be smooth and flat. Stainless steel pipe welding seams need to be smooth and flat, without unevenness, and meet the sanitary pipe welding acceptance standard ASME BPE-2016. The welding discoloration level meets the welding discoloration level of the inner surface of the austenitic stainless steel pipe of the raw pipe welding acceptance standard AWS D18.2, and is no worse than the discoloration level of Figure 3, as shown in Figure 9. The protective argon used for welding needs to reach a purity of 5 9 and above.

3. Cleaning (cleanliness):
All stainless steel surfaces in contact with liquid must be degreased and precisely cleaned. The specific cleaning requirements are as follows:
a) Alumina adsorption column, 10m3 storage tank and 5m3 storage tank and pipeline shall be pickled and passivated.
B) The interior of 10m3 storage tank and 5m3 storage tank shall be mechanically polished to meet the requirement of roughness ≤ 0.4um.
c) All pipelines are electrolytic polishing pipes, which shall be cleaned to remove the welding oxidation color on the inner wall and be passivated.

The inner surfaces of valves, instruments, pump heads and other parts need to be pickled and passivated accordingly. All those that can be disassembled and washed need to be disassembled and cleaned separately, while those that cannot be disassembled need to be washed in series.

The quality standards and inspection methods for cleaning acceptance are as follows, which need to be strictly implemented in the corresponding steps of the cleaning process:
1) Appearance inspection: After the cleaning is completed, the surface of the workpiece shall be visually inspected under the illumination of ≥ 500 lux (equivalent to the brightness of 30cm from the 100W bulb): the surface must be free of debris, dust, grease deposits, welding or spraying foreign matter. The surface of pickling passivation shall be uniform silvery white without obvious corrosion traces. The surface of weld and heat affected zone shall be free of oxidation color and uneven color spots.
2) white cloth detection: after cleaning is completed, use 1000 grade clean room special ultra-fine dust-free white cloth to wipe the surface of the workpiece, visual inspection without any visible discoloration and particles.
3) resistivity detection: cycle cleaning process, washing water cleanliness detection method. The final precision cleaning requires the use of high-purity deionized water, the use of resistivity meter for detection, circulation cleaning circuit inlet and outlet water resistivity difference ≤ 4MΩ.
4) Blue dot detection method of stainless steel passivation film (sampling inspection or stainless steel test piece detection): The blue dot detection solution is coated on the cleaned and passivated stainless steel surface, and the passivation is qualified if there is no blue dot within 30 seconds.
5) Endoscopic inspection (TV inspection): After the cleaning is completed, an endoscope shall be used to carry out quality inspection on the welding spots on the inner wall of stainless steel. The inspection results shall be free of any visible welding oxidation color, rust spots and other pollution. Party B shall provide necessary video or photo records.
6)PH residual liquid inspection: use acidometer or phenolphthalein PH extensive test paper to check the washing degree of pickling passivation liquid residual liquid on the surface of the workpiece, and the neutral PH value (6~8) is qualified.
7) Purple (black) light detection: use purple light to check the surface, check whether the stainless steel surface degreasing is complete, the inspection results are not allowed to appear fluorescence (blue and white bright spots or yellow and green bright spots).
8) Surface finish detection: Use a surface roughness meter to compare and measure the surface finish of stainless steel before and after pickling and passivation cleaning to ensure that the surface finish of stainless steel is not broken after pickling and is always kept at Ra≤ 0.4um.
9) Detection of particulate matter in water: Party B shall take samples and Party A shall detect them. The specific inspection method shall be determined after confirmation with relevant personnel of Party A. The suspended particles in the sample shall reach the standard Level 50 of the high energy cleaning institute, as shown in the figure.

10) Absorption spectrum detection: detection after cleaning. Party A shall use a UV-Vis spectrophotometer to detect the cleanliness of the cleaning water sample, and the sample test results shall be consistent with the comparison sample.

4. Leakage rate (tightness):
1) The overall system pipeline, vacuum helium leak detection, the overall leakage rate of the pipeline must not be greater than 10^-6mbarl/s。
2) For vacuum helium leak detection of chromatography columns and storage tanks, the single overall leak rate must not be greater than 10^-7mbarl/s。
3) For vacuum helium leak detection of connectors and double O-ring flanges, the single overall leak rate must not be greater than 10^-7mbarl/s。

5. Partial results of site acceptance

Purification system outlet water sample particle detection structure raw data