HG/T 2387-1992 Quality Standard for Chemical Cleaning of Industrial Equipment
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T 2387—92
Quality Standard for Chemical Cleaning of Industrial Equipment
Published on September 15, 1992
Ministry of Chemical Industry of the People's Republic of China
Implementation on July 1, 1993
Chemical Industry Standard of the People's Republic of China
Quality Standard for Chemical Cleaning of Industrial Equipment
1 Subject Content and Scope of Application
This standard specifies the technical requirements, quality indicators and test methods for chemical cleaning of industrial equipment. HG/T2387—92
This standard applies to the cleaning of scale, rust, oil and other dirt on industrial equipment made of iron, steel, aluminum and their alloys. Chemical cleaning: Chemical cleaning of industrial equipment material scale and chemical cleaning of industrial equipment scale made of other materials can also be referred to. 2 Reference standards
GB8923 Surface rust grade and rust removal grade of steel before painting HG5-1526 Technical conditions for standard corrosion test pieces for chemical treatment of cooling water HGJ202 Construction and acceptance specifications for degreasing projects SD-135 Chemical cleaning rules for boilers in thermal power plants 3 Special numbers, codes, and terms
3.1 Chemical cleaning: It is a method of using chemical agents and their aqueous solutions to clean equipment scale. 3.2K——Corrosion rate, /(m2.h).
3.3A——Corrosion amount, g/m. During the chemical cleaning process, the amount of material reduced per unit area of the standard corrosion test piece. 3.4N—Descaling rate, %, the percentage of the scale removed from the scale pan to the original scale before cleaning, 3.5Day—Cleaning rate, %, the surface of the cleaning equipment originally covered by dirt, the percentage of the area of dirt removed after chemical cleaning to the original short cover area before cleaning
3.6 Monitoring pipe: During the chemical cleaning construction, a section of pipe is used to monitor the progress of the cleaning process and to determine the descaling rate. This section of pipe can be made from the cleaned equipment, and the dirt attached to it should be able to represent the scaling characteristics of the equipment. 3.7 Designated surface: A part of the visible surface of the equipment cleaning surface jointly designated by the user and the construction party before cleaning, used to determine the cleaning rate, and the dirt attached to it should be able to represent the scaling characteristics of the equipment, 3.8 Undesignated surface: The visible cleaning surface other than the designated surface of the equipment. 4 Technical requirements
In the formulation of construction plans and on-site construction, chemical decontamination projects should comply with this standard in addition to the relevant technical conditions or specifications of the equipment and other technical requirements agreed upon by the user and the construction party, such as: HGJ202, SD-135 and the "Low-E Boiler Chemical Full Washing Rules" issued by the Ministry of Labor, etc.
4,1 Before chemical cleaning, the parts and other accessories that can be damaged by the cleaning liquid and affect normal operation should be removed or isolated. Those that cannot be removed or isolated should not cause damage due to cleaning. 4.2 After chemical full washing, the harmful residual liquid and residue in the equipment should be cleaned up and should meet the corresponding standards. 4.3 The cleaned surface of the equipment should be free of secondary floating rust, ruthless metal replacement precipitation, and over-washing without metal coarse crystal precipitation, and a complete passivation film should be formed.
4.4 The liquid in the chemical cleaning process is not allowed to be discharged directly into natural water bodies, but should be discharged into the local sewage treatment system nearby and centrally treated. Approved by the Ministry of Chemical Industry of the People's Republic of China on September 15, 1992 and implemented on July 1, 1993
, and discharged in compliance with the standards.
Quality indicators of chemical cleaning
5.1 Corrosion rate and corrosion amount
HG/ T 2387 --92
In the chemical cleaning process, the corrosion rate and corrosion amount of the equipment structure materials must be controlled for any pickling process, and the indicators should not be greater than those in Table 1 Regulations,
Table 1 Corrosion rate and corrosion index
Equipment materials
Iron and iron alloys
Copper and copper alloys
Aluminum and aluminum alloys
5.2 Descaling rate and cleaning rate
Corrosion rate
The descaling rate and cleaning rate of the equipment after chemical cleaning shall not be less than the regulations in Table 2. Table 2 Descaling rate and cleaning rate index
Equipment materials
Carbonate scale
Non-carbonate scale
Other scale types
6 Test method
6.1 Determination of corrosion rate and corrosion amount
Agreed by both parties
Agreed by both parties
6.1.1 Take at least 3 standard corrosion test pieces that meet the requirements of HG5-1526 and test them according to HG 5-1526 Article 3: After treatment, weigh them with an analytical balance with a precision of 1/10,000. Then, place them in the designated position in the cleaning system, take them out after cleaning, and weigh them again. 6.1.2 Substitute the measured and known data into formula (1) and formula (2) to calculate the corrosion rate and corrosion amount W.-W,
Where: K——Corrosion rate, g/(m*.h); A
——Corrosion amount, g/m2;
Wi——Mass of corrosion test piece before decontamination and cleaning, 8:Mass of corrosion test piece after cleaning, g;
HG/T2387---92
FStandard corrosion test piece surface area, m*;
Cleaning time. h.
Note: The calculation method of cleaning time is that the time interval from the beginning of adding pickling liquid to the end of draining the pickling liquid is the washing time. 61.3 The magic fairy rate and brain corrosion amount of each standard corrosion test piece are calculated by arithmetic average method as the corrosion rate of metal materials and magic corrosion G2 descaling rate.
In 2.1, the volume VV of the monitoring tube before and after cleaning is accurately measured with distilled water and a drum. According to the known inner diameter D of the monitoring tube (or measured with a vernier caliper), the volume Vo of the scale-free monitoring tube is calculated according to formula (3), and then the descaling rate is calculated by formula (4). 3.14
Where: N—descaling rate, %;
V—--volume of the scale-free monitoring tube, InL;
D—inner diameter of the scale-free monitoring tube, mm;
H——length of the monitoring tube, am
V, volume of the monitoring tube before cleaning, mL;
V——volume of the monitoring tube after cleaning, mL.
×100%
2.2 Repeat the above method for measurement three times, and use the arithmetic average method to calculate the descaling rate obtained each time as the descaling rate. 6.3 Determination of cleaning rate
right.3.1 When the designated surface is determined, the area of the dirt-covered surface So is obtained. After the drip washing is completed, use rectangular coordinate paper and carbon paper to print the residual dirt area on the designated surface to obtain S. Calculate the cleaning rate according to formula (5), B
Where: B Cleaning rate, %;
× 100%
S. =The area covered by dirt on the designated surface before cleaning, m; S,——The area covered by dirt on the designated surface after cleaning, m.63.2 Repeat the above method three times, and use the arithmetic average method to calculate the cleaning rate obtained each time as the cleaning rate. 6.4 Determination of oil dirt
6.4.1 Test method
Use filter paper or white wipes to wipe back and forth on the cleaned surface of the equipment or monitoring tube, designated surface, undesignated surface, etc., and then use visual inspection to evaluate the cleanliness of the test object after the test. 6.4.2 Ultraviolet light or black light method
Put the cleaned surface of the equipment or monitoring tube, designated surface, undesignated surface, etc. to be inspected in a dark place, and use a special ultraviolet lamp or light lamp with a wavelength of 320~380nm to irradiate the inspection surface. 6.4.3 Water hanging method
. Inspection of monitoring tube
HG/T2387—92
Put the degreased monitoring tube into a water tank filled with distilled water and immerse it. Then lift the monitoring tube out of the water and make it plumb about 106. Observe the water film coverage. The area covered by the water film indicates that it is clean. The area without the water film indicates that there is oil. b. Inspection of the designated surface (the designated surface should be plumb at this time). Use a small, clean and impurity-free sprayer to spray distilled water on the plumb designated surface and make the water film uniform. After about 10 seconds, observe the water film coverage.
7 Inspection specification for chemical washing disk
7.1 Inspection of corrosion rate and corrosion amount
Determination of corrosion rate and corrosion disk, see 6.1; 8.
b. Observe the surface of the standard corrosion test piece by visual inspection. It is qualified if there is no local corrosion. 7.2 Inspection of scale removal rate and cleaning rate
Tools. Determination of descaling rate, method see Article 6.2; b. Determination of cleaning rate, method see Article 6.3; Determine the descaling rate and cleaning rate of unspecified surfaces by self-test; d. When b cannot be implemented, the parties shall agree on 7.3 Inspection of rust descaling rate and cleaning rate
7.3.1 When rust must be completely removed, the equipment or monitoring pipe, designated surface or unspecified surface to be cleaned, etc., must be inspected in accordance with the provisions of GB8923
7.4 Inspection of oil descaling rate and cleaning rate
7.4.1 The oil stains on the equipment that is directly or possibly in contact with oxygen, oxygen-rich, concentrated phosphoric acid and other strong oxidizing media must be thoroughly removed. Any of the following inspection methods can be used:
Check the monitoring tube (or designated surface) and the undesignated surface of the equipment by the wiping method (see Article 6.4.I), and visually confirm that there is no oil stain on the filter paper a.
or white wiping test object,
b Irradiate the monitoring tube (or designated surface) and the undesignated surface of the equipment with ultraviolet light or black light method (see Article 6.4.2), and visually confirm that there is no purple-blue fluorescence or any stain on the cleaned surface, 7.4.2 When there is no special requirement for removing oil stains, check the monitoring tube (or designated surface) by the water hanging method (see Article 6.4.3), and visually confirm the descaling rate (or cleaning rate).
8 Acceptance of chemical cleaning project
8.1 During the acceptance of chemical cleaning project, the construction party shall submit to the user: equipment chemical cleaning plan. Construction records and various analytical test data.
&.2 The quality inspectors of the construction party and the user party shall jointly inspect the chemical cleaning quality of the equipment and fill in the results in the common inspection result column of the "Equipment Chemical Cleaning Project Quality Assessment and Acceptance Form" (see Appendix A Reference). Cleaning quality:, in accordance with the provisions of this standard, both parties can learn and hand over the work in the form
83 After the construction party completes the "Equipment Chemical Cleaning Project Construction Summary", the above documents shall be stored in the technical files by both parties. User:
Name and main material of the cleaning object:
Dirt composition and coverage:
State of the cleaning object before cleaning:
Quality inspection requirements:
Brief description of the construction process:
Inspection items
Corrosion rate
Corrosion amount
Descaling rate
Cleaning rate
HG / T 2387 —92
Appendix A
Quality Assessment and Acceptance Form for Equipment Chemical Cleaning Project (reference)
Constructor:
The project was jointly inspected and assessed by both parties on
day, and confirmed to be in compliance with the provisions of the Quality Standard for Chemical Cleaning of Industrial Equipment and other quality requirements agreed upon by both parties. The project was agreed to be handed over for acceptance. Other comments:
User:
(official seal)
Representative name:www.bzxz.net
Additional notes:
Year/Month/Day
This standard was proposed by China National Chemical Equipment Corporation. Construction party:
(official seal)
Representative signature:
This standard is under the jurisdiction of the technical management unit for standardization of chemical machinery and equipment of the Ministry of Chemical Industry. This standard was drafted by Bluestar Chemical Cleaning Group Co., Ltd., and the Chemical Machinery Research Institute of the Ministry of Chemical Industry participated in the drafting. The main drafters of this standard are Ma Qi, Lu Shaohua, Chen Hong, Han Taiwan and Wang Dongying, and the editors of Chemical Industry Standard of the People's Republic of China (Chemical Industry Standard Promotion and Research Institute of the Ministry of Chemical Industry) are from the Chemical Industry Standard Editorial Department (Chemical Industry Standard Promotion and Research Institute of the Ministry of Chemical Industry). Postal code: 100013. Printing Institute of Standardization of the Ministry of Chemical Industry. Copyright reserved. No reproduction allowed. Format: 880×12301/16. Number of shares: 10000. First edition in July 1993. First printing in July 1993. Number of copies: 1 - 1 000. Cost: 1.10 yuan. 161857
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