2.2 equipment, machines and tools} chemical cleaning shall determine the resource allocation of temporary facilities of equipment, machines and tools according to the project quantities and the number of systems.
2.3.5 carry out special training on fluorescent flaw detector for operators participating in cleaning, and enable all operators to master the use and maintenance methods of the instrument and the inspection standard of cleaning degree.
See appendix-1 for chemical cleaning items and drugs.
The dosage shall be prepared according to 3% of the volume of the circulating cleaning system and the dispensing tank.
2.3 technical preparation before cleaning when the design document provides the cleaning scope of the device but does not provide the cleaning process, the construction team shall organize technicians to prepare the cleaning scheme and draw the cleaning flow chart of each circuit.
B) specification: 8M × 2.2m – C) main facilities in pump shed: – fb80 × Two 100 acid resistant pumps, (4) × two × 1.2m) one 9.6m3 semi enclosed water tank; One switchboard and one tool cabinet respectively.
2.1.5 triethanolamine, thiourea derivatives, washing powder and metal detergent are auxiliary chemicals and necessary materials for chemical cleaning, and their use shall be reasonably controlled in the washing process.
2.4.2 during cleaning, one fitter and one electrician shall be provided to ensure pump maintenance, electrical maintenance and normal operation of pump.
General construction process for chemical cleaning of industrial pipelines 1 scope of application this process is applicable to the chemical cleaning of pipelines such as petrochemical units and air separation units.
2.3.2 in principle, 0.5km ~ 2km is the primary circuit for the determination of cleaning circuit.
2.5 the layout of temporary facilities shall conform to the plane layout plan of the construction organization design of the plant; 2.5.2 completion of vertical works of the device.
The pipeline valves and instruments must be coordinated by the instrument workers in the cleaning process.
2.5.3 in the downstream of the dominant wind direction in the appropriate season, the cleaning workstation shall be arranged at the shortcut station of each cleaning circuit..
2.4.1 in order to ensure the continuity of the cleaning process, the cleaning personnel shall be on duty for 24 hours.
It has low acidity, edible, safe and reliable use.
2.2.2 the tools used for bubble invasion method and scrubbing method are plastic barrel, basin, stainless steel brush, brush and necessary labor protection articles.
2.1.4 sodium nitrite (or sodium phosphite) white powder, as the main agent in the passivation process during circulating cleaning, shall be prepared according to 1.2% of the volume capacity of circulating solution, and the operating temperature should be controlled at 65 ℃ ~ 70 ℃.
See Appendix 2 for the simple process of acid circulation cleaning.
In the circulating cleaning, its dosage should be prepared according to 3% of the solution volume, and better derusting effect can be obtained under the operating conditions of solution temperature above 65 ℃.
2.4.3 for the instrument pipeline of the chemical cleaning pipeline system, in principle, the process pipeline and instrument pipeline shall be cleaned separately.
— the piping between the water tank and the delivery pump can be made of stainless steel, and permanent temperature and pressure measuring points are set in the pipe network.
2.4 the labor organization} depends on the number of cleaning circuits, that is, the quantities of pipeline and equipment cleaning.
The two pump sheds are equipped with detachable circulating pipe network for transportation and free assembly.
2.1.2 citric acid (h3c6o7h2o), white silty sand, is the main raw material for rust removal and cleaning of carbon steel equipment and pipelines.
2.3.4 the construction team leader shall organize and the constructors shall make technical disclosure to the team leader, post leader and all personnel involved in chemical cleaning, focusing on the technical requirements, quality control and finished product protection in the cleaning process.
It is also suitable for chemical cleaning of equipment and instrument pressure piping in similar devices.
Fixing Socket Cross Pin Nail Plate
In principle, one set of chemical cleaning workstation shall be equipped when the pipeline cleaning quantity is less than 3km, and two sets of chemical cleaning workstations shall be equipped when the pipeline cleaning quantity is less than 3km.
E) chemical cleaning workstation can be used for water filling of storage tank, pressure test of equipment and pipeline in installation project.
It is advisable to add 0.3% surfactant at the operating temperature above 70 ℃ to obtain a better degreasing cleaning effect.
D) a set of workstation is composed of two pump sheds, one for alkali washing and one for acid pickling.
2.1.3} ammonia (NH4OH) is used as acid neutralizer after pickling in circulating cleaning.
This process is a weak acid erosion construction cleaning process suitable for environmental protection, with minimum harm to human body and environmental pollution and safe operation.
2.3.1 the preparation basis of cleaning circuit flow chart is: device process flow chart, cleaning design documents, piping construction drawings and site conditions of each unit of installation project.
There shall be no less than 4 professional cleaning personnel in each shift, and appropriate auxiliary workers shall be equipped.
— the inner wall of the sink is available δ 1mm stainless steel plate or epoxy FRP lining.
The chemical cleaning practice of several sets of petrochemical plants has proved to be safe, effective and reliable.
2.2.1 # chemical cleaning workstation # a) type: container type multi-purpose operation shed, reformed from 8m long standard container.
The chemical cleaning formula is preferred by developed countries in the world.
The cleaning personnel shall be on duty for four shifts and three shifts for eight hours.
2.3.3 be familiar with the process flow, design characteristics and process technical requirements of the cleaned pipeline and equipment, prepare corresponding construction measures, and determine the cleaning methods and quality control measures.
2.2.3 a set of black light for cleanliness inspection, yx-125 portable fluorescent flaw detector (power 125w).
In principle, 12 to 15 people who have experienced chemical cleaning and have certain practical experience shall be organized to form a professional construction team for cleaning.
In principle, the dosage shall be prepared according to 0.5% of the preparation volume, and the dosage shall be adjusted to strictly control the pH value at the neutralization liquid outlet at 9 ~ 9.5 and the operating temperature at about 65 ℃.
2 construction preparation 2.1 cleaning chemicals 2.1.1 sodium hydroxide (NaOH), powder and sodium carbonate (Na2CO3) powder are the main agents used in the chemical cleaning and degreasing process.
