About the interview. . .

Chapter 1: Classification, performance and application scope of engineering materials;

Engineering materials can be divided into metallic materials (ferrous metals and nonferrous metals), nonmetallic materials (polymer materials and inorganic nonmetallic materials) and composite materials. (1) metal material 1. Ferrous metal (1) pig iron and ferroalloy. Pig iron can be divided into steelmaking pig iron and casting pig iron. The alloy of iron with any metal or nonmetal is called ferroalloy. (2) cast iron. It has excellent casting performance, good wear resistance, shock absorption and low notch sensitivity. But also has good heat resistance and corrosion resistance. Cast iron includes gray cast iron, inoculation cast iron, malleable cast iron, nodular cast iron and alloy cast iron. (3) steel. ① The classification of steel is as follows: a. According to chemical composition, steel can be divided into carbon steel and alloy steel. B. According to the classification of smelting quality, steel can be divided into ordinary steel, high-quality steel and high-quality steel. Carbon steel can be divided into structural steel, tool steel and special performance steel. D. According to the classification of smelting methods, steel can be divided into open hearth steel, converter steel and electric furnace steel. According to the degree of deoxidization, steel can be divided into killed steel, semi-killed steel and boiling steel. F. According to the classification of metallographic structure, steel can be divided into sub-* * precipitation, * * precipitation and over-* * precipitation in the annealed state; In the normalized state, steel can be divided into pearlite steel, bainite steel and austenitic steel. G. According to the guarantee conditions at the time of supply, steel can be divided into grade A steel, grade B steel and special steel. (2) steel brand representation. According to the brand, we can see the types, carbon content, alloying elements and their content, smelting quality, properties and uses of steel. For example, the grade of grade A steel is represented by the word "A" plus Arabic numerals 0, 1, 2, 3, 4, 5, 6, 7. Another example is steel grade 20, which is steel with an average carbon content of 0.20%. Another example is 9Cr 18, which represents stainless steel, with an average carbon content of 0.9% and a Cr content of 18%. (3) Main features of foreign steel brands (omitted). (4) the main characteristics and uses of several commonly used steels. A. ordinary carbon steel is divided into grade a steel and grade b steel. Grade A steel is mostly used as reinforcement in construction industry, such as ordinary screws, nuts, washers and bushings. It can also be rolled into plates and profiles (such as I-beam, channel steel, angle steel, etc.). ); The use of grade B steel is the same as that of grade A steel with the same number. B. Ordinary low alloy steel is based on ordinary carbon steel. Adding a small amount of alloying elements not only has excellent properties such as corrosion resistance and wear resistance, but also has high strength and good mechanical properties. C. Cast steel has high mechanical properties, especially high plasticity and toughness, good weldability, but poor castability, and can be used for casting large parts, such as axle boxes, pumps, gears, etc. D. High-quality carbon steel structural steel is mainly suitable for high-quality steel or high-quality steel, and is mainly used for manufacturing mechanical parts. E alloy structural steel belongs to high-quality steel or advanced high-quality steel, which is mainly used to manufacture mechanical parts. F tool steel is divided into carbon tool steel, alloy tool steel and high-speed tool steel; It can also be divided into cutting tool steel, die steel and measuring tool steel. G. Special performance steels include stainless steel, heat-resistant steel, wear-resistant steel, ultra-high strength steel and magnetic steel. Stainless steel not only has excellent corrosion resistance, but also has high strength, hardness and wear resistance. Commonly used stainless steels are Cr 13, 1Cr 18Ni9Ti, Mo2Ti, 00Cr 17Ni 13Mo2. H oxidation-resistant steel, such as 3Cr 18Mn 12Si2N, 2Cr20Mn9Ni2Si2N, etc. Mainly used for manufacturing furnace parts and heat exchangers. 1. Heat-resistant steels, such as 15CrMo,1Cr1mov,1Cr14Ni14w2moni, 4cr1mov. , used for.

J the main brands of low temperature steel are 09Mn2V, 09MnTiCuXt, 06MnNb, 06a1nbsun, 15Mn26A 14, etc. Widely used in refrigeration equipment, oxygen production equipment and manufacturing, storage and transportation equipment of liquefied petroleum gas. 2. Non-ferrous metals (1) copper and copper alloys. Copper is an diamagnetic material with strong corrosion resistance to air and water. Copper has excellent antifriction and wear resistance as well as high elastic limit and fatigue limit. Brass is easy to process, has good corrosion resistance to general atmosphere, marine atmosphere and water, and has good castability. (2) aluminum and aluminum alloys. Aluminum can be used to make containers and tankers containing concentrated acid, but dilute acid and alkali have strong solubility in aluminum. Aluminum alloys are divided into cast aluminum alloys and forged aluminum alloys. Cast iron aluminum alloy includes aluminum-silicon alloy, aluminum-copper alloy, aluminum-magnesium alloy, aluminum-zinc alloy and so on. Deformed aluminum alloys include antirust aluminum alloys, hard aluminum alloys, superhard aluminum alloys and deformed aluminum alloys. (3) Magnesium and magnesium alloys. Magnesium can be used as desulfurizer and deoxidizer when casting copper or nickel alloy, and magnesium is an important nodulizer when casting ductile iron. The elements added to magnesium alloy are aluminum, zinc, manganese, silicon and so on. (4) Titanium and titanium alloys. Titanium has excellent corrosion resistance and heat resistance, is not corroded, and is stable in sulfuric acid, hydrochloric acid, nitric acid, sodium hydroxide and other media. Oxidation resistance of titanium most austenitic stainless steels. Titanium can still maintain high strength at high temperature. The commonly used alloying elements in titanium alloys are chromium, manganese, vanadium, aluminum and molybdenum. (5) Nickel and nickel alloys. Nickel has good chemical stability, corrosion resistance in humid air and seawater, and corrosion resistance in alkaline solutions and organic acids. Nickel also has high thermal stability. (6) Lead and lead alloys. Lead is stable in cold salt and sulfuric acid, has strong acid resistance, and does not react with carbon solutions such as sodium hydroxide and potassium carbonate. Commonly used lead pipes mainly include lead-antimony alloy, hard lead, superhard lead and lead-silver alloy. (II) Non-metallic materials Non-metallic materials include polymer materials and inorganic non-metallic materials 1. Common inorganic nonmetallic materials, etc. (1) cast stone. It is characterized by wear resistance, corrosion resistance, good insulation performance and high compressive strength. (2) graphite. Impermeable graphite, as a corrosion-resistant nonmetallic inorganic material, is widely used in chemical corrosion protection. (3) glass. Timely glass, high silicon glass, borosilicate glass and low alkali boron-free glass. (4) Industrial ceramics. There are also architecture, sanitary ceramics, electric ceramics and chemical and chemical stoneware. 2. Commonly used polymer materials (1) polyethylene (PE) and polypropylene (PP). Low-pressure polyethylene has good rigidity, wear resistance, corrosion resistance and insulation, and is often used to manufacture low-load parts such as plastic pipes, plastic plates, plastic ropes and gear bearings. High pressure polyethylene is soft. Polypropylene (PP) has light weight and good heat resistance, and its mechanical properties such as strength, elastic modulus and hardness are higher than those of low-pressure polyethylene. At the same time, the insulation performance is excellent. (2) PVC. Common products are hard and soft. Rigid PVC has low specific gravity, good tensile strength, good water resistance, oil resistance and chemical corrosion resistance, and many properties are better than polyethylene. (3) polystyrene (PS). It has excellent corrosion resistance and high resistance, is a good heat insulation, shock-proof, moisture-proof and high-frequency insulation material, and has great rigidity. Its disadvantages are poor impact resistance, poor boiling water resistance and limited oil resistance. (4) engineering ABS plastics. It has good comprehensive mechanical properties, stable size, easy electroplating, good heat resistance and corrosion resistance, and still has certain mechanical strength at low temperature. (5) polyamide (PA). Good toughness, high strength and good corrosion resistance. But the heat resistance is poor. Polytetrafluoroethylene (F-4). It has excellent high and low temperature resistance, almost all chemical corrosion resistance, extremely low friction coefficient, no water absorption and excellent electrical properties.

(7) Phenolic plastic (PF). It has certain mechanical strength and hardness, good wear resistance, good insulation and high heat resistance. Excellent corrosion resistance. The disadvantage is that it is fragile and cannot be restored. (8) epoxy plastic (EP). High strength and good toughness; High dimensional stability, good durability and excellent insulation performance. Heat resistance, cold resistance, high chemical stability and good molding process performance. The disadvantage is that it has certain toxicity.

(3) Composite material 1. Performance characteristics of composite materials

The composite material has high specific strength and modulus, good fatigue resistance, good vibration reduction performance of structural parts, good high temperature performance and good fracture resistance. 2. Several commonly used composite materials (1) thermoplastic glass fiber reinforced plastics are reinforced with glass fibers, which have high mechanical properties, dielectric properties, heat resistance and aging resistance, and good technological properties. Thermosetting glass is an engineering material with light weight, high specific strength, good corrosion resistance and excellent dielectric properties. However, the stiffness is poor and it is easy to age and creep. (2) Carbon fiber composites. Compared with glass fiber, carbon fiber has higher strength and ideal elastic modulus, and the strength and elastic modulus remain basically unchanged at high temperature, which is the highest among all heat-resistant fibers. (3) Boron fiber composites have higher compressive strength and shear strength, smaller creep, higher hardness and elastic modulus, higher fatigue strength and radiation resistance. Very stable to water, organic solution, fuel and lubricant. (4) Metal fiber composites. This kind of material is characterized by high strength and high temperature strength, mainly good plasticity and toughness, and is easy to manufacture. Classification (specifications) and performance of common materials such as profiles, plates, pipes, fittings, valves and flanges;

(1) section steel includes ordinary section steel, high-quality section steel, wire rod and rail steel; (2) Plates include steel plates, thin steel plates, steel belts and silicon steel sheets; (3) Pipeline 1. Black metal pipe (1) seamless steel pipe includes seamless steel pipe for boiler, seamless steel pipe for high-pressure boiler, seamless steel pipe for geological drilling, seamless steel pipe for petroleum cracking and seamless steel pipe for stainless steel acid. (2) Welded steel pipes include straight welded pipes and spiral welded pipes. (3) Cast iron pipe. 2. Non-ferrous metal pipes Non-ferrous metals include lead and lead alloy pipes, copper and copper alloy pipes, aluminum and aluminum alloy pipes, titanium and titanium alloy pipes. 3. Non-metallic pipes Non-metallic pipes include concrete pipes, ceramic pipes and clay pipes, glass pipes, glass pipes, graphite pipes, cast stone pipes, plastic pipes and rubber pipes. (4) Pipe Fittings Pipe Fittings include elbows, tees, tees, reducers, steel unions, plugs, threaded nipples, pipe fittings, purging joints, heads, bosses (nozzles) and plates. (5) Valves and valves include gate valves, globe valves, check valves, plug valves, safety valves, regulating valves (throttle valves), ball valves, pressure reducing valves, steam traps, right-angle valves, butterfly valves, diaphragm valves and solenoid valves. (6) Flanges include equipment flanges, pipeline flanges, flange gaskets and flange fasteners.

Classification, Basic Properties and Uses of Common Anti-corrosion and Thermal Insulation Materials (1) Anti-corrosion materials can be divided into polymer materials, inorganic non-metallic materials, composite materials and coatings. (1) Plastic products mainly include polyvinyl chloride, polyethylene, polypropylene and polytetrafluoroethylene. (2) Natural rubber, chlorinated rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, styrene-butadiene rubber and butyl rubber are commonly used in rubber products. (3) FRP and its products. (4) Ceramic products (5) Paint coating includes inorganic zinc-rich paint and antirust primer. (6) Acid-resistant stones, including cast stones, acid-resistant ceramic products, impermeable graphite plates, asphalt-impregnated bricks, etc., are all acid-resistant stones. (7) Acid-resistant cement includes sodium silicate cement and resin cement. (2) Thermal insulation material 1. Classification of thermal insulation materials (1) can be divided into organic materials and inorganic materials according to materials. (2) According to the applicable temperature, it is divided into cold insulation materials, thermal insulation materials, thermal insulation materials and fire-resistant thermal insulation materials. (3) According to the hardness and shape of materials, they can be divided into hard materials, soft materials, semi-hard materials, loose cotton intangible materials and loose materials.

2. Performance requirements of thermal insulation materials

The thermal conductivity of (1) is small, and its value does not exceed 0.12w/(m k) (at 350℃). The value of cold insulation material shall not be greater than 0.064 W/(m k) (average temperature 27℃). (2) Low density, generally below 400kg/m3. The density of cold insulation material is less than 220kg/m3 (3). The material has stable performance, clear heat conduction equation and wide applicable temperature range. (4) Resistant to certain vibration and mechanical strength, such as perlite and microporous calcium silicate products; Compressive strength should not be less than 0. 15MPa. (5) Good chemical stability and no corrosion. (6) Good waterproof performance and low hygroscopicity. (7) Less combustible components should be self-extinguishing or non-olefin. Four, the classification of welding materials (specifications), performance and scope of application

Coated covered electrode consists of coated covered electrode core and coated. The main functions of (1) coated core are conducting electricity, striking arc, making transition alloy and filling metal. (2) The coated covered electrode coating is a layer of coating on the surface of the core wire after raw materials such as ore powder, ferroalloy powder, organic matter and chemical products are prepared in a certain proportion. According to the role of raw materials in welding, covered electrode coating can be divided into: gas-making agent, slag-making agent, deoxidizer, alloying agent, arc stabilizer, binder and plasticizer. (3) Several commonly used covered electrode are as follows: ① The types and properties of carbon steel covered electrode are classified according to the tensile strength, coating type, welding position and current type of deposited metal; ② According to the mechanical properties, chemical composition, coating type, welding position and current type of deposited metal, the covered electrode model and properties of low alloy steel are classified; ③ The types and properties of stainless steel covered electrode are classified according to the chemical composition of deposited metal, covered electrode coating and welding current type; ④ The types and main properties of surfacing covered electrode are classified according to the chemical composition of deposited metal and the type of covered electrode coating. (4) covered electrode brands are named after the main uses and performance characteristics of covered electrode, and they are divided into 10 categories. (5) Please refer to the welding equipment manual for the selection principle of covered electrode.

Section 2 Installation of Construction Machinery

A, installation engineering hoisting machinery. Lifting machinery includes: crawler crane, truck crane, tire crane, tower crane, one-legged pole, herringbone pole, mast crane and cable crane. Second, install engineering-grade transportation machinery. Horizontal transport machinery includes: trucks, trailer groups and pipeline trailers.

Three, the installation of engineering welding machinery. Welding machinery includes: butt welding machine, spot welding machine, arc welding machine (including hand arc welding machine, submerged arc welding machine and argon arc welding machine), electroslag pressure welding machine and pneumatic welding equipment. Section 3 Project Construction Organization Design

First, the role, classification and content of the installation project construction organization design; (a) the role of the project construction organization design (1) to participate in the project bidding and sign the project contract, as part of the bidding and contract documents. (2) To guide the one-time preparation before construction and the whole process of engineering construction. (3) As the plan document of project management, put forward the objectives and technical organization measures of schedule control, quality control, cost control, safety control, site management and various production factors management in engineering construction, so as to achieve the purpose of improving comprehensive benefits. (II) Classification and content of engineering construction organization design 1. The classification of engineering construction organization design is based on the engineering objects of construction organization design, and construction organization design can be divided into three categories.

2. The content of the project construction organization design

Project construction organization includes: the content of pre-bid design; The content of the overall design of the construction organization; Contents of construction organization design for single or unit projects: contents of construction organization design for divisional projects.

Second, the principles and procedures for the construction organization design of the installation project;

(1) Compilation principle (1) Strictly abide by the time limit for construction and the delivery time limit for project completion stipulated in the contract. (2) Reasonable arrangement of construction procedures and sequence. (3) Use flow process and network planning technology to arrange the schedule. (4) Reasonable arrangement of winter and rainy season construction projects. (5) Implement the technical policy of multi-level technical structure, and promote the technical progress and the development of construction industrialization according to local conditions. (6) Proceed from reality, comprehensively balance manpower and material resources, and organize balanced construction. (7) Make full use of existing facilities and local resources, and carefully plan and arrange the site. (8) Implement management by objectives. (9) Combined with construction project management.

(2) Programming Programming includes pre-bid design programming and post-bid design programming. Three, the principle of construction flow operation (a) the elements of flow operation

The elements of flow shop include process parameters, space parameters and time parameters. (II) Classification of Flow Production Flow production is classified according to the organization scope and rhythm of flow construction. (III) Flow Network Diagram The flow network diagram includes horizontal flow network diagram, water interval flow network diagram and overlapping flow network diagram.

(4) Crossplot includes horizontal index plot and vertical index plot. (V) Determination of running water parameters The determination of running water parameters includes the determination of process parameters (construction process, running water intensity), spatial parameters (working face, construction section and construction layer) and time parameters (running water beat, running water interval, technical intermission, organization intermission and flat lap time).

Four. Network schedule planning of construction projects (I) Basic concepts of network planning technology The basic concepts of network planning technology include the basic principles of network planning technology. Basic model of network planning technology. Network planning has certain advantages compared with cross planning. (2) Classification of network plans Network plans are divided into double-code and single-code network plans, single-target and multi-target network plans, time-scale network plans, overlapping network plans, positive 100% positive network plans, local and unit projects and comprehensive network plans.

(3) Engineering network diagram 1. double code arrow diagram

The double code network diagram consists of three basic elements: work, event and line.

(1) Work refers to the implementation activities that can exist independently, such as work procedures, construction processes or construction projects. There is real work and virtual work.

(2) Events refer to numbered circles at both ends of the arrow line in the network diagram, also known as nodes. An event indicates the moment when a job starts or ends.

(3) Line refers to a channel composed of a series of events and arrows from the original events of the network diagram along the arrow direction to the end events of the network diagram. It can be divided into critical circuits and non-critical circuits.

(4) Determine the key work and key lines. The work with zero total maneuver time is the key work, and the line formed by the key work is the key line.

2. Single code network diagram

A single code network diagram needs two basic elements: work and line.

(1) work. In a single-code network diagram, work consists of nodes and related arrows.

(2) ok. In a single code network diagram, the concept, types and properties of lines are basically similar to those in a double code network diagram.

(3) Single code network diagram.

(4) Determine the key work and key lines. The work with zero total working time difference is the key work, and the line composed of key work is the difference key line.

Five, the principles and methods of overall design of construction organization.

(A) the preparation of the construction plan

The preparation of the construction scheme includes the construction deployment, the formulation of the main building construction scheme and the determination of the project development program.

(2) the preparation of the total construction schedule

Calculate the engineering quantity, determine the construction period of each unit project, determine the start-up and completion time and overlapping relationship of each unit project, and prepare the total construction schedule.

(three) the preparation of labor and major technical materials demand plan

Labor force and main technical materials demand plan includes labor force demand plan, main materials and prefabricated products demand plan, main materials and prefabricated products transportation plan, main construction machines and tools demand plan, and large-scale temporary facilities plan.

(4) General layout design of construction

Construction drawing design includes the contents, design basis, design principles and design steps of construction drawing.

Six, single (unit) project construction organization design principles and methods

(A) single (unit) project construction plan preparation

The compilation of a single (unit) project construction plan includes determining the construction direction and procedures, dividing the construction sections, selecting construction methods and machinery, and designing technical and organizational measures.

(two) the preparation of the unit project construction progress plan

Including dividing the project, calculating the engineering quantity and determining the construction period, determining the construction sequence, organizing the flow process and drawing the construction progress plan.

(3) Construction preparation plan and resource guarantee plan

Including construction preparation work plan, unit engineering labor demand plan, unit engineering main material demand plan, unit engineering component demand plan and unit engineering construction machinery demand plan.

(4) Design of unit project construction scheme

Including the design content, design requirements and design steps of the unit project construction drawing.

Chapter II Basic Knowledge of Construction Technology

This chapter introduces the basic knowledge of construction technology, including the basic contents of welding, anti-corrosion, heat preservation and related specifications commonly used in installation engineering, the functions and methods of heat treatment, the functions and methods of degreasing, pickling, passivation and prefilming, and the basic procedures and technological processes of hoisting construction and construction engineering quality inspection;

Section 1 Cutting and Welding

1. Common cutting methods in installation engineering, characteristics and application scope of various cutting methods, including oxygen cutting, plasma cutting, carbon arc gouging and laser cutting.

(1) oxygen cutting

1. Conditions of gas cutting metal

The melting point of (1) metal oxide should be lower than that of metal.

(2) The combustion of metal and oxygen can release a lot of heat, and the thermal conductivity of metal itself is low.

2. The scope of application of gas cutting

Gas cutting is suitable for pure iron, low carbon steel, medium carbon steel, low alloy steel and titanium.

3. Gas cutting process parameters

The technological parameters of gas cutting include preheating beet root rate, oxygen pressure, cutting speed, the distance between cutting time and workpiece surface and the inclination of cutting torch.

(2) plasma arc cutting

The temperature of plasma arc column is high, and the cutting process is completed by melting, so most metal and nonmetal materials can be cut.

The commonly used gases in plasma arc cutting are argon, nitrogen, helium plus argon mixture, nitrogen plus argon mixture and so on. The technological parameters of plasma arc cutting include cutting current, no-load voltage, cutting speed, gas flow, nozzle height from workpiece and so on.

(3) carbon arc gouging

Carbon arc gouging is a cutting method which uses carbon rod or graphite rod as electrode, the arc generated between carbon rod and workpiece melts the metal, and the molten metal is blown away by compressed air. The characteristics, application scope, process parameters and possible defects of carbon arc gouging are shown in relevant materials.

(4) laser cutting

It is a method of cutting materials with high energy density laser as a "cutting tool". There are laser gasification cutting, laser melting cutting, laser oxygen cutting, dicing and fracture control.

Second, the classification, characteristics, selection and classification code of welding methods

(A) the classification and characteristics of welding methods

(1) Welding arc welding includes manual arc welding, submerged arc welding, tungsten gas shielded welding, plasma arc welding, metal gas shielded welding, etc.

(2) Resistance welding includes electroslag welding with slag resistance heat as energy source and resistance welding with solid resistance heat as energy source.

(3) High energy beam welding includes electron beam welding and laser welding.

(4) Brazing is divided into flame brazing, induction brazing, furnace brazing, immersion brazing and resistance brazing.

The above are the characteristics and scope of application of various welding methods.

(2) Selection of welding method and classification code

The factors to be considered when selecting the welding method are:

(1) product features. Including the structural characteristics of welded products, workpiece thickness, joint form, welding position and parent material performance.

(2) Production conditions, including operation level, welding equipment and welding materials.

(3) The welding method code refers to the code indicating the welding method by numbers or letters.

Section 2 Heat Treatment

First, familiar with the basic concept and significance of heat treatment.

The operation process of heating metal to a given temperature and keeping it for a period of time, and then cooling it at a selected speed and method to obtain the required structure and properties is called heat treatment.

Heat treatment of welded joints can prevent brittle failure, delayed crack, stress corrosion and hydrogen corrosion of welded parts. Correct heat treatment can relax welding residual stress, soften hardened zone, improve microstructure, reduce hydrogen content, and improve corrosion resistance, impact toughness and creep limit.

Second, familiar with the role and general requirements of preheating before welding and heat treatment after welding, and familiar with their heating methods.

(1) preheating before welding

The function of preheating is to reduce the temperature between the weld metal and the base metal, thereby reducing the shrinkage stress (thermal stress), reducing the cooling rate of the weld, controlling the microstructure transformation of the steel, alleviating local hardening and improving the quality of the weld. It can also reduce defects such as air holes and slag inclusion.

Usually, the preheating temperature of 35# and 45# steel can be 150~250℃, and it can be increased to 250~400℃ when the carbon content continues to increase or the hardness of the workpiece is high. The heating range of local preheating is 150mm~200mm on both sides of weld.

(2) heat treatment after welding

The function of post-weld heat treatment, the selection of heat treatment specifications, the general requirements of post-weld heat treatment and the heating mode of post-weld heat treatment are detailed in relevant materials.

(3) integral heat treatment

The whole heat treatment is to eliminate welding stress, stabilize various geometric dimensions and change welding phase.

Structure, improve the toughness and stress resistance of metal, and prevent cracks.

Section 3 degreasing, pickling and passivation

A, chemical production equipment, pipelines, etc. During construction, the oil-repellent system must be degreased as required. Carbon steel, stainless steel and copper pipes, fittings and valves should use industrial carbon tetrachloride, aluminum alloy pipes, fittings and valves should use industrial alcohol, and nonmetallic gaskets can only use carbon tetrachloride.

(A) degreasing method

Degreasing of pipes and pipelines, degreasing of pipeline accessories and gaskets, carbon steel, stainless steel and copper pipes, fittings and valves should use industrial carbon tetrachloride, aluminum alloy pipes, fittings and valves should use industrial alcohol, and nonmetallic gaskets can only use carbon tetrachloride.

(2) Defatting inspection

Degreasing inspection can be divided into direct method and indirect method.

Second, the requirements, scope of application and common methods of pickling

During the construction, if there are special cleaning requirements for the inner wall of equipment and pipelines, pickling should be carried out. Pickling is usually carried out by tank immersion method and system circulation method. Pickling should be carried out in strict accordance with the requirements. After pickling, pipes and equipment must be passivated quickly.

Three. Passivation and Common Passivation Methods (omitted)

Section 4 Insulation and Anti-corrosion

Type, purpose, scope, form and construction method of thermal insulation structure

The insulation of equipment and pipelines can be divided into three types according to their purposes: insulation, heating insulation and cold insulation.

(1) insulation range

The temperature range of equipment and pipelines is-196 ≤℃≤ 850.

(2) Thermal insulation structure form

In thermal insulation engineering, the thermal insulation structure consists of anti-corrosion layer, thermal insulation layer and protective layer. Moisture barrier and gas barrier should also be added to the cold insulation structure.

Thermal insulation structure includes coating, filling, wrapping, compounding, pouring, spraying, prefabricated blocks and other structural forms and installation methods.