Fangkuai boiler engineering construction drawing design

Heat Engine Section, Volume 5, Volume 1

Thermal insulation paint construction instructions and

Inventory of materials

directory

1. Overview

2. Performance of insulation materials

3. Insulation structure and construction instructions

4. Paint and anti-corrosion

5. Insulation description table

6. Summary table of thermal insulation protection materials

7. Paint description sheet

8. Paint summary table

1 Overview

1.1 Design basis

The national standards and the latest industry standards on which the design of this book is based are as follows:

1.1.1 "Design Code for Thermal Insulation Paint of Thermal Power Plant" (DL/T 5072-2019).

1.1.2 "Guidelines for the Design of Equipment and Pipeline Insulation" (GB/T 8175-2008).

1.1.3 General Principles for Equipment and Pipeline Insulation Design Technology (GB/T 4272-2008).

1.1.4 "Testing and Evaluation of Insulation Effect of Equipment and Pipelines" (GB/T 8174-2008).

1.1.5 "Code for Construction Quality Acceptance of Industrial Equipment and Pipeline Insulation Engineering" (GB50185-2010).

1.1.6 "Code for Design of Thermal Insulation Engineering of Industrial Equipment and Pipelines" (GB50264-2013).

1.1.7 Code for Construction of Industrial Equipment and Pipeline Insulation Engineering (GB50126-2008)

1.1.8 Technical Code for Thermal Equipment and Pipeline Insulation and Anti-corrosion Construction of Thermal Power Plant (DL 5714-20 14).

1.2 Design Scope

The design scope of Fangkuai engineering insulation paint includes the following parts:

1.2.1 Equipment and soda pipes.

1.2.2 Equipment and smoke, wind, pipes.

Some of the equipment and piping of the chemical water specialty.

associated platforms and escalators.

Note 1: The equipment and the platform and escalator supplied with the equipment will not be repainted if the manufacturer has already painted, but only touch-up.

Note 2: The material table in this volume shows the consumption of two boilers.

Principle of heat preservation

1.3.1 General Provisions

1) All equipment, pipes and accessories with an outer surface temperature higher than 50 °C and need to reduce heat dissipation shall be insulated;

2) The exhaust pipe of the safety valve shall be insulated at the place where it intersects with the cable;

3) The part that needs to be prevented from being scalded by personnel is insulated (generally insulated within the range of 2500mm above the floor, and the horizontal distance of the operating platform is 750mm).

4) The equipment and pipelines arranged in the open air are anti-freezing, anti-condensation or delay the condensation of the medium, and the thickness of the insulation material should be uniformly selected as 50mm.

1.3.2 After insulation, the temperature of the outer surface of the protective layer shall not exceed 50 °C when the ambient temperature is not higher than 27 °C; The ambient temperature can be 25°C higher than the ambient temperature above 27°C. For anti-scald insulation, the temperature of the outer surface of the insulation structure should not exceed 60°C.

1.3.3 The thickness design of the insulation material is calculated according to the economic thickness method.

1.4 Paint Principles

1.4.1 For equipment, pipelines and their accessories (including support and hangers), platform escalators, etc., which are not insulated and the medium temperature is lower than 120 °C, external painting should be carried out.

1.4.2 Circulating water pipes, boxes and tanks are painted internally according to different requirements.

1.4.3 The part of the pipeline that is not insulated after the safety valve shall be coated with high-temperature resistant paint for anti-corrosion.

1.4.4 The outer surface of the pipeline or the outer surface of the insulation structure shall be painted with the name of the medium and the arrow of the flow direction of the medium. The outer surface of the equipment or the outer surface of the insulation structure is painted only with the name of the equipment.

1.4.5 Buried pipelines shall be treated with anti-corrosion as required.

2. Insulation material performance

2.1 Primary insulation material

2.1.1 In order to ensure the quality of the insulation project and strictly control the quality of the material, the physical and chemical performance test report of the insulation material must be the original document provided by the statutory testing agency with the corresponding national qualification according to the national standard.

The following features should be listed in the report:

Thermal conductivity equations, graphs, or tables.

Density.

Maximum operating temperature.

Incombustibility.

5) Rigid insulation products should have compressive strength, mass moisture content, linear shrinkage, flexural strength, etc.

6) Soft insulation materials and semi-rigid products should have slag ball content, average fiber diameter, organic matter content, heating permanent line change, moisture absorption rate, hydrophobicity rate, etc.

7) No corrosion on equipment and pipeline surface.

2.1.2 Insulation material suppliers must have three certificates:

2.1.2.1 The inspection report tested by the National Fiber Materials Monitoring Center must be provided

2.1.2.2 Power industry insulation refractory supply license, designated products must be aluminum silicate products or glass wool products

2.1.2.3 Production license

2.1.3 The insulation material of this project is made of aluminum silicate cotton (fiber) products (felt, board, rope).

1) Aluminum silicate cotton (fiber) products (felt, board, rope)

It is used for the insulation of steam and water pipelines, hot air pipelines and equipment of the whole plant. Its performance indicators are as follows:

Density of use: 128 kg/^m3

Slag Ball Content: <20% (Particle Size >0.21mm)

Heating Permanent Line Variation: <5% (average temperature 500°C±10°C)

Al2O3 content: ≥40%.

Al₂O₃+SiO₂： ≥95%

Tensile strength: ≥35 /kPa

Thermal conductivity ₀: ≤0.056 (average temperature 70 °C) W/(m .k).

Thermal conductivity equation: ₀ +0.0002 (t_m-70) W/(m .k) (t_m≤400°C).

₀ ＋0.0002（t_m-70）＋0.00036（t_m-400）（t_m>400℃）

Recommended operating temperature: <800 °C

Non-flammable: Non-flammable

2.2 Protective Layer Material

The protective layer is used outside the insulation layer of pipelines and equipment in the whole plant to protect the insulation layer, waterproof, moisture-proof and anti-atmospheric corrosion.

The protective layer material of this project is made of color steel plate or color steel plate

(1) The thickness of 0.7mm is used for the pipe with an outer diameter of ≥ ø800mm after insulation, and the thickness of 0.5mm is used for the rest of the pipe;

(2) The equipment and rectangular section smoke and air ducts are made of corrugated color steel plates with a thickness of 0.7mm;

For details, please refer to Table 5 of the insulation instructions.

2.3 Moisture-proof layer material

The moisture-proof layer is used for the insulation layer of pipelines and open-air pipelines and equipment in the trench, which is waterproof and moisture-proof.

The moisture-proof layer material must be resistant to steam leakage, waterproof, moisture-proof, fireproof and flame-retardant; Chemically stable, non-toxic and corrosion-resistant; does not soften, bubble and do not run in summer; At low temperatures, it does not embrittle, crack, or fall off.

The moisture-proof layer of this project adopts flame-retardant coated plastic anti-corrosion reflection moisture-proof belt, with a thickness of 0.2mm, a tensile strength of ≥50MPa, and an impermeability of 0.58MPa, the water absorption rate is not more than 1.0%, and there is no water seepage for 30min.

3. Insulation structure and construction instructions

3.1 General

1) The insulation structure is generally composed of an insulation layer and a protective layer. For pipes in trenches and low-temperature pipes and equipment in humid environments, lay a vapor barrier outside the insulation layer.

2) The insulation structure should be able to remain intact during the design service life, and burns, rots, peeling and other phenomena are not allowed during use.

3) The insulation structure should have sufficient mechanical strength to not be damaged under the action of additional loads such as self-weight, vibration, wind and snow.

3.2 Thermal insulation structure

 
1) Pipeline (pipe outer diameter > 38mm), → aluminum silicate cotton felt→ barbed wire (flame retardant coated plastic, anti-corrosion, reflective and moisture-proof belt is used outdoors), → color steel plate or aluminum plate.

3) Pipes with an outer diameter of ≤38mm→ aluminum silicate fiber rope→ barbed wire→ metal anti-corrosion adhesive tape

4) Flat wall, equipment→ glass wool board or aluminum silicate cotton board→ barbed wire (flame retardant coated plastic, anti-corrosion, reflective and moisture-proof belt is used outdoors), → corrugated color steel plate.

3.3 Construction Instructions

3.3.1 The quality inspection of the insulation materials used should be carried out before the insulation construction. The performance of insulation materials and their products must meet the design requirements. The inspection method shall be carried out in accordance with the "Quality Inspection and Evaluation Standards for Industrial Equipment and Pipeline Insulation Engineering" (GB50185) and the "Code for Construction and Acceptance of Industrial Equipment and Pipeline Insulation Engineering" (GB50126).

3.3.2 During the insulation construction, the insulation material should not be damp. Especially for outdoor insulation, construction should be carried out in a rainless day, so that the main insulation layer and the protective layer are carried out at the same time, and there are rainproof emergency measures.

3.3.3 Pipeline insulation should be carried out after the installation of all components (including instrument test pipes, ladders, platforms, etc.) is completed and the tightness test is qualified. Dirt such as oil, rust and mud must be removed from the surface of the pipeline before construction.

3.3.4 During the construction, the short pipe, flange and manhole on the equipment should be exposed outside the insulation structure, and the insulation of the short pipe extending out is consistent with the insulation of the pipeline connected to it.

3.3.5 The insulation structure of the pipeline creep monitoring section, creep measurement point, flow measurement device, valve, flange, plug plate, compensator and other parts is made into a detachable structure to meet the needs of operation inspection and maintenance.

3.3.6 Layered insulation

1) The thickness of the insulation layer should be 10mm as the binning unit, and the thickness should be more than 80 mm, and the layered laying should be adopted, and the thickness of each layer should be roughly equal. When laying, the same layer should be staggered, the inner and outer layers should be pressed joints, and there must be no gaps between layers and seams to reduce heat loss.

2) During the construction of soft insulation products, the compression ratio of the material should be mastered. The thickness must meet the design requirements, the butt seam and the ring seam should be tightly bandaged, and the spacing of the binding wire should be evenly proportioned and tight.

3) Reinforcement measures should be taken for the insulation layer of the empty exhaust pipeline after the safety valve.

4) The insulation structure of the air layer should be used for the insulation of the giant large-section flue duct and the rotating machinery, and the thickness of the insulation layer can be adjusted when the thickness of the insulation layer is less than the height of the reinforcing rib.

5) The insulation structure of the bundle insulation should be tied every 2~3 meters to block the gaps of the dead pipe bundle to prevent air convection.

6) The insulation structure can be adjusted locally or the insulation thickness can be reduced as needed near the beam, wall, platform wall or intersection of the pipeline.

7) The thickness of the insulation layer of the pipe with an outer diameter of ≤ 38mm, 50~70mm when the medium temperature is higher than 300 °C, and 20~50mm when it is lower than 300 °C.

8) The filling material of the thermal insulation expansion joints and gaps of equipment and pipelines should be made of soft fibrous materials according to the medium temperature, aluminum silicate cotton should be selected for 300 °C and above, and glass wool should be selected for less than 300 °C.

9) The equipment with noise exceeding 85dB(A) shall be insulated with sound-absorbing materials or the insulation structure of the equipment with sound insulation effect.

3.3.7 Insulation structure support settings

1) The insulation layer of vertical equipment and pipes, inclined pipes with a horizontal angle greater than 45° and horizontal equipment should be provided with supporting parts. For flue air ducts and equipment with reinforcing ribs, the reinforcing ribs should be used as supporting parts.

2) The position of the supporting parts should avoid valves, flanges and other pipe fittings, and for equipment and risers, the supports should be located above the valves, flanges and other pipe fittings, and their positions should not affect the disassembly of bolts.

3) The material selected for the support is suitable for the temperature of the medium.

4) When the medium temperature is less than 430 °C, the bearing parts can be welded bearing rings; When the medium temperature is higher than 430°C, the bearing part should adopt a tight hoop bearing ring. When direct welding to equipment or pipelines is not permitted, tight hoop load-bearing rings should be used. When directly welded on the stainless steel pipe, the stainless steel backing plate should be welded.

5) When using soft insulation materials and semi-rigid products, in order to ensure the neat and beautiful appearance of the metal protective layer, a metal skeleton should be appropriately set up to support the metal protective layer.

6) For all equipment that needs to be heat treated after welding, the welding supports on it should be pre-welded in the equipment manufacturing plant.

7) The bearing surface width of the supporting part should be 10mm~20mm less than the thickness of the insulation layer.

8) The spacing of the supporting parts: 1.5m~2m for equipment or flat wall, 2m~3m for pipelines at 350°C and above, 3m~5m when 350°C and below, and 1m when the pipeline is insulated with soft insulation materials felt and pads; Horizontal equipment should be provided with a support at the horizontal centerline.

3.3.8 Fixtures (anti-rust fasteners) of the insulation structure are set

1) The insulation layer of pipes, flat walls and cylindrical equipment, and soft materials should be fixed with pins and self-locking gaskets when insulation.

2) The hook nails and pins used for fixing the insulation layer can be made of low-carbon round steel of φ3~φ6.

3) When soft materials are insulated, the distance between nails should not be greater than 350mm. The number of nails per square meter of area: no less than 6 on the sides and 8 on the bottom.

4) For places with vibration, hook nails or pins should be appropriately thickened and encrypted.

5) The fixing parts directly welded to stainless steel equipment or pipelines must be made of stainless steel. When the fixing parts are made of carbon steel, stainless steel backing plates should be welded.

6) For all equipment that needs to be heat treated after welding, the welding fixing parts on it should be pre-welded in the equipment manufacturing plant.

7) When the wall thickness is not more than 4mm, the hook nail welding and fixing should be carried out before the equipment and pipeline tightness test, and when welding is not allowed, it can be carried out according to the provisions of the equipment technical documents.

3.3.9 The strapping parts of the insulation structure shall meet the following requirements:

1) The insulation layer should be bundled with galvanized iron wire or galvanized steel belt, and the galvanized iron wire should be double-stranded.

The specifications of the bundle shall be in accordance with the provisions of Table 3.3.9.

Table 3.3.9 Specifications of strapping parts mm

2) Spacing between strapping: soft insulation products should not be greater than 200mm. At least two pieces of insulation should be bundled on each piece of insulation products.

3) When the insulation layer is laid in layers, it should be bundled layer by layer, and the parts with vibration should be properly strengthened.

4) Spiral winding and bundling shall not be used.

3.3.10 When the pipeline is insulated, a gap should be left at the following pipe sections, and the joints should be filled with soft insulation materials, and then wrapped with color steel plates.

1) The connection of pipeline valve and flange must leave a disassembly gap, and the length shall be subject to the disassembly bolt, generally the length of the bolt is 20~30mm.

2) When two insulation pipes that cross or parallel to each other are not the same in the direction of expansion or the temperature of the medium, a gap of 10~20mm should be left between the protective layers of the two pipelines.

3) The insulation structure near the compensator and the support and hanger should leave enough clearance to make the insulation structure not damage when the pipeline expands and contracts.

4) At the creep measurement point of the high-temperature pipeline, a gap of 200mm should be left in the insulation layer, and the gap should be filled with soft insulation materials.

5) An expansion gap should be set between the insulation structure and the fixed components such as walls, beams, columns, railings, platforms, supports, and the cavities through which the pipelines pass.

3.3.11 Key points of metal protective layer construction

1) The longitudinal joints of the metal protective layer of soft insulation materials and their semi-rigid products are lapped or plugged. The lap size shall not be less than 30mm. Mortise seams are fastened with self-tapping screws or blind rivets, and lap seams are secured with blind rivets. The distance between the nails should be 150mm~200mm. When the outer diameter of the insulation layer is greater than 600mm, the longitudinal seam can also be made into a convex rib structure and fixed with blind rivets.

2) The circumferential seam of the metal protective layer adopts lap joint or plug joint. When lapping, one end should be pressed out of the convex rib structure (indoor with single convex bar, outdoor with overlapping rib), the lap size shall not be less than 50mm, and the vertical pipe and inclined pipe should be fixed with self-tapping screws or blind rivets. The spacing between the nails is 200mm, and each seam should not be less than 4 nails. When the metal protective layer is fixed with a support ring, the nail hole should be aligned with the support ring.

3) Fix the place with self-tapping screws, drill holes with a portable electric drill, and it is forbidden to install screws with punching or other inappropriate ways.

4) The longitudinal seam of the horizontal pipeline should be set on the side of the pipeline, the circumferential joint of the horizontal pipeline should be built with low stubble according to the slope, and the circumferential joint of the vertical pipeline should be built up and down.

5) The metal protective layer should have an overall waterproof function. The equipment and pipelines in the outdoor layout or humid environment should be filled with sealant or cement to be tightly jointed, the installation nail holes should be plugged with epoxy resin, and the horizontal pipe part of the open-air support and hanger should be installed with a rain cover on the boom where the color steel plate is penetrated, and the vertical pipe part should be installed with a rain cover at the pipe part.

6) The length of the metal shell on the straight pipe section is generally 500~900 mm, and the unfolded width is the lap size of the outer circumference of the insulation layer plus 30~40 mm. The blanking length of the metal casing of the pipe elbow can be 1.3 times the circumference of the outer circle of the insulation, or it can be slightly shortened according to the actual situation.

7) The metal protective layer of the insulation layer of large equipment and storage tanks should be made of profiled plates or vertical ribs, and should be reinforced by the circumferential direction of the metal hoop belt connected by springs. The so-called convex rib structure is to put the color steel plate on the wire shaker to press out the rib, and leave a straight edge of 5~10 mm wide, and the arc diameter of the rib is generally shown in Table 3.3.11-1:

Table 3.3.11-1

8) The circumferential seam of the metal protective layer set for thermal expansion on the straight pipe should be in the form of movable lap joint. The movable lap margin should be able to meet the requirements of thermal expansion, and not less than 100mm, and its spacing should meet the following requirements:

a) Movable hoop joints of soft insulation materials and semi-rigid products shall comply with the provisions of Table 3.3.11-2:

Table 3.3.11-2 Table of movable hoop seam spacing

9) When the metal protective layer is constructed on the flat wall, the keel is welded on the outer wall of the main insulation material first. With δ = 2 ~ 3mm, width 20 ~ 30mm flat steel welded into a protective layer to fix the keel, the distance between the flat steel and the wall is not greater than the thickness of the insulation, the vertical and horizontal distance is 500 ~ 600mm, and then the color steel plate is fixed on the keel.

10) The top of the protective layer of the large cross-section rectangular air duct arranged outdoors should be set with a drainage slope and double-sided drainage.

3.3.12 Key points of moisture-proof layer construction

1) The moisture-proof layer is made of flame-retardant plastic-coated anti-corrosion reflection moisture-proof belt, and the circumferential and longitudinal seam lap should not be less than 50mm.

2) Hard straps such as galvanized iron wires or steel belts shall not be set outside the moisture-proof layer.

4 Paint and antiseptic

4.1 Paint

4.1.1 Pretreatment of steel surface before painting

1) Before pretreatment, the oil and dirt, burrs, welding slag, loose oxide scale, rust, coating, etc. on the surface of the steel should be removed.

2) The pretreatment of the steel surface should be based on the corrosion grade of the steel surface, and the rust removal should be carried out by spraying, manual or power tools, and the specified rust removal grade should be reached.

Table 4.1.1 Rust removal grade on steel surface

Sa- stands for jet rust removal method

ST- stands for manual and power tool rust removal method

3) After the rust removal is qualified, the primer should be applied in time, and the interval should not exceed 5 hours after spray rust removal; After the derusting of hand and power tools, the primer should be applied on duty.

4.1.2 Coatings for equipment, pipelines and ancillary steel structures

4.1.2.1 Coatings for equipment and pipes that are not insulated

1) Equipment, pipes and ancillary steel structures arranged in the interior are made of alkyd paint.

Exterior equipment, piping and ancillary steel structures with polyurethane coatings.

2) Epoxy coating is used for the outer wall of oil pipelines and equipment;

The outer wall of the oil tank is made of weather-resistant heat-reflective heat-insulating coating;

The inner wall of the fuel tank is made of epoxy oil-resistant coating;

The inner wall of the oil tank is made of oil-resistant electrostatic conductive coating;

3) Pipes in pipe trenches are painted with epoxy asphalt paint.

Circulating water pipelines, industrial water pipelines, industrial water tanks, etc., adopt epoxy asphalt coatings;

The inner wall of the circulating water pipeline is made of epoxy asphalt coating.

5) For the exhaust pipeline, polyurethane heat-resistant coating or silicone heat-resistant coating is used according to the medium temperature.

6) The equipment and hangers supplied by the manufacturer should be coated with a topcoat of the same color at 1~2 degrees.

7) Overhead stainless steel pipes are coated with 1~2 degree topcoat, and directly buried stainless steel pipes are coated with 1~2 degree primer.

4.1.2.2 Coatings for insulating equipment and pipes

1) When the medium temperature is lower than 120°C, the surface of the equipment and pipeline should be coated with 1~2 degree epoxy zinc-rich primer.

2) The inner wall of the trap tank, expander, low-level water tank, production return tank and other equipment is coated with a 2-degree high-temperature resistant primer.

4.1.2.3 The indoor steel platform escalator and the on-site support and hanger are made of alkyd coating;

Exterior steel platform ladders and hangers in polyurethane paint.

4.1.3 Coating dry film thickness and paint degree

The coating is generally composed of a primer, an intermediate coat and a topcoat, and is used together, as shown in the following table:

Table 4.1.3

4.1.4 Painting construction requirements

1) The ambient temperature of the construction site should be 10°C~30°C, and the ambient humidity should not be greater than 85%. The surface temperature of the steel must be 3°C above the dew point temperature.

2) Under strong wind, rain, fog, snow and strong sunlight, outdoor construction is not suitable.

3) Before the next coating of the surface of the secondary coating, the surface salt, oil, mud, dust and other dirt should be removed, and then the original paint film should be haired, and finally repaired according to the original design.

4.1.5 In the process of coating construction, the relevant national and industry regulations on fire prevention, explosion prevention and poison prevention must be observed.

4.1.6 Quality inspection and acceptance

1) The appearance of the coating should be smooth and flat, and the color should be uniform and consistent;

The surface of the coating should be free of pinholes;

The thickness of the coating should be uniform, and the thickness of the dry film must be greater than or equal to the design thickness;

The coating should be free of leakage and no coating.

2) Coating acceptance includes intermediate acceptance and delivery acceptance, and shall not be delivered without delivery acceptance.

4.1.7 The name of the medium and the arrow of the medium flow direction of the pipeline

 
For identification, the pipe writes the name of the medium and the arrow of the flow direction of the medium, and the device only writes the name.

1) Pipe elbows, wall penetrations and dense and indistinguishable parts of pipes must be painted with signs. Overhead pipes are painted on straight pipe sections according to the principle of uniform distribution and easy observation.

2) The position and shape of the medium name and the medium flow direction arrow of the pipeline are shown in the figure. The dimensions in the figure are shown in Table 4.1.7, and the sharp angle of the medium flow direction arrow is 60°.

Table 4.1.7 (Unit: mm)

3) When there are two possibilities for the flow direction of the medium, the flow direction arrows in both directions should be marked.

4) The medium name and flow direction arrows are painted with black or white paint.

5) For pipelines with an outer diameter of less than 76mm, when the name of the medium and the arrow of the medium flow direction are directly painted on the pipeline, signs can be hung at the parts that need to be identified. The name of the media should be indicated on the signage, and the sharp corners of the sign should point to the flow direction of the medium.

4.1.8 Paint color of pipelines and equipment, see Table 4.1.8 for details.

Table 4.1.8

4.2 Antiseptic

The buried pipeline is anti-corrosion with epoxy coal asphalt coating, the anti-corrosion grade is to strengthen the anti-corrosion, and the structure of the anti-corrosion layer is: asphalt primer - asphalt 5 layers and 4 layers of glass cloth, and the total thickness of the coating is not less than 1.0mm.