This regulation applies to the heating and insulation design of instruments and pipelines in chemical plants. HG/T 20514-2000 Instrument and pipeline heating and insulation design regulations (with clause explanation) HG/T20514-2000 standard download decompression password: www.bzxz.net

Industry Standard of the People's Republic of China
Design Code for Tracing and Insulation of Instrument and Piping
HG/T20514-2000
Main Editor: Jilin Chemical Engineering Company
Approving Department: State Bureau of Petroleum and Chemical Industry Implementation No. 6: 00 One Day, One Month, One River
1.0.1 This regulation applies to the design of tracing and insulation of instruments and pipelines in chemical equipment. 1.0.2 The insulation of instruments and measuring pipelines can ensure that the materials in the sealing system of the connection process will not freeze, condense, crystallize, precipitate, vaporize, etc., and can ensure that the instruments are within the operating temperature range allowed by the technical conditions. 1.3 For measuring pipes, instruments and their auxiliary equipment that do not work normally at ambient temperature, insulation design can be carried out according to the requirements of this regulation.
1.4 When implementing this regulation, it should also meet the requirements of the relevant current national standards. 277
2 Heating, insulation and heat preservation
2.1 Steam heating
2.1.1 Steam heating should be used for any of the following conditions: 1. Measuring tubes and detection instruments for materials that may freeze, cool, crystallize, precipitate, etc. at ambient temperature;
Analysis and sampling pipelines that may freeze at ambient temperature; 2.
Instruments that cannot meet the minimum ambient temperature requirements. 2.2 Hot water tracing
Hot water tracing can be used in any of the following conditions: 2.2.1
Detection systems that are not suitable for steam tracing; 1www.bzxz.net
In the absence of steam source
2.3: Electric tracing
Electric tracing can be used in any of the following conditions: The same conditions as 2.1.1;
Occasions where remote and automatic control of the tracing system is required; Occasions where the cleanliness of the environment is required to be high: Occasions where there is no other heat source.
2.4 Insulation and heat preservation
Insulation and heat preservation should be used in any of the following conditions: 2.41
1For instrument detection systems of hot fluids such as steam, hot water or other commercial temperature materials; For cold fluid instrument detection systems
3When the use of insulation can ensure the normal operation of instruments and pipelines, insulation and heat preservation should be used without heating.
2.5 Regulations on temperature considerations in thermal insulation design 2.5.1 The expansion of the medium in the instrument pipeline: 20~80%. 2.5.2 The temperature in the insulation box under the ambient temperature: 15~209. 2.5.3 For the insulation system in the open air environment, the atmospheric temperature should be the local extreme minimum temperature, while the insulation system installed indoors should be calculated based on the indoor low temperature. The insulation structure and materials of the meter pipeline
2.6.1 The insulation structure is composed of two parts: the insulation layer and the green protective layer. The insulation of the meter pipeline can be done by the on-site binding method of the pipeline temperature probe, or by the pipeline method of measuring pipeline, heating pipe insulation layer and protective layer: Figure 2.6, 1 insulation structure
In the figure: 1-steam pipe: 2 instrument pipeline: 3-anti-corrosion oil seat (optional): 4 insulation layer: 5-chain zinc iron solution; 6-missing wire. The materials for the insulation layer of the binding tape shall be selected according to the following principles: 2+6.2
Thermal conductivity is less than 0.081 kg/m3: C:
Density is less than 350 kg/m3;
It has a certain mechanical strength and its compressive strength is greater than 0.3 MPa: It has good thermal stability, its hardness does not decrease when the temperature changes, and it does not produce dust embrittlement phenomenon: 4
Chemically stable, no effect on metal: The material has low water absorption rate
It is non-flammable or flame retardant;
Convenient construction and low price
The characteristics of the insulation layer materials used for the binding tape are shown in Table 2.6.3. Table 2.6.3
Testicular foam plastics
Calcium silicate products
Glass wool
Polystyrene plastics
100~200
30 ~60
170~240
Commonly used moisturizing materials
Thermal conductivity
W/(m·)
0. 055 - 0. 064
The heating type is divided into heavy heating and light heating:
Heating method
Recommended operating temperature
-65~80
65 ~70
1Heavy heating means that the heating pipeline is connected to the meter and instrument measuring pipeline, as shown in Figure 2.7.1 [BD) 2Light heating means that the heating pipeline does not contact the instrument and meter measuring pipeline or a thick asbestos board is added between them, as shown in Figure 2..1A, C):
The corresponding heating form should be determined according to the characteristics of the medium, see Figure 2.7.1. 3
Figure 2. 7. 1
Heating structure enclosure
In the figure: A—single pipe fitting heat: B—single pipe fitting heat: C—single pipe fitting heat: D—multiple pipe fittings heat. 280
Insulation design
Insulation thickness gauge
Only the insulation thickness of the instrument pipeline 6Continue the above formula to calculate: 9=3.6.
I - ta
9. Allowable thermal head of the instrument pipeline, (m·b); D
- The outer diameter of the instrument pipeline after insulation, m;
4- The current outer diameter of the instrument pipeline,;
The medium temperature in the instrument pipeline, ℃
Atmospheric temperature, % (the lowest limit temperature in the use area):- The thermal conductivity of the insulation material, W/(·C): P- The circumference of the cross section of the instrument pipeline, m:
8.--The thickness of the insulation layer, me
(3. 1. 1 - 1)
(3. 1. 1 - 2)
[3. 1. 1 - 3]
[3. 1.1 - 4]
(3. 1. 1 - 5)
3.1.2 Insulation thickness of insulation layer 5, calculated according to the following formula; 4=3.6
Wherein 4-
3. 6(h-t)4
- allowable heat absorption loss on the surface of insulation box, (m,)--temperature inside insulation box, note (should meet the requirements of 2.5.2) thickness of insulation layer of product testing box, m.
3.1.3 The heat loss of the electric heating instrument pipeline is calculated according to the following formula: =
Wu Zhong-
Heat loss of one unit length of pipeline, m
(3. 1. 2 -1)
(3. 1.22)
(3. 1. 3)
The allowable heat loss value of the instrument pipeline can be taken as the basis for the insulation calculation. Table 3. 1. 4
High point temperature
Below-30
. 30 ~- 15
Above-15
Allowable heat loss
Insulation pressure 6 (barrel)
Allowable heat loss, m/(m·h)
39 × 4. 1868
33 x4.1868
2R ×4.1868
34 × 4. 1868
29 ×4. 1868
26 ×4. 1868
The heat loss of each heat preservation box is 500x4.1868kJ/h. 30×4,1868
27 ×4. 1568
The allowable heat loss of hot water tracing is 500x4.1868kJ/h. According to different atmospheric temperatures, the steam pressure of 0.3MPa in Table 3.1.4 can be selected accordingly.
The thickness of the steam tracing insulation layer can also be set according to the atmospheric temperature according to the values ​​in Table 3.1. Without calculation, the approximate thickness of the insulation can be directly selected.
Atmospheric temperature, ℃
Below -30
- 30 - - 15
- 15 Above
Table 3. 1. 7
Moisture retardant layer thickness selection table
Steam pressure, MPa
Insulation layer thickness, m
Note: The insulation layer thickness in Table 3.1.7 is calculated when the full humidity in the measuring line is 60%. 3.1.8 The thickness of the hot water heating insulation layer shall be selected according to Table 3.1.7. When the atmospheric temperature is as high as -5C, insulation can be used by adiabatic method, and the insulation degree can be calculated by formula (3.1.1) or determined as 10mml. The medium with a higher freezing point in this environment shall be heated and insulated. 3.1.9 The thickness of the electric heating insulation layer shall be selected according to Table 3.1.7. 3.2
Calculation of insulation steam and hot water consumption
Formula:
The total heat loss of the system is the sum of the heat loss of each insulation line of the entire installation, and its value should be 5
Qs—total heat loss, kJ/h;
g: x Li+ Qu)
L——insulation length of the first insulation line, m; QThe heat loss of the first insulation box, kJ/h:
i—number of insulation systems, i-1, 2, 3nn3.2.2 Steam consumption is calculated by the following formula: m=
Total steam consumption for instrument insulation, kg/h:
K——ratio coefficient;
(3. 2. 1)
H Latent heat of vaporization of steam, kJ/kB
In actual operation, the following unavoidable factors should be considered, taking E, = 2 as the basis for determining the steam main pipe: 1 Fluctuation of the general steam network pressure;
The reduction of the insulation effect of the warm layer after years of use; 3
Make sure to allow for pressure loss:
Heat loss of pipe fittings;
Steam leakage caused by steam trap:
Hot water consumption V should be calculated as follows:
V= K C.(nt).p
In the formula, total consumption of hot water for instrument insulation, m/h--temperature of hot water for insulation pipeline, C:
t--return water temperature, C:
p--density of hot water, kg/m;
C--specific heat of water (take 4.1868kJ/kg: ℃): K,--data consumption coefficient i includes heat absorption and leakage absorption), generally take K,=1.05. (3. 2. 3)
temperature of hot water for insulation pipeline. And return water temperature t are related to the characteristics of the medium in the instrument pipeline (such as polymerization, strong thermal properties, decomposition, etc.).
The hot water pressure is generally considered to be able to return to the water main. 284
4 Design of the heating system
4.1 Steam heating system
4.1.1 An independent steam supply system should be set up for the steam used for instrument heating. For a few separate instrument insulation objects, steam can be supplied according to specific conditions
4.1.2 The steam heating system includes the main pipe, branch pipe (or steam distribution curtain), accompanying pipe and pipe accessories. The connection between the main pipe, branch pipe or steam distributor and accompanying pipe should be welded, and the connection point should be at the top of the steam pipe. 4.1.3 The root of the steam pipe and the branch pipe should be installed. See Figure 4.1.3. 4.1.4 A water controller should be installed at the bottom of the steam main pipe. In special cases, the return water pipe should be heated. 4.1.3 Steam insulation block pipeline density
In the figure: 1-steam main pipe: 2-steam branch pipe: 3 steam tracing pipe: 4-insulation culvert: 5 steam trap 6---condensate pipe: 1-return water branch pipe; 8-return water main pipe, 4.2 Selection of steam traps
4.21 Each Taiqi heat tracing and insulation system should be equipped with a separate condensate trap. 4.22 The steam trap for instrument insulation should be safe and reliable, easy to install, and it is appropriate to use a commercial steam trap with a filter and a check function.
4.2.3 The calculation result of formula (3.2.2), that is, the steam consumption point for instrument insulation, is used as the basis for calculating the diameter of the steam trap.
mb=K+m
The design tank water volume of the steam trap, kg/h:
K—the utilization rate of the steam trap. Considering the safety factor and the use factor comprehensively, K=3 is set. 4.3 Selection of accompanying pipes
(4. 2. 3)
Steam accompanying pipes should be made of stainless steel pipes or copper pipes. If conditions permit, stainless steel +.3.1
The base pipe diameter can be selected according to Table 4.3.
Table 4.3.1
Materials for steam tracing
Stainless steel pipe
Stainless steel copper pipe
Stainless steel pipe
Stainless steel
Materials and specifications for tracing pipes
Parts pipe specification
d8×1
10×1(10×1.5)
414×2(±18×3)
Selection of main pipe and branch pipes
Steam tracing main pipe and branch pipes are made of non-chain steel pipes. The steam consumption calculated according to formula (3.2.2) can be used as the basis for selecting the inner diameter of the pipeline. The corresponding main pipe or branch pipe diameter can be selected according to the main pipe or branch pipe flow control table 4.4.1.
Pipe specifications
0.07-0.13
1 0. 13 ~ 0. 34
0. 34 - 0. 64
0. 64 - 1. 9
1. 9 ~ 3. 8
Relationship between steam volume, flow rate and pipe diameter. Steam pressure. M
Flow rate
Steam volume m
5. 05 - 0. 1
0.1 ~0.26
0. 7.6 - 0. 5
0.5 - 1. 4
1. 4 ~ 2. 7
Steam volume indication
0. 03 ~0. 06
The maximum number of heat tracing and insulation points of the pipeline can be selected according to Table 4.4.2. Table 4.4.2
Pipeline specifications
422 × 2.5
$27 x 2.5
City 34 x 2.5
City 4×3
089 ×3.5
Number of insulation points
Steam pressure, MP
Number of insulation points
Cold avoidance, selection of cooling return pipe
The return system should be considered according to the following basic requirements: The condensation volume of each return pipeline is roughly equal: The pressure loss of each return system should be as small as possible: 2
The resistance between each parallel return system is roughly the same: 0.06 0.16
0.16 ~0.3
Generally speaking, the centralized water return method should be adopted, that is, no condensation and cooling water return main pipe is installed, and the condensation and cooling22 The water collector for instrument insulation should be safe, reliable and easy to install. It is suitable to adopt a commercial water collector with a filter and a check function.
4.2.3 The calculation result of formula (3.2.2) is the steam consumption point for instrument insulation, which is used as the basis for calculating the diameter of the steam trap.
mb=K+m
The design tank water volume of the steam trap, kg/h:
K-the use rate of the steam trap, comprehensively considering the safety factor and the use factor, set K=3. 4.3 Selection of accompanying pipes
(4. 2. 3)
Steam accompanying pipes should be made of stainless steel pipes or copper pipes. If conditions permit, stainless steel +.3.1
The pipe base diameter can be selected according to Table 4.3.
Table 4.3.1
Materials for steam tracing
Stainless steel pipe
Stainless steel copper pipe
Stainless steel pipe
Stainless steel
Materials and specifications for tracing pipes
Parts pipe specification
d8×1
10×1(10×1.5)
414×2(±18×3)
Selection of main pipe and branch pipes
Steam tracing main pipe and branch pipes are made of non-chain steel pipes. The steam consumption calculated according to formula (3.2.2) can be used as the basis for selecting the inner diameter of the pipeline. The corresponding main pipe or branch pipe diameter can be selected according to the main pipe or branch pipe flow control table 4.4.1.
Pipe specifications
0.07-0.13
1 0. 13 ~ 0. 34
0. 34 - 0. 64
0. 64 - 1. 9
1. 9 ~ 3. 8
Relationship between steam volume, flow rate and pipe diameter. Steam pressure. M
Flow rate
Steam volume m
5. 05 - 0. 1
0.1 ~0.26
0. 7.6 - 0. 5
0.5 - 1. 4
1. 4 ~ 2. 7
Steam volume indication
0. 03 ~0. 06
The maximum number of heat tracing and insulation points of the pipeline can be selected according to Table 4.4.2. Table 4.4.2
Pipeline specifications
422 × 2.5
$27 x 2.5
City 34 x 2.5
City 4×3
089 ×3.5
Number of insulation points
Steam pressure, MP
Number of insulation points
Cold avoidance, selection of cooling return pipe
The return system should be considered according to the following basic requirements: The condensation volume of each return pipeline is roughly equal: The pressure loss of each return system should be as small as possible: 2
The resistance between each parallel return system is roughly the same: 0.06 0.16
0.16 ~0.3
Generally speaking, the centralized water return method should be adopted, that is, no condensation and cooling water return main pipe is installed, and the condensation and cooling22 The water collector for instrument insulation should be safe and reliable, easy to install, and it is appropriate to adopt a commercial water collector with a filter and a check function.
4.2.3 The calculation result of formula (3.2.2), that is, the steam consumption point for instrument insulation, is used as the basis for calculating the diameter of the steam trap.
mb=K+m
The design tank water volume of the steam trap, kg/h:
K-the use rate of the steam trap, comprehensively considering the safety factor and the use factor, set K=3. 4.3 Selection of accompanying pipes
(4. 2. 3)
Steam accompanying pipes should be made of stainless steel pipes or copper pipes. If conditions permit, stainless steel +.3.1
The pipe base diameter can be selected according to Table 4.3.
Table 4.3.1
Materials for steam tracing
Stainless steel pipe
Stainless steel copper pipe
Stainless steel pipe
Stainless steel
Materials and specifications for tracing pipes
Parts pipe specification
d8×1
10×1(10×1.5)
414×2(±18×3)
Selection of main pipe and branch pipes
Steam tracing main pipe and branch pipes are made of non-chain steel pipes. The steam consumption calculated according to formula (3.2.2) can be used as the basis for selecting the inner diameter of the pipeline. The corresponding main pipe or branch pipe diameter can be selected according to the main pipe or branch pipe flow control table 4.4.1.
Pipe specifications
0.07-0.13
1 0. 13 ~ 0. 34
0. 34 - 0. 64
0. 64 - 1. 9
1. 9 ~ 3. 8
Relationship between steam volume, flow rate and pipe diameter. Steam pressure. M
Flow rate
Steam volume m
5. 05 - 0. 1
0.1 ~0.26
0. 7.6 - 0. 5
0.5 - 1. 4
1. 4 ~ 2. 7
Steam volume indication
0. 03 ~0. 06
The maximum number of heat tracing and insulation points of the pipeline can be selected according to Table 4.4.2. Table 4.4.2
Pipeline specifications
422 × 2.5
$27 x 2.5
City 34 x 2.5
City 4×3
089 ×3.5
Number of insulation points
Steam pressure, MP
Number of insulation points
Cold avoidance, selection of cooling return pipe
The return system should be considered according to the following basic requirements: The condensation volume of each return pipeline is roughly equal: The pressure loss of each return system should be as small as possible: 2
The resistance between each parallel return system is roughly the same: 0.06 0.16
0.16 ~0.3
Generally speaking, the centralized water return method should be adopted, that is, no condensation and cooling water return main pipe is installed, and the condensation and cooling
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