JB/T 5902-2001 Oxygen pipeline technology for air separation equipment
Some standard content:
ICS71.100.20
J76
JB
Mechanical Industry Standard of the People's Republic of China
JB/T5902-2001
Oxygen pipelines for air separation equipment||tt ||Technical conditions
Technical conditions for oxygen pipelinesusedinairseparationplants
Released on 2001-05-23
China Machinery Industry Federation
Released
2001-10- 01Implementation
JB/T5902-2001
Foreword
This standard is a revision of JB/T5902-1992 "Technical Conditions for Oxygen Pipelines for Air Separation Equipment". Compared with JB/T59021992, the main technical content of this standard has changed as follows: 1. In Table 4, the original valve "within 1.5m area: within 1.5m area before and after the regulating valve (or distribution valve) group:" is changed to "behind the valve" Within the area of ??5 times the outer diameter (not less than 1.5m); within the area of ??5 times the outer diameter (not less than 1.5m) before and after the regulating valve (or distribution valve) group: \Change 4.3.2.1 to "Oxygen pipelines are strictly prohibited to use wrinkles elbow. When cold-forming or hot-bending carbon steel elbows are used, the bending radius should not be less than 5 times the outer diameter of the pipe; when seamless or press-welded carbon steel elbows are used, the bending radius should not be less than 1.5 times the outer diameter of the pipe. times; when using stainless steel or copper-based alloy seamless or pressed elbows, the bending radius should not be less than the outer diameter of the pipe. For steel plate coiled welded pipes with a working pressure not greater than 0.1MPa, a welded elbow with a bending radius not less than 1.5 times the outer diameter of the pipe can be used. The inner wall of the elbow should be smooth and free of sharp edges, burrs and welding burrs.
Cancel Article 4.3.2.3.
- Modify Article 4.3.4.1 to read "The reducing pipe of the oxygen pipeline should be made of seamless or pressed welding parts. When welded, the length of the reducing part should not be less than 3 times the difference in the outer diameter of the two ends of the pipe. times. The inner surface should be smooth and free of sharp edges, burrs and welding burrs. Add 5.11.4.
Add "Oxygen pipelines should have anti-static grounding measures" in 6.11. Remove Article 7. Chapter, Operation and Maintenance Technical Requirements. First, Chapter 8 is changed to Chapter 7, and the standards for radiographic inspection are modified. Steel and aluminum pipe welds comply with the JB4730 standard, and copper welds comply with the JB/T7260 standard. And the inspection ratio has been modified. - Appendix A and Appendix B have been cancelled.
This standard replaces JB/T5902-1992 from the date of implementation. This standard was proposed by the Mechanical Industry Gas Separation and Liquefaction Equipment Standardization Technical Committee. This standard was drafted by: Hangzhou Oxygen Concentrator Group Co., Ltd. The main drafters of this standard were: Ding Hongliang and Peng Zhenkang. This is the first revision of this standard. ||Machinery Industry Standards of the People's Republic of China
Oxygen pipelines for air separation equipment
Technical conditions
Teehnical conditions for oxygen pipelines used in air separation plantsJB/T5902—2001
Replaced JB/T5902—1992
This standard specifies the design and manufacture of pipelines (including straight pipes, pipeline accessories and valves) used to transport oxygen (purity greater than or equal to 90%) in air separation equipment (referred to as air separation equipment) , installation technical requirements, inspection and test methods and packaging, etc. This standard is applicable to oxygen-rich air (oxygen content greater than 21%) pipelines that are completed by the manufacturer or provided with semi-finished products on site. This standard can be followed. It does not apply to pressure pipes filled with gas cylinders and oxygen pipes designed and manufactured by users or engineering design units. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard by being quoted in this standard. The versions shown are valid when the standard is published. All standards will be revised and parties using this standard should explore the possibility of using the latest version of the following standards. JB/T6896—1993
JB/T7260—1994
3 General provisions
Steel pressure vessels
No damage to pressure vessels
Air separation equipment Surface cleanliness
Radiography and quality classification of copper welds of air separation equipment 3.1 If the user has special requirements, it shall be stipulated in the contract, but it shall not be lower than the requirements of this standard. 3.2 Oxygen pipelines are special pipelines and must be used in any case. Avoid conditions that lead to the combination of igniters, combustibles and oxidants. 4 Design
4.1 The strength calculation of pipelines and flanges shall be based on the relevant provisions of GB150 and "Pressure Vessel Safety Technical Supervision Regulations", and flanges may also be calculated according to corresponding standards. Select. bzxZ.net
4.2 Pipeline flow rate
4.2.1 The flow rate is a uniform continuous flow rate and should be calculated based on the maximum flow rate at the lowest working pressure. 4.2.2 The allowable maximum flow rate of austenitic stainless steel, copper, and aluminum alloy pipelines at normal temperature is specified in Table 1, and at low temperature is specified in Table 2. The allowable maximum flow rate of carbon steel pipelines at normal temperature is specified in Table 3. China Machinery Industry Federation approved the implementation on 2001-10-01 on 2001-05-23
4.2.3
Working pressure MPa
0.1
>0.1-3|| tt||>3
Working pressure MPa
0.1-0.16
0.5-0.7
Working pressure MPa
0.1
>0.1 -3
JB/T5902—2001
Table
Table 2
Table 3
Maximum allowed flow rate
25||tt| |15
8
mV/s
Maximum flow rate allowed m/s
15
8
Maximum flow rate allowed||tt ||m/s
25
15
The pipeline flow rate should also meet the requirements of limiting resistance loss, pressure pulsation and other special requirements of the unit. Materials and shapes of straight pipes and pipe accessories
4.3
4.3.1 The material selection for the straight pipe part shall be in accordance with Table 4 or relevant standards. Carbon steel pipes cannot be used for directly buried pipes. Table 4
Conditions of use
Working pressure
MPa
50.6
>0.6~1.6
>1.6~3||tt| |>3
Note:
2
One stock exchange
Pipeline in the tower
Use
Place
Read Door frequency alarm is activated
General places
In the area of ??5 times the outer diameter (not less than 1.5m) behind the valve: 5 times the outer diameter (not less than 1.5m) before and after the regulating cabinet (or distribution width) group ) area: indoor piping in the fluorine press workshop
general places
within the area of ??5 times the outer diameter (not less than 1.5m); 5 chromium outer diameters at the front and rear of the adjustment width (or distribution valve) group (not less than 1.5m) area: pressure vessel connection; all places of indoor piping in the compressed oxygen workshop
"×" means not used. "V" means available. Pot welded pipe
x
x
x
should use
pipe
seamless steel pipe
★|| tt||x
stainless steel pipe
v
V
V
V
V
V||tt ||v
steel alloy pipe
v
V
V
V
v
V||tt ||Aluminum alloy pipe
V
V
V
x
4.3.2 Elbow
JB/T5902-2001| |tt||4.3.2.1 Oxygen pipelines are strictly prohibited from using corrugated elbows. When using cold or hot bending to make elbows, the bending radius should not be less than 5 times the outer diameter of the pipe; when using seamless or press-welded carbon steel elbows, the bending radius should not be less than 1.5 times the outer diameter of the pipe; When using stainless steel or copper-based alloy seamless or pressed elbows, the bending radius should not be less than the outer diameter of the pipe. For steel plate coiled welded pipes with working pressure not greater than 0.1MPa, welded elbows with a bending radius not less than 1.5 times the outer diameter of the pipe can be used. The inner wall of the elbow should be smooth and free of sharp edges, burrs and welding burrs. 4.3.2.2. The elbow material should generally be the same as that of straight pipes, but when the working pressure is greater than 1MPa, stainless steel or copper elbows must be used. 4.3.3 Tee pieces
4.3.3.1 Oxygen pipelines should have as few tee pieces as possible. 4.3.3.2 Tee parts should be made of stainless steel or steel, aluminum alloy and other materials that are not easily flammable. 4.3.3.3 The direction of the air flow at the bifurcation part should not be at right angles to the main pipe wall, generally at an angle of 45°~60°. 4.3.4 Reducing pipes (including exhaust pipes, purge pipes, pressure relief pipes) The reducing pipes of oxygen pipelines should be made of seamless or pressed welding parts. When welded, the length of the reducing part should not be less than 3 times the difference in the outer diameter of the two ends 4.3.4.1
. The inner wall should be smooth and free of sharp edges, burrs and welding burrs. 4.3.4.2 The reducing pipe should generally be made of copper or stainless steel pipes, and the dividing and increasing tower system can be made of aluminum alloy pipes. 4.3.5 Sealing gaskets must meet the requirements of flange strength level. Asbestos rubber gaskets can be used for flange seals with working pressures not greater than 0.6MPa: flange seals with working pressures greater than 0.6MPa should be made of annealed and softened aluminum or Copper gasket, wound stainless steel gasket, PTFE gasket.
4.4 Selection and setting of valves
4.4.1 Types of valves
4.4.1.1 The cut-off valves in oxygen pipelines should use rising stem stop valves, ball valves and media valves. It is strictly prohibited Use a gate valve. 4.4.1.2 Pneumatic automatic or remote control valves should be used for belt-operated oxygen valves. The shut-off valve at the outlet of the oxygen compressor should be an electric or pneumatic valve that closes slowly (30-60s). 4.4.1.33
The required caliber of the regulating valve must be selected according to the calculated flow coefficient value. Single-seat, double-4.4.1.41
-seat or sleeve-type regulating valve shall be selected according to the working pressure and regulation requirements. The regulating valve can also be used when the working pressure is less than or equal to 1MPa. 4.4.1.5 The oxygen compressor outlet check valve should be a check valve with a seat buffer device. The check valve should have an arrow mark indicating the correct flow direction.
4.4.1.6 The safety valve on the oxygen pipeline should be a full-open safety valve. 4.4.2 The selection of valve materials shall be as specified in Table 5. Table 5
Working pressure
MPa
≤0.6
>0.6~10
>10
Note
Material
Materials
The valve body and cover are made of silver cast iron, ductile steel: the rod is made of carbon steel or stainless steel: the valve is made of stainless steel, all stainless steel, all steel-based alloy or a combination of stainless steel and steel-based alloy (Steel-based alloys are preferred) Use all-copper-based alloys
1 materials with a working pressure of 0.1MPa or above for pressure or flow regulation. Stainless steel or copper-based alloys or a combination of the above two should be used. 2. The sealing packing of the door should be made of stone-covered asbestos or polytetrachlorethylene material or shadow stone. JB/T5902-2001
4.4.3 Inflammable materials shall not be used for the packing of the oxygen door. 4.4.4 Setting and installation of the valve
4.4.4.1 There should be no oil on the valve stem and other movable parts. The internal parts of the valve and the inner surface of the valve body must be thoroughly degreased and cleaned, and the amount of grease residue must not exceed 125mg/m .
4.4.4.2 For valves with a transmission device, the transmission device should have good sealing, and the grease used in the transmission device should be non-flammable. 4.4.4.3 For carbon steel pipes, there should be a straight pipe of more than 1.5m before and after the pipe, and the materials should be selected according to Table 4. 4.4.4.4 In carbon steel pipelines, a filter should be added in front of the regulating valve (upstream side) and the filter should be cleaned regularly. 4.4.4.5
The assembly and testing of valves shall be carried out in accordance with relevant standards and technical documents. 5 Manufacturing
The materials used to manufacture pipelines should comply with relevant standards. The outer surface of the pipe is clearly marked with the material grade. 5.1 | 5.3 The end faces and welding grooves of steel pipes should be mechanically cut and burrs should be removed. 5.4 The perpendicularity between the cut plane of the straight pipe and the axis of the straight pipe shall not be greater than 1% of the pipe diameter and shall not be greater than 3mm. 5.5 The groove of the butt weld shall be as specified in the drawing or process document. 5.6 The bending deviation of straight pipe 4 (see Figure 1) is ±3mm/m starting from the bending intersection point. When the straight pipe length is greater than 3m, the total deviation is ±10mm.
Picture!
5.7 There should be no obvious wrinkles or unevenness on the surface of the elbow. 5.8 The pipe can be bent by hot bending or cold bending, but the red sand hot bending method is not allowed. The residue and oxides in the pipe should be completely removed after other hot bending methods are formed.
5.9 The wall thickness reduction of the elbow part shall not be greater than 12.5% ??of the nominal wall thickness, and the absolute value shall be less than 0.5mm. 5.10 Hot-processed or cold-stamped elbows and reducers shall not have defects such as cracks or overburning, and the manufacturing accuracy shall be as specified in Table 6. Table 6
Types of pipe fittings
Raising slope
increasing slope
structural length
knot length garden
inspection items|| tt||Outer diameter deviation
Inner diameter deviation
Outer diameter deviation
Wall thickness deviation
Structural length deviation
Duanren deviation||tt| |25-80
± 1.0
Nominal diameter D%
>80~100
±1.5
+1.5
0| |tt||+1.0
0
>100~200
±2.0
<12.5%
42.5
0|| tt||+1.5
0
>200-400
±3.5
5.11 butt welding
JB/T 5902—2001||tt| |5.11.1 The butt joints of pipe fittings should be coaxial, and the wall thickness misalignment tolerance is: a) When D% ≤ 100mm, it is required to be less than 10% of the pipe wall thickness: b) When D> 100mm, it is required to be less than 10% of the total pipe thickness + 0.3, and shall not be larger than 1.5mm; c) When pipes or elbows with the same nominal diameter but different actual outer diameters or inner diameters are misaligned and cannot meet the above requirements, the inner or outer walls of the ends are allowed to be ground at a slope of less than 14° to make them The wall thickness misalignment tolerance can meet the requirements of 5.11.1a) or b). 5.11.2 The weld reinforcement inside the pipe should be less than 3mm. 5.11.3 Village rings shall not be used on the inner wall of stainless steel pipes. When the diameter of aluminum alloy pipes is greater than 80mm, embedded rings may be used. 5.11.4 Butt welds should be primed by argon arc welding. 5.12 Fillet weld
5.12.1 The height of the fillet weld between the outer wall of the pipe and the flange is generally 0.7~1 times the pipe wall thickness, but shall not be greater than 16mm; the height of the fillet weld between the inner wall of the pipe and the flange is 0.7 to 1 times the pipe wall thickness. Overall thickness, but not greater than 6mm. 5.12.2 Hydrogen arc welding should be used for the internal fillet welds between the steel pipe wall and the flange to prevent spatter from sticking to the pipe wall. 5.13 Welds should be marked with the welder’s mark.
5.14 Arcing outside the welding area is not allowed. 5.15 The environmental conditions and requirements for pipeline welding should comply with the relevant regulations of GB150. 5.16 After the manufactured oxygen pipeline components pass the hydrostatic test, they must be degreased and comply with the provisions of 7.3. 6 Installation technical requirements
6.1 When installing the oxygen pipeline, the cleanliness and grease residue must be re-checked. If it is unqualified, degreasing and cleaning should be performed again and the inspection must be qualified. 6.2 The gasket must be accurately made and of appropriate size. No loose material or cracked edges are allowed to enter the oxygen zone. The gasket must be placed correctly in the joint position, not protruding into the air flow area, and must be completely tight to prevent gas from crossing the joint surface. 6.3 Various oxygen valves must have factory certificates, and the air tightness test should be re-tested before installation. 6.4 The pipelines produced on site shall comply with the provisions of 5.15 and comply with the drawing requirements. 6.5 If the pipes produced on site are rusted, they must be derusted first. After welding, the welding slag, spatter, etc. in the pipe must be removed and degreased.
6.6 Carbon steel pipes prefabricated by the manufacturer are allowed to be reheated for slight correction. Pipes made of non-ferrous metals or stainless steel must not be heated and corrected without the consent of the manufacturer.
6.7 Mark the material grade on the pipe.
6.8 The deviation of assembly dimensions shall not exceed the following requirements (see Figure 2) a) The total length deviation 4L in each direction is ±5mm; b) The spacing deviation △N is ±3mm;
c) Pipe The maximum displacement e of the end is ±0.8mm;
d) The maximum displacement c of the branch pipe or nozzle is ±1.6mm; e) The maximum tolerance of the flange rotation displacement f is △f=f-=±lmm. 6.9. After the pipeline is installed, it should be blown out step by step. Particular attention should be paid to using the pipe, orifice flowmeter, filter and the upstream side pipe end of the container as the outlet for the staged blowing (discharged to the outside of the system) to prevent blowing. The debris that comes out is blown into the dead corners or damaged parts of valves, containers and other components: JB/T5902-2001
The blowing gas should be oil-free dry air or nitrogen, and the blowing should be thorough until there is no rust, dust or In addition to other dirt, the blowing speed should be greater than 20m/s.
V+7
+
6.10 It is strictly forbidden to use oxygen to blow the pipelines.
YVA
NV+N
N+N
Figure 2
6.11 Oxygen pipelines should have anti-static grounding measures, and each section of the pipeline should be conductive Good. When the total resistance value between each pair of flanges or threaded joints exceeds 0.03, there should be a wire jumper.
7 Inspection and test methods
7.1 Weld inspection
7.1.1 Appearance inspection
7.1.1.1 Welds shall not have undercuts, nodules, pits, Defects such as cracks, surface pores, splashing slag and dents. 7.1.1.2 The rust, spattered slag and welding slag on the inner wall of the pipeline must be removed and the weld penetration and weld reinforcement must be checked. 7.1.2 Radiographic inspection
7.1.2.1 The longitudinal welds of pipelines (including T-weld intersections) must be 100% radiographic inspected. The welds of steel and aluminum pipelines shall comply with Level II specified in JB4730; copper welds Should comply with Level II specified in JB/T7260. 7.1.2.2 The radiographic inspection ratio of girth welds shall be as specified in Table 7. Steel and aluminum welds shall comply with the Level III standards specified in JB4730, and the copper welds shall comply with the Level II standards specified in JB/T7260. When welding pipe girth welds with D ≤ 80 mm in the manufacturer, the radiographic inspection ratio is to randomly inspect the welds welded by each welder according to the proportion of welding joints. The minimum number of spot inspections on each pipeline shall not be less than 1 welding joint. 6
Pipe material
Steel welded pipe
Seamless steel pipe
Stainless steel pipe
Aluminum alloy pipe
Steel, steel alloy pipe| |tt||JB/T5902-2001
Table 7
Working pressure MPa
≤0.6
≤1.6
≤1.6
>1.6
≤0.6
>0.6
≤0.6
>0.6~1.6
>1.6
Check ratio||tt| |≥20%
≥20%
>20%
100%
≥20%
100%
>20%
40%
100%
Note: The inspection ratio listed in the table is the percentage of the weld length welded by each welder: for D, ≤80mm pipes, the inspection ratio Percentage of joints welded by each welder, but all inspected welds must be inspected for flaw detection. 7.1.2.3 Weld parts that fail to pass the inspection should be re-welded with the defects removed and re-inspected. The number of re-welds should not exceed two times. Repairs exceeding two times should be approved by the person in charge of manufacturing technology. 7.1.2.4 If any unqualified welder is found, the welds of the randomly inspected welders should be double inspected according to the original specified proportion. If still unqualified, conduct radiographic inspection of all welds of the welder.
7.1.2.5 The welds of pipes subject to air pressure testing shall be 100% radiographic inspected. 7.2 Pressure resistance test and leakage rate test
7.2.1 For those pipelines that need to be welded and adjusted on site, the pressure resistance test and leakage test shall be carried out after the on-site production is completed. 7.2.2 The welded oxygen pipeline should be subjected to a strength test. The test medium should be oil-free clean water, nitrogen or air. The test pressure and requirements should be in accordance with the relevant regulations of GB150.
7.2.3 After the oxygen pipeline system is installed and purged successfully, a leakage rate test should be conducted. The test gas must be oil-free dry media nitrogen or oil-free dry air. The pressure for the leakage rate test is the working pressure. After maintaining pressure for 24 hours, check the average leakage rate per hour. The leakage rate 4 is calculated according to formula (1):
(273+t)p
(273+t,)p,
where: A - average hourly leakage rate , %P, P
- the pressure at the beginning and end of the pressure test, MPa; , - the temperature at the beginning and end of the pressure test, ℃. 7.2.4 Leakage rate requirements
100
24
When D%≤300mm, the average leakage rate per hour shall not be greater than 0.25%. When D%>300mm, the average leakage per hour The rate shall not be greater than 0.25×(300/D)%. 7.2.5 The leakage test and requirements of the piping system in the cold box shall be in accordance with the technical specifications and technical documents for the installation of air separation equipment. 7.3 Degreasing inspection
(1)
Oxygen pipelines must be degreased. The amount of oil and grease residue on the surface of the pipe in contact with oxygen and the inspection method shall comply with the relevant regulations of JB/T6896.
7
2. The welded oxygen pipeline should be subjected to strength test. The test medium should be oil-free clean water, nitrogen or air. The test pressure and requirements should be in accordance with the relevant regulations of GB150.
7.2.3 After the oxygen pipeline system is installed and purged successfully, a leakage rate test should be conducted. The test gas must be oil-free dry media nitrogen or oil-free dry air. The pressure for the leakage rate test is the working pressure. After maintaining pressure for 24 hours, check the average leakage rate per hour. The leakage rate 4 is calculated according to formula (1):
(273+t)p
(273+t,)p,
where: A - average hourly leakage rate , %P, P
- the pressure at the beginning and end of the pressure test, MPa; , - the temperature at the beginning and end of the pressure test, ℃. 7.2.4 Leakage rate requirements
100
24
When D%≤300mm, the average leakage rate per hour shall not be greater than 0.25%. When D%>300mm, the average leakage per hour The rate shall not be greater than 0.25×(300/D)%. 7.2.5 The leakage test and requirements of the piping system in the cold box shall be in accordance with the technical specifications and technical documents for the installation of air separation equipment. 7.3 Degreasing inspection
(1)
Oxygen pipelines must be degreased. The amount of oil and grease residue on the surface of the pipe in contact with oxygen and the inspection method shall comply with the relevant regulations of JB/T6896.
7
2. The welded oxygen pipeline should be subjected to strength test. The test medium should be oil-free clean water, nitrogen or air. The test pressure and requirements should be in accordance with the relevant regulations of GB150.
7.2.3 After the oxygen pipeline system is installed and purged successfully, a leakage rate test should be conducted. The test gas must be oil-free dry media nitrogen or oil-free dry air. The pressure for the leakage rate test is the working pressure. After maintaining pressure for 24 hours, check the average leakage rate per hour. The leakage rate 4 is calculated according to formula (1):
(273+t)p
(273+t,)p,
where: A - average hourly leakage rate , %P, P
- the pressure at the beginning and end of the pressure test, MPa; , - the temperature at the beginning and end of the pressure test, ℃. 7.2.4 Leakage rate requirements
100
24
When D%≤300mm, the average leakage rate per hour shall not be greater than 0.25%. When D%>300mm, the average leakage per hour The rate shall not be greater than 0.25×(300/D)%. 7.2.5 The leakage test and requirements of the piping system in the cold box shall be in accordance with the technical specifications and technical documents for the installation of air separation equipment. 7.3 Degreasing inspection
(1)
Oxygen pipelines must be degreased. The amount of oil and grease residue on the surface of the pipe in contact with oxygen and the inspection method shall comply with the relevant regulations of JB/T6896.
7
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