Some standard content:
Mechanical Industry Standard of the People's Republic of China
Heat exchange tubes for Freon condensation
1 Subject content and scope of application
JB/T 7226 94
This standard specifies the type, basic parameters, technical requirements, packaging, marking and other requirements of heat exchange tubes for Freon water-cooled condensation. This standard applies to heat exchange tubes for Freon vapor water-cooled condensation in refrigeration, air conditioning and other industries (hereinafter referred to as heat exchange tubes). 2 Reference standards
GB1527 Drawn copper tubes
Processed copper chemical composition and product shape
GB5231
GB5234 Processed white copper chemical composition and product shape GB8890 Copper alloy tubes for heat exchangers
3 Terms and symbols
3.1 Terms
3.1.1 Heat exchange tubes
Components that transfer heat in condenser products. One side of the wall is in contact with the fluorine vapor, and the other side is in contact with cooling water (fresh water or sea water).
3.1.2 Bare tube
That is, a smooth tube, which can be directly used as a heat exchange tube, and is also a bad tube for processing various enhanced heat exchange tubes. 3.1.3 Low-fin tubebzxz.net
Using a special processing method, the outer surface is processed into a threaded wing shape to expand the surface area of the enhanced heat exchange tube, also known as a threaded low-assisted tube,
3.1.4 Type A high-efficiency tube
Using a special processing method, the outer surface of the bare tube is processed into a saw-wing thread shape, which greatly improves the condensation effect.
3.1.5 Type B high-efficiency tube
Using a special processing method, the outer surface of the bare tube is processed into a saw-wing thread shape with a screw groove, which not only greatly improves the condensation effect, but also enhances the heat transfer in the tube. 3.2 Symbols
Length of heat exchange tube, mm;
Pitch of heat exchange tube thread wing, mm;
Pitch of heat exchange tube screw groove, mm:
h, - Wing height of heat exchange tube thread wing, mm; h
Inner convex height of heat exchange tube screw groove, mm;
d - Outer diameter of heat exchange tube, mm;
- Outer diameter of heat exchange tube thread wing, mm; Approved by the Ministry of Machinery Industry on July 18, 1994
Implementation on July 1, 1995
Wall thickness of heat exchange tube, mm;
o. Wing thickness of heat exchange tube thread wing, mm;
t. Wing tip height of heat exchange tube serrated wing, mm.
4 Types and basic parameters
4.1 Types and codes of heat exchange tubes
a. Bare tubes for condensation, NG;
Low-fin tubes for condensation, ND;
Type A high-efficiency tubes for condensation, NJA;
Type B high-efficiency tubes for condensation, NJB.
4.2 Basic parameters of heat exchange tubes
4.2.1 Basic parameters of heat exchange tubes shall be in accordance with the provisions of Table 1. Heat exchange tube category
Bright tube NG
Low fin tube NI)
Type A high efficiency tube NJA
Type B high efficiency tube NJB
Outer diameter station
12～19
JB/T 7226 --- 94
0.5,0.75,1.0,1.2,1.5
1.0.1.2,1.5,2.0
1.0,1.2,1.5,2.0
4.2.2 The dimensions of the low fin tube shall be in accordance with the requirements of Figure 1 and Table 2. Figure 1
300~8 000
300~~8 000
300~8 000
300-8 000
Broken tube outer diameter d
Warp height h
Fin outer diameter dr
JB/T7226-94
4.2.3The dimensions of type A high efficiency tubes shall comply with the provisions of Figure 2 and Table 3. uu
rinnhfnnrnnhhn佳
Tube outer diameter d
Also tube outer diameter d
Fin height hl
[Broken tube outer diameter d
Fin tip height:
Fin outer diameter d
4.2.4The dimensions of type B high efficiency tubes shall comply with the provisions of Figure 3 and Table 4. 16
Wing pitch milk
Wing pitch 6
Warp height h
Wing outer diameter r
Wing tip height (
Wing thickness 8
Fan outer diameter
Bone outer diameter d
4.3Heat exchange area
JB/T 7226—94
Znhhnr
Wing height h
Wing tip height t
The heat exchange area of each meter of heat exchange tube is specified as the outer surface area of the tube 4, that is: A = d × 10-3
Pitch sand
Inner height:
Wing outer diameter
4.4Heat exchange tube model
JB/T 7226.-- 94
Heat exchange tube model consists of capital Chinese pinyin letters and Arabic numerals, and the representation method is as follows: X
Model example:
Heat exchange tube fin height.mm
Heat exchange tube fin pitch.mm
Heat exchange tube broken tube wall thickness, mm
Heat exchange tube broken tube outer diameter, nm
Heat exchange tube category code (according to Article 4.1) NIA16×1.2--1.0×1.) indicates A-type high-efficiency tube for condensation, broken tube outer diameter 16mm. Wall thickness 1.2mm. Fin pitch 1.0nm. Warp height 1.0 mm.
5 Technical requirements
5.1 Heat exchange tubes shall comply with the requirements of this standard and be manufactured according to drawings and technical documents approved by the prescribed procedures. 5.2 Heat exchange tube materials shall adopt the grades and states specified in Table 5. If other grades of heat exchange tubes are ordered, trial production shall be negotiated with the supplier. The chemical composition of the heat exchange tube material shall comply with the requirements of GB5231 and GB5234. 5
Heat exchange tube brand
T2.TP2,TU2.HSn70-1.HA177-2
BFe10-1-1.BFe30-1-1
5.3The size deviation of the heat exchange tube shall comply with the provisions of Table 6. Heat exchange tube
Low fin tube ND
Type A commercial efficiency tube NJA
Type B win efficiency tube NJB
Fing distance force
5.4The allowable deviation of the fixed length of the heat exchange tube is -mm. 5.5
The curvature of the heat exchange tube is not allowed to exceed 2mm/m. Heat exchange tube status
Ya, M
Wing tip height:
Inner west height
±0, 05
Standard code
GB 1527.G13 8890
Wing outer diameter
5.6 Both ends of the heat exchange tube should be cut flat and burrs should be removed. The inclination of the cut end is allowed to be no more than 21. Warp thickness
5.7 Both ends of the enhanced heat exchange tube should retain a smooth section without processing. The length of the smooth section should be determined according to the requirements of the buyer. 5.8 The heat exchange tube should not have fin cracks, tube wall cracks, and should not have defects such as fin crushing and damage. 5.9 Whether the surface of the heat exchange tube is cleaned and passivated is generally negotiated by the supply and demand parties! 5.10 The heat exchange tubes shall be guaranteed to withstand a gauge pressure of 2.0MPa without leakage. 5.11
Each high-efficiency tube must be subjected to a water pressure test, with a test pressure of 2.0MPa for 15s without leakage. 49
6 Inspection rules
JB/T 7226- 94
6.1 For each batch of heat exchange tubes produced, the manufacturer's quality inspection department shall randomly select five tubes and inspect them according to the requirements of Articles 5.3 to 5.11 of this standard. If one tube fails to meet the standards, 10 tubes shall be randomly inspected. If there are still tubes that fail to meet the standards, the entire batch shall be scrapped or inspected one by one. 6.2 Each batch of heat exchange tubes shall consist of heat exchange tubes of the same brand, state and specification. 6.3 The purchaser shall accept the heat exchange tubes according to this standard. If the quality is found to be inconsistent with this standard, it shall be reported to the supplier within two months from the date of receipt. If the supplier confirms that there is a quality problem, it shall be replaced or returned. 7 Quality certificate
For heat exchange tubes that have passed the inspection, the manufacturer shall fill in the product quality certificate and provide it to the user. The certificate shall at least include the following contents:
Name and model of heat exchange tube;
Report on brand, status and material of heat exchange tube; manufacturing date;
Name of manufacturer.
8 Packaging and marking
8.1 The packaging method shall be determined by the manufacturer, but the following requirements shall be met after packing: rainproof and vibration-proof;
b. Do not damage the surface of the heat exchange tube and do not deform the heat exchange tube
When the packaging box is inverted or placed on its side, the heat exchange tube is inactive in the box. 8.2 The following markings should be made on the packaging box:
Name and address of the shipping unit;
Name and address of the receiving unit;
Rainproof and moisture-proof markings;
Model, number and net weight of heat exchange tubes;
Total weight of the packaging box.
Additional instructions:
This standard was proposed and coordinated by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by the Hefei General Machinery Research Institute of the Ministry of Machinery Industry, Shanghai Copper Tube Factory, Shijiazhuang Agricultural Modernization Research Institute, and Shijiazhuang High-efficiency Heat Exchanger Component General.
The main drafters of this standard are: Li Yunfu, Chen Qirong, Cui Jianwei, and Lv Naixin. 450
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