Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T8512—1996
For water transport
Published on December 13, 1996
Plastic-coated hose
Implemented on July 1, 1997
Ministry of Machinery Industry of the People's Republic of China
JB/T8512—1996
This standard is a revision of GB947688 "Plastic-coated hose" in view of the development of plastic-coated hose products in my country. The applicable contents of GB947688 are retained during the revision, and the following modifications are made: 1. Low 1. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses: 2. The standard specifies the following types of plastic-coated hoses: 3. The standard specifies the following types of plastic-coated hoses: 4. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses: 2. The standard specifies the following types of plastic-coated hoses: 3. The standard specifies the following types of plastic-coated hoses: 4. The standard specifies the following types of plastic-coated hoses: 5. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses: 2. The standard specifies the following types of plastic-coated hoses: 3. The standard specifies the following types of plastic-coated hoses: 4. The standard specifies the following types of plastic-coated hoses: 5. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses: 2. The standard specifies the following types of plastic-coated hoses: 3. The standard specifies the following types of plastic-coated hoses: 4. The standard specifies the following types of plastic-coated hoses: 5. The standard specifies the following types of plastic-coated hoses: 6 ...6. The standard specifies the following types of plastic-coated hoses: 1. The standard specifies the following types of plastic-coated hoses:
The main drafters of this standard are: Xu Youyi, Lin Kan, Li Azhang, Zhu Delan, Zhao Xiang. 1
1 Scope
Machinery Industry Standard of the People's Republic of China
Plastic-coated hose
For water delivery
JB/T8512-1996
This standard specifies the specifications, models, technical requirements, test methods, inspection rules and markings, packaging, transportation and storage of plastic-coated hoses. This standard is applicable to plastic-coated hoses for water delivery in mobile and semi-fixed sprinkler machinery and other irrigation systems, industrial and mining construction industries. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards will be revised. All parties using this standard should explore the possibility of using the latest version of the following standards: GB282887 Batch inspection counting sampling procedure and sampling table (applicable to continuous batch inspection) 3 Specifications and models
3.1 Specifications
3.1.1 Plastic-coated hoses are divided into 25, 40, 50, 65, 75, 80, 90, 100, 125, 150, 200, 250, 300mm according to the nominal inner diameter. 3.1.2 According to the working pressure, they are divided into 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8MPa 3.1.3 Plastic-coated hoses of other sizes and pressure specifications can be agreed upon by both parties. 3.2 Model
3.2.1 Model indication method
The model of the plastic-coated hose consists of uppercase Latin letters and Arabic numerals, and its meaning is as follows: TS
10 times the working pressure value (MPa). If the obtained value is less than 10, add 0 in the first digit. Plastic-coated hose
Nominal inner diameter, mm
3.2.2 Marking example
The plastic-coated hose with a nominal inner diameter of 65mm and a working pressure of 0.8MPa is marked as: 65TS08
The plastic-coated hose with a nominal inner diameter of 50mm and a working pressure of 1.0MPa is marked as: 50TS10
4 Technical requirements
4.1 The nominal inner diameter, its limit deviation and working pressure of the plastic-coated hose shall comply with the requirements of Table 1. 4.2 The fixed length of the plastic-coated hose is 15m, 20m, 25m, 30m or 60m, and no lower deviation is allowed. 4.3 The pressure test pressure of the plastic-coated hose should not be less than 3 times its working pressure. For the plastic-coated hose with a working pressure of 0.8MPa, the pressure-resistant test pressure of the Ministry of Machinery Industry approved on December 13, 1996
1997-07-01
should not be less than 2.5MPa.
Nominal inner diameter
Limit deviation mm
JB/T8512-1996
Working pressure
4.4 The surface of the plastic-coated hose should be smooth and flat. There should be no defects such as scratches, broken wires, warp withdrawal, loose warp, warp paralleling, inner and outer grooves, degumming, pores and coating inclusions.
5 The uniformity of the wall thickness of the plastic-coated hose is evaluated by its thickness ratio, and the thickness ratio shall not exceed 1.3. 4.5
5 Test method
1 Main test instruments and equipment
5.1.1 Pressure gauge: The accuracy is ±2%, and the range is 0-4MPa. 5.1.2
Gauge: The reading scale is not greater than 0.02mm, and the range is 0~5mm. Test pump: The water pressure should be able to reach 4MPa.
5.1.4 Pressure stabilizing device: When the water pressure is not greater than 3.0MPa, after pressure stabilization, the pressure gauge indication fluctuation should be within the range of ±0.05MPa; when the water pressure is greater than 3.0MPa, the pressure gauge indication fluctuation should be within the range of ±0.10MPa. 5.1.5 The technical requirements of other measuring instruments should be consistent with the test methods. 5.2 Test conditions
5.2.1 The standard test conditions for dimensional measurements are an ambient temperature of 23°C ± 3°C. The standard test conditions for pressure resistance tests are as follows: 5.2.2
The test medium is neutral water;
The ambient temperature is 23°C ± 3°C, the medium temperature should be as close to the ambient temperature as possible, and the maximum temperature difference should not exceed 6°C. 5.3 Test method
5.3.1 Measurement of nominal inner diameter
According to the size of the nominal inner diameter of the plastic-coated hose, use the inner diameter full-shape gauge measurement method or the unfolded measurement method2
JB/T8512-1996
For plastic-coated hoses with a nominal inner diameter less than or equal to 150mm, cut a sample with a length of not less than 0.5m and the two ends cut flush, or use the sample of 5.3.3 and use the inner diameter full-shape gauge (its main dimensions and limit deviations are shown in Figure 1 and Table 2) to measure the inner diameter of the two ends of the sample. The plastic-coated hose is qualified if it can match or cannot match the go gauge and the stop gauge, otherwise it is unqualified. For plastic-coated hoses with a nominal inner diameter greater than 150mm, cut a sample with a length of 20~30mm and the two ends cut flush. Cut the sample longitudinally, use a steel ruler to measure the actual size of the inner wall of the plastic-coated hose along the cross-sectional direction, and calculate the equivalent diameter of the plastic-coated hose with a pi of 3.14, retaining one decimal place. 24-35#考
Nominal inner diameter
Determination of wall thickness uniformity
Take a sample with a length of 30~50mm from the end of the plastic-coated hose, and cut the two ends flush. Measure the maximum and minimum values of the wall thickness of the plastic-coated hose as shown in Figure 2, and record and calculate the ratio of the maximum and minimum values (i.e., thickness ratio).
5.3.3 Pressure test
Take a sample with a length of 1.2m from the end of the plastic-coated hose and test it according to the following requirements:3
JB/T8512-1996
a) One end of the sample is connected to the water pressure source, and the other end is plugged with a plug after the air is exhausted, and the effective length of the pressure test part of the sample is not less than 1m:
b) Turn on the water pressure source and slowly pressurize at a constant rate until the plastic-coated hose bursts or the pressure reaches the specified value of 4.3. If the pressure at the time of bursting is less than the specified value of 4.3, record the pressure at the time of bursting. Otherwise, record it as greater than the specified value:c) When the ambient temperature does not meet the standard test conditions and the difference between the ambient temperature and the medium temperature does not exceed 6℃, the pressure test index can be converted according to Appendix A (Appendix of Prompt). 6 Inspection rules
6.1 Plastic-coated hoses should be inspected and tested to be qualified and accompanied by product certificates before they can leave the factory. 6.2 During the inspection, the hoses of the same variety, specification and raw materials of the same batch shall be considered as one batch. 6.3 Inspection test items include:
a) Nominal inner diameter and its deviation:
b) Fixed length:
c) Pressure test;
d) Surface quality:
e) Wall thickness uniformity:
Packaging;
g) Marking.
6.4 Sampling inspection and judgment and disposal rules shall be in accordance with the provisions of GB2828. A normal inspection and one-time sampling plan can be adopted, S-1 special inspection level, and the qualified quality level (AQL) is 6.5: It can also be determined by negotiation between the supply and demand parties. 7 Marking, packaging, transportation and storage bZxz.net
7.1 Each plastic-coated hose of a certain length should be marked with the factory name, trademark, model, specification, fixed length, etc. 7.2 The plastic-coated hose needs to be rolled into a disc shape and firmly packed with packaging cloth or moisture-proof material. 7.3 Each package should contain plastic-coated hoses of the same specifications and models. 7.4 Each package must contain a factory inspection certificate and a user manual. The certificate should at least include: factory name, trademark, product name, model specification, fixed length, production date or batch number, inspector and number of the standard implemented. 7.5 Each package must be marked with: factory name, trademark, product name, model specification, cumulative fixed length, production date, gross weight and necessary warning signs for heat protection and sharps protection
7.6 During transportation, plastic-coated hoses should be protected from severe impact and exposure to the sun, and should avoid contact with corrosive media and sharps. 7.7 Plastic-coated hoses should be stored in a cool and ventilated warehouse, and the ambient temperature in the warehouse should not exceed 40°C. 4
JB/T8512-1996
Appendix A
(Suggested Appendix)
Conversion formula for pressure index of plastic-coated hose pressure test The pressure test pressure index value is converted according to formula (A1): P.= p.-C(t -23) ......
Wherein: p', - the pressure test pressure index value that the plastic-coated hose should reach when it bursts under actual test conditions, MPa; ..(A1)
Under standard test conditions (ambient temperature 23℃±3℃, the maximum temperature difference between the medium temperature and the ambient temperature should not exceed 6Pn
℃), the pressure test pressure index value that the plastic-coated hose should reach when it bursts (that is, the specified value in 4.3), MPaC-temperature correction coefficient (see Table AI), MPa/℃:-the arithmetic mean of the medium temperature and the ambient temperature during the test, ℃. Note: pn is accurate to 0.01MPaa
A2 If the measured pressure resistance test value when the plastic-coated hose bursts is greater than p., then record the pressure resistance test pressure greater than the specified value in 4.3, otherwise convert it into the test pressure value when the plastic-coated hose bursts under standard test conditions according to formula (A2), and record it as such. p=p+C(t-23).
Where: p
The pressure resistance test pressure index value that the plastic-coated hose should reach when it bursts under actual test conditions, MPa is equivalent to the test pressure index value that the plastic-coated hose should reach when it bursts under standard test conditions, MPa: Temperature correction coefficient (see Table AI), MPa/℃; The arithmetic mean of the medium temperature and the ambient temperature during the test, ℃. Note: p is accurate to 0.01MPa.
Nominal inner diameter mm
Temperature correction coefficient 10
(A2)
(5℃≤35℃ long)
≥200
Mechanical industry standard
Plastic-coated hose for water transport
JB/T8512-1996
Published by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2, Shouti South Road, Beijing: Postal Code 100044 ）*
Book size 880×1230
1/16 Printing sheet 1/2
Word count 12000
First edition in February 1997
First printing in February 1997
Print run 00,001-500
Price 5.00 yuan
No. 97-051
Mechanical Industry Standard Service Network: http/AvwwJB.ac.cn9668 /
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