This standard uses marine shellfish (bivalves) as environmental monitoring organisms and specifies the quality requirements for marine organisms of various marine use functions. This standard applies to the sea areas under the jurisdiction of the People's Republic of China. This standard applies to natural and artificially cultured marine shellfish. GB 18421-2001 Marine Biomass Quality GB18421-2001 Standard Download Decompression Password: www.bzxz.net

GB/T 18422 2001
This standard is equivalent to the international standard IS(4080:1991 Rubber and plastic hoses and their assemblies-Determination of air permeability".
The main differences between this standard and the international standard IS01080:1991 are as follows: "· In order to make the test device diagram more concise and easy to understand, Figure 1 adds A end and notes; in order to facilitate understanding, the header of Table 1 is adjusted. This standard is proposed by the State Administration of Petroleum and Chemical Industry. This standard is issued by the National Technical Committee for Standardization of Rubber and Rubber Products and is under the jurisdiction of the Hose Sub-Technical Committee. The responsible drafting unit of this standard: Shenyang Rubber Research and Design Institute of China Rubber Group. The main drafter of this standard: Jin Xuehua
GB/T18422-2001
ISO Foreword
The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies (ISO member bodies). The work of formulating international standards is usually carried out by the ISU technical committees. All Any member body interested in establishing a technical committee has the right to participate in the committee. International organizations, governmental and non-governmental, in liaison with ISO may also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all aspects of electrotechnical standardization. Draft international standards adopted by the technical committees are circulated to member bodies for voting. When published as international standards, they require at least 75 votes from the member bodies voting in favor. International Standard 1SO4080 was developed by 1SO/TC45 Rubber and Rubber Products Technical Committee and SC1 Hoses (Rubber and Plastics) Subcommittee.
This third edition abolishes and replaces the first edition (IS0) 4080:1987). It is a technical revision of the first edition with the addition of a test method (Method 3). 202
National Standard of the People's Republic of China
Rubber and Plastic Hoses and Assemblies
Determination of Air Permeability
Kubber and plastics hoses and hose assemblies-Determination of permeability to gasGB/T18422—2001
cqvI04080.1991
Warning: Personnel using this standard should be familiar with the test procedures. This standard is intended to cover all safety issues that may arise from the use of this standard. It is the user's responsibility to establish appropriate safety and health systems to ensure compliance with national regulations. 1 Scope
This standard specifies three methods for determining the volume of gas that penetrates through the entire rubber or plastic hose within a specified time. Method 1: The permeability of the entire hose wall to the test gas is determined by using the test gas. This method is used when evaluating the permeability characteristics of hoses with perforated outer rubber layers.
Method 2: It is used to determine the permeability of the inner rubber layer and reinforcement layer of the hose to the test gas. When determining the permeability characteristics of hoses with unperforated outer rubber layers, gas usually seeps out from the fabric reinforcement layer at the cut end of the hose. This method is used at this time. Method 3: The permeability of the hose wall to the test gas is accurately determined within a specified time. These methods are applicable to test gases that are insoluble in water. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest version of the following standards. GR/T2041--1991 Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens (eqvISO471:1983) 3 Test apparatus
3.1 The water tank can be maintained at the specified temperature and has sufficient length to accommodate the specimen. 3.2 The gas supply source is equipped with a suitable pressure gauge and an emergency over-current cut-off valve for use in the event of hose failure. 3.3 The gas collection device consists of a measuring cylinder, and sometimes contains a device suitable for each of the three methods, as shown in Figures 1 to 3. The capacity and accuracy of the measuring cylinder should be selected according to the expected volume of gas collected. 3.4 The barometer is used to record the air pressure during the test. 3.5 Two thermometers are used to record the water temperature and air temperature at the gas receiving point. The schematic diagrams of the test devices for these three test methods are shown in Figures 1 to 3. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on August 28, 2001 and implemented on May 1, 2002
Gas supply
GB/T18422-2001
Gas collecting cotton
1m (free length of hose)
Note: The A end of the sample should be far away from the right side of the cylinder so that bubbles cannot escape from it and rise into the measuring cylinder. Figure! Test device used in method 1. Schematic diagram of the test device used in method 2
Instructions for use:
1JS0)4080:1991 In Figure 1, \A end\—word. 2IS04080:t091 No note in Figure 1.
Gas collecting tank
4 Test specimen
Hose joint
Thin pipe
GB/T184222001
Jinhuangpu
Hose joint
Fast gas sourcebzxZ.net
Figure 3 Schematic diagram of test device for method 3
4.1 For method 1
The test specimen shall be a hose of appropriate length, which is long enough to ensure that the length of the hose exposed under the gas collecting tank is 1m.
4.2 For method 2, the test specimen shall be a hose with a length of 1m. 4.3 For method 3, the length of the hose between the two pipe joints is 0.5m. 5 Adjustment of the test specimen
No test shall be performed within 24 hours of the production of the hose. Before the test, the sample shall be conditioned for at least 3 h at the selected temperature and condensation according to GB/T 2941.
6 Test temperature
The test shall be carried out at the temperature specified in GB/T 2941. 7 Test pressure
Unless otherwise specified, the test shall be carried out at a gas pressure of 1 MPa. 8 Procedure
8-7 Method 1
Close one end of the sample and connect the other end to the specified gas supply (3.2). Before the final closure of the test assembly, purge the test assembly with ~ for 30 s to eliminate trapped air.
Adjust the temperature of the water tank (3.1) to the specified value. Immerse the test assembly in the water tank, apply gas pressure and maintain the pressure for 72 h before collecting the gas. As shown in Figure 1, place the gas collector (3.3) on one side of the sample and record the time required to collect 3.0 cm of gas. Repeat this measurement twice. Another method is to measure the volume of gas collected within 24 hours. If it is necessary to measure the permeability under different pressures, first test at the lowest pressure and then test at a higher pressure. 285
8.2 Method 2
GB/T 18422--2001
Install appropriate inlet and tail joints on the sample, connect the inlet end to the specified gas supply (3.2), and then plug the tail pipe joint. Purge the test assembly with gas, exhaust the air, and finally close the test assembly. Adjust the temperature of the water tank (3.1) to the specified temperature. Apply the test pressure to the hose assembly and maintain it for 24 hours. Then immerse the test assembly and its end connectors in a water tank (3.1) (see Figure 2). Use two graduated cylinders (3.3) at both ends to collect and measure the escaping gas for 1 hour. Maintain the air pressure of the test assembly and remove it from the water tank. Immerse the test assembly in the water tank again and measure the volume of the escaping gas for 1 hour every 24 hours. Then obtain six more measurement values. It is important to note that 1 h After the measurement, remove the assembly instead of leaving it in the water for further immersion, because the exposed textile reinforcement layer will swell and make the test results unrepresentative.
8.3 Method 3
Partially seal one end of the specimen. Connect the other end to the specified gas supply (3.2). Purge the test assembly with gas for 30 seconds before finally closing it. Expel trapped air. Adjust the temperature of the water tank (3.1) to the specified temperature. Insert the test assembly into the broken glass tube and immerse it in the water tank so that they should be inclined at about 20° to the horizontal plane (see Figure 3). Apply gas pressure and maintain for 14 days. Then collect gas for 6 hours, or collect 450 cm2~500 cm2 of gas. Every 24 hRepeat this test procedure until the volume of gas collected in two consecutive times differs within 5%. Calculate the permeability using the average of the two consecutive readings. If you want to determine the permeability under different pressures, first test at the lowest pressure and then at a higher pressure. 9Expression of test results
Calculate the average time to collect 1 cm of gas from the three most measured results. Calculate the gas permeability rate from this value and express it in cubic centimeters of gas per meter of hose per hour [cm*/(m*h). If another method is used, collect the volume for 24 hours (see Section 8.1, paragraph 4),Similar calculations can be made.
9.2 Method 2
Since the test assembly may still contain some air, do not take the first reading. Average the remaining six readings and express the permeability rate in cubic centimeters per meter of hose per hour [cm/m·h]. 9.3 Method 3
The area under investigation is the inner surface of the hose in contact with the gas. The permeability rate of the inner surface of the hose in contact with the gas is expressed in cubic cubic meters of gas per second Lcrn/(tm2·s). Correct all test results for standard temperature 273.15K and standard pressure 101.325kPa under dry conditions. Measure the inner diameter at both ends of the hose and take the average value. The air permeability is calculated using formula (1) and is expressed in cubic centimeters of gas per second per square meter:
858.09 × V(p-pu)
alt(273.15)
Wu Zhong: V
the volume of the collected gas, cm, accurate to ±2.0 cm; the maximum vapor pressure of the collection body, kPa, accurate to ±0.7 kPa; the saturated vapor pressure of water at temperature α (see Table 1), kPa, accurate to ±0.01 kPa; p
the inner diameter of the hose, mm, accurate to ±0.5 mm; the time of collecting gas, 5, accurate to ±305; the temperature of the collection device when collecting gas, ℃, accurate to ±0.10; the length of the hose, m, accurate to ±0.001 m. L-—
GB/T 18422—2001
Table 1 Saturated vapor pressure of liquid water at temperatures of 15℃～35℃ () 0. 1
Test report
3, 606
The test report should include the following contents:
a) Number of this standard;
b) Full name of the test hose:
c) Test gas used;
nl) Test pressure adopted;
e) Test method adopted;
f) Environmental overflow:
|) Test temperature:
c+ 908
h) Air permeability, Method 1 and Method 2 are expressed in cubic centimeters per hour per meter of hose [cm/(m·h), Method 3 is expressed in cubic centimeters per second per square meter [cm\/(m·s); 1) Any special observations;
i) Test period.
Usage description:
The meter is factory adjusted for ease of understanding.
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