GB/T 22755-2026Brass fittings with press compression sleeves for piping systems (English PDF)

6.3 Dimensions

6.3.1 The schematic diagram of the pipe fitting body nozzle structure is shown in Figure

2.The basic dimensions should conform to the contents of Table 4.

6.5.2 Hydrostatic Performance According to the test conditions specified in Table 7, a hydrostatic test shall be conducted in accordance with 7.5.1.There shall be no leakage at any connection point during the test.

6.5.4 Cyclic Pressure Shock Performance According to the test conditions specified in Table 9, a cyclic pressure impact test shall be conducted in accordance with 7.5.3.There shall be no leakage at any connection point during the test.

6.5.5 Pull-out resistance According to the test conditions specified in Table 10, the pull-out test shall be conducted in accordance with 7.5.4.No relative axial pull-out shall occur at the connection between the fitting and the pipe. move.

6.5.6 Bending performance According to the test conditions specified in Table 11, a bending test shall be conducted in accordance with 7.5.5.During the test, there shall be no leakage at any connection point.

6.5.7 Vacuum performance According to the test conditions specified in Table 12, the vacuum performance test shall be carried out in accordance with 7.5.6, and the change in vacuum pressure shall not exceed

0.005 MPa.

6.6 Torsional resistance For pipe fittings with threaded connections, the test shall be conducted according to 7.6.The torque specified in Table 13 shall be applied to the threaded connection end; there should be no breakage or deformation. It complies with the provisions of 6.4.

6.7 Resistance to stress corrosion This clause applies to high-risk scenarios such as shipbuilding and chemical industries, and copper alloy pipe fittings should have resistance to stress corrosion. Copper alloys that meet the following conditions are considered to have resistance to stress corrosion and do not need to undergo stress corrosion resistance testing.

---Copper alloy pipe fittings with a zinc content of less than 10%;

---Copper alloy pipe fittings made of copper-tin-zinc alloys (such as CuSnZnPb) and copper-zinc-silicon alloys with a silicon content of not less than 2%;

---The Brinell hardness measured according to GB/T 231.1 shall not exceed 110HBW2.5/62.5, or the Vickers hardness measured according to GB/T 4340.1 shall not exceed 110HBW2.5/62.5. Copper alloy pipe fittings with a strength not exceeding 134HV5.

6.8 Hygiene performance According to section 7.8, the hygienic properties of materials in direct contact with drinking water in pipe fittings shall meet the requirements of GB/T 17219.

7.3 Dimensions Use a measuring tool with a graduation of

0.01 mm for inspection.

7.4 Air tightness performance Install the pipe fitting body on a dedicated pressure testing machine, immerse the pipe fitting body in a water tank at room temperature, and slowly inject [something] into the pipe fitting body. Use clean compressed air at 0.8MPa±0.05MPa, maintain the pressure for more than 15 seconds, and observe whether any bubbles appear.

7.5 System Applicability

7.5.1 Hydrostatic performance The test medium inside and outside the test assembly is water, and the test is conducted in accordance with the provisions of GB/T 6111.

7.5.2 Thermal cycling performance Proceed in accordance with GB/T 19993.

7.5.3 Cyclic Pressure Shock Performance The test shall be conducted according to the cyclic pressure impact performance test method specified in GB/T 18992.2.

7.5.4 Pull-out resistance The test shall be conducted in accordance with the provisions of GB/T 15820.

7.5.5 Bending performance The bending performance test shall be conducted according to the method specified in GB/T 18992.2.

7.5.6 Vacuum performance The test shall be conducted according to the vacuum performance test method specified in GB/T 18992.2.

7.6 Torsional resistance

7.6.1 Test Instruments The torque wrench used for the torsional performance test has a range of

1.5 to 3 times the test torque and an accuracy of ±1%.

7.6.2 Test Procedure The experimental steps are as follows:

a) Fix the pipe fitting to be tested in the position shown in Figure 5;

b) Screw the torque wrench through the thread of the adapter into the threaded end of the pipe fitting being tested; the thread length of the pipe fitting being tested should be at least longer than the corresponding thread length. The adapter's thread length is 2mm;

c) Apply torque smoothly and gradually using a torque wrench, and hold for 10 seconds after reaching the torque value specified in Table 13;

d) After removing the torque, conduct an airtightness test as specified in 7.4, and determine whether the result meets the requirements of 6.6.

7.7 Resistance to stress corrosion The test shall be conducted according to the ammonium chloride test method specified in GB/T 10567.2.

7.8 Hygiene Performance Proceed according to GB/T 17219.

8.2 Factory Inspection

8.2.1 Inspection Items Products must pass the manufacturer's inspection before leaving the factory. The inspection items are

8.2.2 Batching and Sampling Principles Pipe fittings produced continuously using the same raw materials, process, and specifications constitute one batch, with each batch not exceeding 20,000 pieces, and continuous production lasting 7 days. When production volume is less than 20,000 units, each batch is considered as 7 days' worth of production, and samples required for factory inspection are drawn from the batch. This is done according to GB/T 2828.1. Sampling will be conducted using a special inspection level of S-3 and a single sampling plan for normal inspection.

8.2.3 Judgment Rules The Acceptable Quality Limit (AQL) for inspection items

6.3 is 4.0, and the Acceptable Quality Limit (AQL) for inspection item

8.3 Type Testing

8.3.1 Inspection conditions Type testing shall be conducted under any of the following circumstances.

a) Initial production or production transferred to another factory;

b) If significant changes occur in the process after formal production, potentially affecting product performance;

c) Resumption of production after a one-year hiatus;

d) When the factory inspection results differ significantly from the previous type inspection results.

8.3.2 Inspection Items Type testing items are specified in Table

14.The following requirements apply only under the corresponding conditions for type testing. a)

6.5.6 applies when the diameter of the metal ferrule connection end of the pipe fitting is greater than or equal to phi32mm. b)

6.7 Applicable when pipe fittings are used in high-risk scenarios such as shipbuilding and chemical industries. c)

6.8 Applicable when the pipe fittings are in direct contact with drinking water.

8.3.3 Sampling Method Samples required for type testing shall be randomly selected from the batches that have passed factory inspection, and the sampling quantity shall meet the requirements of each test method in Chapter 7. Require.

8.3.4 Judgment Rules If all test items of all samples meet the requirements of this document, the type test is deemed (qualified); if the hygiene performance does not meet the requirements of this document, the type test is deemed (qualified). According to the document, if the type test is deemed unqualified, the test should be directly deemed unqualified; if other test items besides hygiene performance fail the initial test, the test should be conducted again from the same test. Double the sampling in a batch of products, and retest only the non-conforming item. If the retest result still does not comply with the provisions of this document, the type inspection shall be deemed invalid. The test failed.

9.2 Packaging

9.2.1 The following information should be indicated on the product packaging.

a) Product name, model, specifications, and applicable standard number;

b) Manufacturer's name and address;

c) Manufacturing date;

e) Weight (gross weight, net weight);

f) External dimensions (length × width × height).

9.2.2 Each product shall be accompanied by a certificate of conformity and an installation and operation manual. The certificate of conformity shall include the inspector's code and the inspection date. (For drinking water use) Products should be specifically labeled accordingly.

Note. Each product refers to the smallest packaging unit at the factory. For example, small-sized pipe fittings may be shipped in boxes or packages as the smallest unit, in which case only a certificate of conformity is needed. Includes installation and user manual.

9.2.3 Product packaging should be sturdy and undamaged, and the weight of each unit should comply with relevant transportation regulations.

9.3 Transportation During transportation, the product should be protected from sun and rain, handled with care, protected from heavy pressure, and impacts should be avoided. It should not be transported together with corrosive substances.

9.4 Storage The product should be stored in a well-ventilated and dry indoor environment, and should not be stored with corrosive substances. It should also be kept at least.200mm off the ground.