QC/T 597.3-2019 English PDF (QCT597.3-2019)

This Part specifies the requirements, test methods, inspection rules, storage of nonreusable sealing coating, which is pre-applied onto the external thread fasteners, for the purpose of preventing leakage AND having the sealing function.

QC/T 597.3-2019
QC
AUTOMOBILE INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 43.040
T 31
Replacing QC/T 597-1999
Specification for fastener with adhesive coating - Part 3:
Sealing coatings
ISSUED ON: AUGUST 02, 2019
IMPLEMENTED ON: JANUARY 01, 2020
Issued by: Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Requirements ... 4
4 Test method ... 6
5 Inspection rules ... 8
6 Storage ... 8
Specification for fastener with adhesive coating - Part 3:
Sealing coatings
1 Scope
1.1 This Part specifies the requirements, test methods, inspection rules, storage of non- reusable sealing coating (hereinafter referred to as "sealant"), which is pre-applied onto the external thread fasteners (bolt, screw and stud, hereinafter referred to as "bolt"), for the purpose of preventing leakage AND having the sealing function.
1.2 This Part is applicable to the sealing of threaded connection pair, in accordance with GB/T 196, GB/T 197 or GB/T 12716.
2 Normative references
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) is applicable to this standard.
GB/T 196 General purpose metric screw threads - Basic dimensions
GB/T 197 General purpose metric screw threads - Tolerances
GB 11121 Gasoline engine oil
GB/T 12716 Pipe threads with the thread angle of 60 degrees where pressure-tight joints are made on threads
GB 17930 Gasoline for motor vehicles
GB 19147 Automobile diesel fuels
GB 29743 Motor vehicle engine coolant
3 Requirements
3.1 Sealing at room temperature
3.1.1 After the bolts coated with sealant are fully screwed into the screw holes AND then come into contact with the coolant, it shall ensure that the thread pair does not leak. The test method shall be in accordance with the provisions in 4.2.1.
3.1.2 The bolts coated with sealant are fully screwed into the screw holes; the thread pair shall not leak, after the compressed air is introduced. The test method shall be according to the provisions of 4.2.2.
3.1.3 The bolts coated with sealant are fully screwed into the screw holes; the threaded pairs shall not leak, after being filled with water. The test method shall be in accordance with the provisions in 4.2.3.
3.2 Aging resistance
3.2.1 The bolts coated with sealant are fully screwed into the screw holes AND then come into contact with the engine oil; it shall ensure that the thread pair does not leak. The test method shall be in accordance with the provisions in 4.3.1.
3.2.2 After the bolts coated with sealant are fully screwed into the screw holes AND then come into contact with fuel (gasoline or diesel), it shall be ensured that the thread pair does not leak. The test method shall be in accordance with the provisions in 4.3.2. 3.2.3 The bolts coated with sealant are fully screwed into the screw holes AND then contact with the gearbox oil, it shall ensure that the thread pair does not leak. The test method shall be in accordance with the provisions in 4.3.3.
3.3 Heat resistance
After the bolts coated with sealant are fully screwed into the screw holes, place them at 150 °C for 5 hours; then place them at room temperature, which shall meet the requirements of 3.1 and 3.2, respectively.
3.4 Cold resistance
After the bolts coated with sealant are fully screwed into the screw holes, place them at -30 °C for 5 hours; then place them at room temperature, which shall meet the requirements of 3.1 and 3.2, respectively.
3.5 Resistance to cold and heat shock
After the bolts coated with sealant are fully screwed together with the screw holes, they shall be resistant to cold and heat shocks. The test method shall be according to the provisions of 4.4.
3.6 Bolt pre-painted parts and length
Apply the sealant to the bolt threads, for a length equal to the thread diameter ± 1 pitch. Unless otherwise specified, avoid coating within 2 full threads of the bolt end. In order to fully ensure the sealing performance, the sealant coating length shall not be less than 3 full pitches. The sealant is applied at an angle of 360° (sealant is applied all around). 4.1.2.3 The bolts shall not produce clamping force, after they are screwed together. 4.1.2.4 When the bolts are screwed into the screw holes on the pressure vessel, the sealant shall be fully engaged with the screw holes.
4.2 Leakage test under room temperature, different test media and working conditions
4.2.1 Coolant
Use the liquid, which is fully mixed by 40% water, fluorescent agent, cooling liquid in accordance with GB 29743, as the test medium. Screw the bolts, which are coated with sealant, into the screw holes of the 1 MPa steel pressure vessel. Keep the pressure for 1 min. Observe under ultraviolet light. The thread pair shall have no leaks. 4.2.2 Compressed air
Use compressed air as the test medium. Apply soap solution to the screwed part of the bolt. Keep the pressure in the screw hole of the 1 MPa steel container, for 1 min. The thread pair shall not have any leakage.
4.2.3 Water
For bolts coated with sealant, use water as the test medium. Keep the pressure in a steel pressure vessel of 1 MPa, for 1 min. There shall be no leakage in the thread pair. 4.3 Aging resistance test under different test media and working conditions 4.3.1 Engine oil
Use the liquid, which is fully mixed by the engine oil that complies with the provisions of GB 11121 AND fluorescent agent, as the test medium. Screw the sealant-coated bolts into the screw holes of the steel pressure vessel, which has a pressure of 0.4 MPa. Hold the pressure, under the environmental conditions of (150 ± 2) °C, for 5 h. Observe it under ultraviolet light. The thread pair shall not show any leakage.
4.3.2 Fuel (gasoline or diesel)
Use the liquid, which is fully mixed with the gasoline for vehicles specified in GB 17930 or diesel oil for vehicles specified in GB 19147, fluorescent agent, as the test medium. Screw the bolts coated with sealant into the screw holes of the 0.4 MPa steel pressure vessel. Hold the pressure at (70 ± 2) °C for 5 hours. When viewed under ultraviolet light, there shall be no leakage from the threaded pair.
4.3.3 Transmission oil