This standard specifies the test principles, test conditions, test equipment, test procedures, judgment conditions and test reports of fire resistance tests of ventilation ducts under standard fire conditions. This standard applies to pipes of various materials installed in air conditioning and ventilation systems. This standard applies to ventilation ducts with branches, interfaces or without branches and interfaces. This standard applies to ventilation ducts where the flame comes from inside the duct. This standard does not apply to ventilation ducts where the flame comes from outside the duct. The fire resistance test of smoke exhaust ducts can be carried out in accordance with this standard. GB 17428-1998 Fire resistance test method for ventilation ducts GB17428-1998 standard download decompression password: www.bzxz.net

GB17428-1998
This standard is formulated in view of the installation, use and materials of ventilation ducts in various types of buildings in China, so as to put forward a comprehensive judgment condition for the fire resistance performance of ventilation ducts. The International Organization for Standardization ISO officially promulgated the international standard ISO6944 "Fire Resistance Test for Ventilation Ducts" in 1985, but its content is far from the actual installation and use in my country. In order to make this standard more in line with my country's national conditions, ISO6944 was not specifically adopted in the formulation of this standard, and its content was only referenced. This standard was proposed by the Ministry of Public Security of the People's Republic of China. This standard is under the jurisdiction of the National Fire Protection Standardization Technical Committee. The drafting unit of this standard: Tianjin Fire Science Research Institute of the Ministry of Public Security. The main drafters of this standard: Ji Xiangan, Jie Fenglan, Chen Yingchun. This standard was first issued in July 1998.
This standard is entrusted to the Tianjin Fire Science Research Institute of the Ministry of Public Security for interpretation. 318
1 Scope
National Standard of the People's Republic of China
Fire resistance test method of ventilation ducts
Fire resistance test method of ventilation ductsGB 17428-1998
This standard specifies the test principle, test conditions, test equipment, test procedures, judgment conditions and test reports of fire resistance test of ventilation ducts under standard fire conditions.
This standard is applicable to ducts of various materials installed in air-conditioning and ventilation systems. This standard is applicable to ventilation ducts with branches, interfaces or without branches, interfaces. This standard is applicable to ventilation ducts where the flame comes from inside the duct. This standard is not applicable to ventilation ducts where the flame comes from outside the duct. The fire resistance test of smoke exhaust ducts can be carried out with reference to this standard. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by 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 versions of the following standards. GB9978-88 Fire resistance test method for building components GB15930--1995 Test method for fire dampers
3 Test principle
Measure the time for a test piece of a certain size to meet the fire resistance stability and fire resistance integrity under the specified test conditions. 4 Test conditions
4.1 Heating conditions
The heating conditions shall meet the requirements of 3.1 in GB9978-88. 4.2 Pressure conditions
The pressure conditions shall meet the requirements of 3.2 in GB9978-88. 4.3 Fire conditions
One end of the test piece is open and exposed to the fire source. The smoke window effect is simulated by the induced draft system device to make the smoke and fire spread inside the test piece. 4.4 Other conditions
The regulating valve connected to the rear end of the test piece should be in the closed state, and the smoke leakage of the regulating valve should be between 970 and 1000Nm2/h·m2 (under standard conditions).
5 Test equipment
5.1 Fire test furnace
The fire test furnace shall meet the requirements of 5.5.1.1 of GB15930-1995. 5.2 Temperature measurement system
Approved by the State Administration of Quality and Technical Supervision on July 15, 1998 and implemented on June 1, 1999
GB 17428-1998
The temperature measurement system shall meet the requirements of 2.3.1 of GB9978--88. 5.3 Draft fan system
The Draft fan system includes the Draft fan, air inlet valve, regulating valve and connecting pipes. 5.4 Gap measuring instrument
The gap measuring instrument is made of stainless steel rods, with two specifications of $6mm and $25mm in diameter, and equipped with an insulated handle. 5.5 Accuracy of measuring instruments
The measuring system shall achieve the following accuracy:
Temperature: furnace temperature ±15℃
Others: ±5℃
Pressure: ±5Pa
Time: ±10 s
Gap measuring instrument: ±0.5mm
6 Requirements for test pieces
6.1 Dimensions
The cross-sectional dimensions of the test piece shall be the same as the cross-sectional dimensions of the pipeline actually used in the project. When the size of the test piece cannot be determined, a test piece with a ratio of the shortest side to the longest side of 1:4 and a long side of 1m or close to 1m shall be tested. The length of the test piece shall not be less than 2m and shall include at least one common interface.
6.2 Installation
The installation of the test piece shall reflect the actual use as much as possible and meet the requirements of Figure 1. Test furnace
6.3 Specimen maintenance
Airflow direction
一Interface: 2一Test piece: 3—Sensor outlet 34—Regulating valve; 5—Connecting pipe 6—Condenser pipe; 7—Draft fan connecting pipe Figure 1 Specimen installation diagram
Specimens containing hygroscopic materials or materials that can be affected by moisture should be dried or maintained to reach or approach normal use conditions. 7 Test procedure
7.1 The specimen is installed in place, the induced draft fan is started, and the air inlet valve and regulating valve are adjusted to keep the flue gas leakage of the regulating valve connected to the test piece between 700 and 1000Nm/hm2.
7.2 The test furnace is ignited. When the average temperature in the furnace reaches 50℃, the test starts. The furnace temperature is controlled so that the average temperature rise reaches the requirements of 3.1 in GB 9978--88. wwW.bzxz.Net
GB 174281998
7.3 After 10 minutes from the start of the test, the furnace pressure shall be controlled within the range of 15Pa±5Pa. 7.4 The test shall be observed, measured and recorded in accordance with the provisions of Chapter 8. 7.5 During the test, if the test piece encounters any of the conditions specified in Chapter 9 that reach the fire resistance limit of the test piece, or if the above conditions do not occur but the fire resistance time of the test piece reaches 1.5, the test can be terminated. 8 Observation, measurement and recording
8.1 Measurement of temperature in the furnace
The furnace temperature measuring device shall meet the requirements of 5.2 and record the measured temperature once no more than 1min. 8.2 Measurement of pressure in the furnace
The furnace pressure measuring device shall meet the requirements of 5.1 and record the measured pressure value once no more than 1min. 8.3 Test piece integrity measurement
8.3.1 Cotton pad test
The cotton pad test shall be carried out in accordance with the provisions of 5.3.6 of GB9978-88. The time when the cotton pad is ignited and the position on the test piece shall be recorded. Note: The cotton pad test may not be carried out on metal pipes. 8.3.2 Crack measurement
The openings and cracks on the surface of the test piece during the test shall be measured once at regular intervals using a crack measuring instrument. The length of the time interval is determined by the speed of damage to the test piece. Two specifications of crack measuring instruments shall be used in turn during the measurement. When the following situations occur, the time and position of the opening or crack shall be recorded. a) A crack measuring instrument with a diameter of 6 mm can penetrate the test piece from the opening or crack and can move a distance of 150 mm along the opening or crack.
b) A crack measuring instrument with a diameter of 25 mm can penetrate the test piece from the opening or crack. 8.3.3 Flame
When flame appears on the outer surface of the specimen and continues to burn for 10s or more, the time and position of flame appearance shall be recorded.
8.4 Collapse
When the specimen cannot be kept in the original installation position, it is considered that the specimen has collapsed, and the time of collapse shall be recorded. 8.5 Other Observations
The deformation and smoke of the specimen shall be recorded during the test. 9 Judgment Conditions
When any of the following conditions occurs during the test, it indicates that the specimen has lost its fire resistance: a) Flame appears on the specimen and continues to burn for 10s or more. b) When the ladder pad test is carried out according to the provisions of 8.3.1, the cotton pad is ignited. c) When the gap measurement is carried out according to the provisions of 8.3.2, the size of the opening or crack of the specimen reaches the provisions of a) or b) in 8.3.2. d) Collapse.
10 Test report
The test report should include the following contents:
a) Name of the test entrusting unit;
b) Name of the manufacturer and product model specifications, c) Sample delivery form:
d) Standard number;
e) Test date;
f) Test data;
g) Observation record;
GB17428-1998
h) Schematic diagram of the test piece structure, material, technical data, installation and other relevant instructions; Test conclusion;
j) Signature of the test host and the person in charge of the test unit, and seal of the test unit. 322
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.