General Regulations for Ventilation Pipe Inspection
1. The quality inspection of air duct shall be carried out according to the material, process, type of air duct system, air leakage grade and the gas transported. The air leakage grade and allowable air leakage amount of air duct shall conform to the requirements of Table 1.
Table 1 Grades and Permissible Air Leakages of Air Pipes
Note: 1. The air duct system is divided into 5 grades according to its use type. The maximum air leakage of medium pressure duct should not be greater than that of B grade, the maximum air leakage of high pressure duct should not be greater than that of C grade, and the special requirement duct should not be greater than that of D grade.
(2) The air leakage of smoke exhaust, dust removal and low temperature air supply system shall not be greater than Class B.
(3) The air leakage of grade 1-5 purifying air-conditioning system should not be greater than grade C.
(4) Class E is only used in virology laboratories and other special purpose ducts;
_, P is the static pressure in the duct, the unit is Pa.
2. Outsourcing finished air ducts shall provide corresponding test certification documents such as pressure strength, air leakage grade and air leakage amount according to the type of air ducts. The test certification documents shall not exceed 3 years, and the performance test items of air ducts shall conform to the requirements of Table 2.
Table 2 Item sheet for air duct performance test
Note: If the name of the duct type is indicated, it means that the test item is applicable only to specific types of ducts.
3. After installation of the main air duct of the air duct system, the air leakage of the main air duct system should be inspected before connecting the tuyere and branch air duct.