Frequently Asked Questions about Quality Inspection of Screw Air Compressors
I. Related to Quality Inspection Standards
1. Which standards are the quality inspections of screw air compressors based on?
The quality inspections of screw air compressors are mainly based on the international standard ISO 1217 "Acceptance Tests for Positive - Displacement Compressors", which stipulates the methods and accuracy requirements for performance tests of positive - displacement compressors. At the same time, it refers to the national standard GB/T 3853 - 2016 "Acceptance Tests for Positive - Displacement Compressors" to standardize key performance indicators such as air displacement, discharge pressure, shaft power, and isothermal efficiency. In addition, industry standards such as JB/T 6430 - 2014 "General - Purpose Oil - Injected Single - Screw Air Compressors" make specific provisions on aspects such as the oil - injection system, noise, and vibration for different types of screw air compressors.
2. Are there differences in quality inspection standards for screw air compressors in different application scenarios?
Yes, there are differences. For example, screw air compressors used in the food and pharmaceutical industries, in addition to meeting conventional performance indicators, have extremely high requirements for the quality of compressed air. The oil content, particulate matter content, and microbial content in the compressed air need to be strictly controlled to ensure compliance with relevant industry hygiene standards. While ordinary screw air compressors used in industrial production focus more on meeting basic performance requirements such as pressure, flow rate, and energy consumption.
II. Related to Quality Inspection Processes
1. How many quality inspections are carried out during the production process of screw air compressors?
There are usually three key quality inspections during the production process. Before production, spot - checks are carried out on all incoming parts to ensure the quality of raw materials. During production, process inspections are carried out at important assembly links, such as checking the meshing clearance after the assembly of screw rotors. After production is completed, a final inspection of the whole machine is carried out, including performance tests and appearance inspections.
2. What items are mainly tested in the whole - machine performance test?
The main items tested include discharge pressure, air displacement, power consumption, noise, and vibration. The discharge pressure needs to reach the rated pressure marked on the equipment nameplate. The air displacement should meet the gas - using requirements under different working conditions. The power consumption needs to be within a reasonable range to ensure the energy - saving performance of the equipment. The noise and vibration levels must comply with national standards to ensure the comfort of the working environment.
III. Related to Testing Equipment
1. What are the key equipment for testing screw air compressors?
The key equipment includes flow - measuring devices, such as sonic nozzles and orifice plate flowmeters, which are used to accurately measure the air displacement; pressure sensors, which monitor the discharge pressure in real - time; power analyzers, which measure the input and output power of the motor; noise testers, which measure the noise generated during the operation of the equipment; and vibration analyzers, which detect the vibration amplitude and frequency of the equipment.
2. How often are these testing equipment calibrated?
To ensure the accuracy of test data, key testing equipment such as flow - measuring devices, pressure sensors, and power analyzers are generally calibrated once a year. Noise testers and vibration analyzers can be calibrated every six months to one year according to the actual use frequency and accuracy requirements.
IV. Related to the Handling of Non - Conformities
1. How will non - conformities be handled if they are found during quality inspections?
If the spot - checked parts are non - conforming, the batch of parts will be rejected, and the supplier needs to provide qualified products again. When the whole - machine performance test is unqualified, the cause of the failure will be analyzed first. If it is an assembly problem, re - assemble and debug; if it is a part quality problem, replace the qualified parts and conduct the test again until it is qualified.
2. What is the traceability process for non - conforming products?
Through information such as production batch numbers and part numbers, trace back to links such as raw material suppliers, production teams, and assembly workers. Analyze whether it is a raw material quality problem, a production process problem, or an assembly error, so as to take targeted improvement measures to prevent similar problems from recurring.
