What kind of certification does environmentally friendly oil-free air compressors need to pass to prove their oil-free performance?

A. Inspect reinforced gas piping B. Replace the leaking valve C. Check or replace air valve D. These are all answers: D. all of the above are

A. Permanent magnet frequency conversion, centralized gas supply, energy management B. Home use, commercial use C. Oil and gas, construction, logistics D. Manufacturing, oil and gas, construction Answer: A. Permanent magnet frequency conversion, centralized power supply…

A. 5% B. 11% C. 20% D. 30% answer: B Analysis: For every 1000 meters increase in altitude, the air density drops by about 11%.

A. Increase exhaust temperature B. Avoid dirt that leads to reduced efficiency C. Increase noise D. Shorten equipment life Answer: B Analysis: Cleaning the cooler can prevent the accumulation of dirt and maintain efficiency.

A. A few hundred yuan to several thousand yuan B. Thousands of yuan to tens of thousands of yuan C. Tens of thousands to hundreds of thousands of yuan D. Hundreds of thousands of yuan to several million yuan Answer: B. Thousands to tens of thousands of yuan