Oil-filled rotary screw compressors are among the most reliable air compressors available today and are designed for maximum efficiency over long operating periods. Whilst it’s true that no mechanical system can ever be guaranteed 100% failure-proof, the most common issues that can affect the performance of a rotary screw compressor arise due to a lack of care and preventative maintenance on the owner’s part. Failure to replace the oil/air separator in accordance with the manufacturer’s instructions, for example, will eventually lead to the filter becoming clogged or saturated with oil resulting in compressed air that is contaminated with oil and a loss of system pressure. Left unattended, the compromised air/oil separator could fail completely, flooding your entire air compression system with oil.
As part of its normal operation a rotary screw compressor will draw in large volumes of air which contains water vapour. The process of compressing this air produces a significant quantity of condensate (water) which is normally drained away automatically. However, if this drainage system isn’t maintained it may malfunction, resulting in the production of ‘wet’ rather than dry compressed air and the possibility of water collecting in the compressor’s air receiver and pipes.
If an oil-filled rotary screw compressor simply gives no pressure at all, the cause may lie with a faulty pressure switch or a dirty or broken check-valve; this latter component may be removed for cleaning and to check that the spring inside is not damaged. Whether it’s the pressure switch or the check-valve that’s at fault, a replacement for each should be easily obtainable.