Auto Drain valves
Your document refers to auto drains as applying to industrial compressed air systems.
A question on a general petrol station site that supplies air to a carwash - pneumatic rams (cylinders) and controls - air driven dosing (metering) pumps etc. with a tyre gauge and air operated LPG valve - would this type of installation need an auto drain on the air receiver?
At this point the receiver is drained manually once a week by site staff and compressor is often poorly located distant from the main air user - the carwash - up to 50 metres away. Carwash is heavily used on the weekends. Size of compressor is from 3 to 10HP.
Bill answers...
Hello Ross.
Usually industrial compressed air systems are high volume compressed air users, and the need for auto drains becomes more important as a result, and the water generated can't easily be handled by a "once a week" draining.
Having said that, all compressors generate water. Follow this link to find out why if you're not already aware.
So, will your petrol station benefit from an auto drain on the receiver?
Simple answer is, yes.
Because, if any of the systems being supplied by that compressed air can be negatively affected by free water and water vapour condensing in them, ridding the system of water can only help.
Having supplied rams (cylinders) to car wash OEM's in the past, my recommendation would be to use stainless steel. Many OEM's will not, finding the cost of them prohibitive. Over time, mild steel cylinders will rust, the barrels will score, and cylinders will ultimately cease to function as compressed air bypasses the shredded seals inside the cylinder.
And so it goes with other equipment that degrades from water, dirt slurry, and varnish from compressor oils that reach that equipment.
Auto drains are recommended at the receiver, at drop lines from the main supply ( follow this link for compressed air plumbing tips ) and, depending on the amount of water reaching the equipment, even on the filters that you've installed just before that equipment.
Long supply mains are very prone to generating lots of water through cooling and condensation from the hot compressed air out of the compressor.
Hope this helps....
Cheers.
Bill
