air compressor water trap

[jniolon]

Hi Jon and all

just finished fabbing and install on a air compressor water trap... here's the article on it...

http://jniolon.classicpickup.com/com...rwatertrap.htm

thought it might help someone out

later
john

[DIYer]

Thanks jniolon! We've added your Air Compressor Water Trap to our Air Compressors category,
as well as to your builder page: jniolon's Homemade Tools. Your receipt:

Air Compressor Water Trap by jniolon

tags: air compressor

[G.Paul]

It is not recommended to use cooper pipe and pvc pipe for air supply lines. The best air supply lines are black iron pipe

[kenbee]

Hi Jon and all

just finished fabbing and install on a air compressor water trap... here's the article on it...

http://jniolon.classicpickup.com/com...rwatertrap.htm

thought it might help someone out

later
john

Nice plumbing job, it is my experience that hot air can carry much more moisture than cold air, so with that understanding, I think the trap will be more effective on the outlet end of the tank, considering that the large area of the tank will help cool the air, so considerable moisture will drop out in the tank, and the remaining moisture will be mostly caught by your after-cooler/trap. I believe the drip legs in each section of the trap could be made more effective by using a tee at the bottom of each leg in the direction of air flow so any water will already be going in the direction of the drip leg, and a longer drip leg would hold the water away from any turbulence so it would not get picked up by the air flow. The drip leg could also be connected by a tee at the end of the loop bottom before the air flow turns to go up, with the tee horizontal so the air flow drives the water to the tee and out a short pipe ended with a turned down elbow to the drip leg. You could also wire a fan to blow on your trap when the compressor is running.

seeing the nice job you did on the plumbing, the suggested changes should not bee a big deal. (my experience is in inventing pneumatic air tools as a consultant, and have dealt with water in compressed air systems for years)

Regards
Ken

[G.Paul]

Water is not a critical on air tools but not desired. Air with moisture for painting is a totally different problem. Moisture can not be totally removed with drip legs no matter how may you have. Yes the plumbing looks good the pipe used can split under high pressure as well as the solder joints. A air dryer is the answer. Yes black pipe is a lot lot more work but it is save

[kenbee]

IF YOU PLAN TO USE PNEUMATIC TOOLS, THE TYPE OF TOOL IS IMPORTANT. UNLESS YOU ARE USING ONLY AN ARTISTS AIR BRUSH, OR AN UPHOLSTERY STAPLER, DON'T BOTHER WITH ANYTHING THAT DELIVERS LESS THAN 4 CFM (CUBIC FEET OF FREE AIR AT 90 PSI -POUNDS PER SQUARE INCH-PER MINUTE).

AIR TOOL CFM USAGE RATINGS ARE BASED ON INFREQUENT USE, LESS THAN MAYBE 5 SECONDS TO 2 MINUTES AT A TIME. INDUSTRIAL IMPACT WRENCHES ON AUTOMOTIVE ASSEMBLY LINES ARE EXPECTED TO INSTALL OR TIGHTEN A NUT IN 5 SECONDS, AND THE OPERATOR TYPICALLY HAS ABOUT 46 SECONDS TO TIGHTEN MULTIPLE FASTENERS. AN AUTO REPAIR SHOP MIGHT REMOVE OR TIGHTEN 5 NUTS PER WHEEL IN LESS THAN TWENTY SECONDS, UNLESS SEVERELY RUSTED, THEN TAKING CONSIDERABLY LONGER. ON THE OTHER HAND, IN DRIVING LONG LAG BOLTS TO FASTEN FENCE RAILS MAY TAKE HALF A MINUTE OR MORE. AIR TOOL MANUFACTURERS RATE AIR CONSUMPTION FOR SHORT INTERMITTENT USE, SO THE IMPACT WRENCH, FOR SIZING A COMPRESSOR CAPACITY IS RATED AT 4 CFM,WHILE THE TOOL, IF RUN CONTINUOUSLY MAY CONSUME 15-20 CFM. A SANDER RATED AT 4 CFM MAY NEE7 7-15 CFM FOR CONTINUOUS SANDING, SO A 4 CFM IS USELESS.

A HIGH QUALITY AIR COMPRESSOR, EXPENSIVE, 2 STAGE, SHOULD DELIVER 4 CFM OF FREE AIR AT 90 PSI PER 1 HORSEPOWER ELECTRIC MOTOR OR 1.4 HORSEPOWER GASOLINE OR DIESEL ENGINE BECAUSE THE ENGINES ARE LABELED AT MAXIMUM HORSEPOWER BUT ARE USUALLY RECOMMENDED TO NOT LOAD THEM MORE THAN 85% FOR CONTINUOUS DUTY.

SINGLE STAGE AIR COMPRESSORS RARELY DELIVER MORE THAN 3.5 CFM PER HORSEPOWER, AND ARE MUCH LESS EXPENSIVE. IN THE 1970s I RE-MANUFACTURED VOLKSWAGEN AIR COOLED ENGINES, TWO PER 8 HOUR DAY ON A MINI PRODUCTION LINE, USING A $250 7.5 CFM AT 90 PSI SINGLE STAGE 240 VOLT COMPRESSOR. I USED 1 IMPACT WRENCH PER SOCKET, ONE AIR RATCHET PER SOCKET, 1 AIR HAMMER PER CHISEL OR OTHER ACCESSORY, ONE AIR DRILL PER DRILL BIT OR CUTTER FOR REPLACING AND REAMING O KNURLING VALVE GUIDES AND ONE DRIVER FOR EACH VALVE CUTTER, PLUS A SAND BLASTER, 3 DIFFERENT WIRE WHEELS, A DISK GRINDER, AN AIR GRINDER WITH A CUT-OFF WHEEL, AND 2 SCREWDRIVERS FOR PHILLIPA AND SLOTTED HEAD BITS . THERE WAS NO WASTED TIME CHANGING SOCKETS, ETC.

NOW, BECAUSE I OFTEN WORK OFF SITE, I USE 4 TO 5 CFM SINGLE STAGE 120 VOLT POWERED COMPRESSORS. THEY TYPICALLY COST ABOUT $100 ON SALE, I DON'T HAVE TO FIND A 240 VOLT CIRCUIT, THEY ALL HAVE DIFFERENT CUT-IN PRESSURES SO AS NOT TO USE TOTAL STARTING CURRENT AND I CAN PLUG THEM INTO DIFFERENT CIRCUITS IN A HOUSE, AND IF ONE QUITS, I'M NOT OUT OF BUSINESS FOR THE REST OF THE DAY AND THEY ARE EASY TO LOAD INTO A VAN OR ON A TRUCK. A 120 VOLT COMPRESSOR CAN RUN ON A 1800 WATT GENERATOR. 2 0N A 3000 WATT GENERATOR. IF THERE'S NO ON SITE ELECTRIC POWER, I BRING 2 GENERATORS, SO I WON'T HAVE TO QUIT IF THE GENERATOR DIES. I ONLY ONCE HAD A COMPRESSOR QUIT ON THE JOB AND IT WAS NO BIG DEAL, I FIXED IT THAT NIGHT.

A HOME SHOP USING ELECTRIC AND CORDLESS TOOLS CAN GET BY ON ONE 4CFM COMPRESSOR. KEEP IN MIND THAT A ONE ELECTRIC HP COMPRESSOR TYPICALLY DELIVERS 3-4 CFM AT 90 PSI, WHILE A ONE HP AIR MOTOR WILL USE 25-27 CFM OF AIR AT 90 PSI.

[Horse Heaven]

It is not recommended to use cooper pipe and pvc pipe for air supply lines. The best air supply lines are black iron pipe

I agree regarding PVC. When PVC pipe fails under pressure, it can produce shrapnel with long sharp points. And, PVC degrades over time due to oxidation, UV exposure, and fatigue. PVC has a very limited thermal range of operation.

While copper (or ANY) pipe might fail, it is rated well above the pressures and temperatures associated with normal compressed air. This is evidenced by its extensive use in HVAC systems. Proper solder joints are every bit as strong as the pipe, especially with regard to burst strength. When copper pipe does fail, it typically fails by splitting the forming seam, first evidenced by pinholes, then a very gradual leak. A completed structure, such as the one displayed by the OP, can easily be hydrostatically tested by filling it with water and applying pressure using a hand-held hydraulic pump. (Home-made version would be a brake master cylinder with a lever-handle.) Put a pressure gauge in the circuit to avoid destroying your creation. A suggested safety margin would be 1.75 times the intended system maximum.

Black iron or galvanized pipe might be advised due to its extreme burst strength, but has a few drawbacks: The formation of rust scale can be a problem, and it's not uncommon for threaded joints to seep air even when determined to be water-tight. If a leak develops post-installation, it can be challenging to chase back the series of joints to allow tightening, especially where Ts are employed.

All of my comments are based on first-hand experience.

[Horse Heaven]

I agree with kenbee's suggestions.

I have a portable dryer of this general type that I built in 1984. It has M/F couplings located on the top, with a petcock at the bottom of the drain. I used it for years as the penultimate step (dessicant/filter on the spray gun) when painting cars out of my rental garage. It was sized to be stood in a 33 gallon garbage can, filled with water and a few bags of ice. I cracked the petcock to drain the condensate... a small stream of bubbles confirmed there was no water accumulating. My design had a single down-leg and three up-legs, resulting in increased heat-exchange surface area and much slower air-velocities leading to the outlet. Even using it "dry", it would drip a nice puddle of water on the floor under it if the day was humid, and, running in ice-water, it must have been very efficient. This setup worked FLAWLESSLY. Never had a drop of water reach my spray-gun. I still loan it out to DIY painters.

I have since evolved, and now have a commercial air-dryer installed in my facility, but have also incorporated several elements of my original old design into the plumbing exiting my dryer. Upstream from the dryer, I have an accumulator tank (20 gallon tank from an old portable compressor) with drain, a 3/4" galvanized, 12' vertical down-leg into a drain trap with purge valve, followed by a 2-1/2" galvanized 12' vertical up-leg leading into the dryer. The air entering my dryer is already mostly dry, as evidenced by the lack of condensate that collects there. Every tap into my building's air system has a trap and drain leg, and every leg from the overhead main exits the main from the top, then 180s to the drop. Each tap is preceded by a quick-connect filter and sediment bowl, and regulator, both with support brackets, as well as a hose support (made from old engine pulleys.) The main is 3/4" galvanized, and has a 3/4" ball valve straight out the termination of the run for blow-out.

My air is clean and DRY.