Air dryer for pneumatic power hammer?

[metalmoron]

How important is it to have a an air dryer for your pneumatic power hammer? Id like to keep my hammer in as nice condition as possible of course. Though im finding it a bit hard to shell out the money for an air dryer that may or may not make a difference. Any advise would be helpful.

[John Larson]

The purpose of an air drier with an air hammer is most important in cold weather when condensate can freeze the valves and cylinder. And then hurt the synthetic rubber rings and seals. And promote rust inside in the winter, especially between the piston faces and the cylinder cap insides. There is a simple solution. Use air tool oil with an antifreeze additive. Ingersoll-Rand sells it by the gallon on their web site. There are other brands for sale on the internet. Carpenters in cold climes have been coping with this air tool problem for a very long time. The old time solution, I was told by a Detroit smith, is 50% air tool oil and 50% alcohol. I don't like alcohol's behavior, so I'd use glycol. One valve manufacturer recommends straight glycol. The whole quest is no ice/rust and oil for lubrication. Even with an air drier the use of antifreeze oil in cold climates is smart. And, once you start using an oil do not stop. Valves do not like dry.

[gearhartironwerks]

I think it's imperative as well as is an oiler following the dryer to the hammer. Both should be mounted fairly close to the hammer, but preferably not on it as the vibrations can be destructive. My suggestion would be to have 1/2" ports in, between the units, and out to the hammer.
John

[JNewman]

I have never had a dryer on my hammer and have not had a problem. Grant used to mention there was no sense in using a drier on compressed air on steam hammers. That you would lose energy by using a dryer.

[gearhartironwerks]

I don't know about a steam hammer. I'm thinking of the multitude of air hammers (Kinyon style) that I believe need air/oil filters to operate to their optimum potential.
John

[monstermetal]

Yeah "Air Hammer" is a pretty broad term.. Technically a Nazel is a Electro-pneumatic air hammer.... A steam or converted hammer as long as its got lots of oil I dont think water would hurt a bit but I dont think that is what he is asking.... On a utility air hammer that uses a pneumatic cylinder and pneumatic valves I would sure bet you would want to keep the water out... Water does not compress and I would guess would make everything sluggish and gooky when mixed with oil... John is the expert... ( Sorry John, I was talking about the other John but your a smart fella too) His comment about cold weather and stuff freezing makes sense to me

[metalmoron]

Thanks for all the advise fellas. I think im going to go ahead and get one just so i know my Baby will be safe.

[timgunn1962]

"Air dryer" is almost as broad a term as "air hammer".

It can cover coalescing filters, refrigerant dryers, dessicant dryers, membrane dryers, deliquescent dryers and probably more I've not come across.

Unless you have a severe climate, or an unusual usage pattern for your hammer, a good coalescing filter with an autodrain will probably get the job done.

I'd recommend you fit it as close to the hammer as possible, but before the regulator. That way you get the air as cool as possible, making as much condensate as possible, before the coalescer, which will remove all the liquid water and fine mist droplets. The regulator will then reduce the pressure, which has the effect of drying the air, to your working pressure. If you use one, the lubricator goes just downstream of the regulator.

Make sure the bowl on the coalescing filter has a proper float-operated autodrain, not a semi-autodrain. The semi-autodrains only drain when the pressure is released; no good if you work for any length of time.

Do some reading up on the subject and talk to a few pneumatic equipment suppliers before you pull the trigger. Things can easily get unnecessarily spendy.

If a coalescer will get the job done, shop around. The big-name stuff is good, but it ain't rocket science and it ain't new technology. There's some very good stuff coming from the far East at very low prices.

[ptree]

I personally would never ever run a pnuematic hammer designed for compressed air without some form of water seperator. In my part of the US a air compressor running at about 5Hp will have lots more condensate than you think. Condensate KILLS valves and other pnuematic devices.
Now as noted a dryer is often thought to be a Refrigerated dryer in my world, industry. We shoot for a -40f dew point and that eleminates most of the problems we see. In a home shop a reefer dryer is costly. A good sized tank beyond what the compressor has is a good first defense. Then to a regular filter water seperator that will catch the gross droplets and protect your coalescing filter from early clogging and then into you regulator if needed and last to a lubricator. The lubricator needs to be as close to the end use as feasible to allow the oil mist to stay entrained in the air. At the exhaust another cheap filter water seperator with an exhaust muffler will kill most of the noise and catch most of the oil mist.

Steam hammers converted to air are very different beasts. The hammers we had at VOGT were designed for 145psi wet steam. Wet steam has entrained droplets of water along with the injected "Heavy Steam Cylinder oil" Big clearances in the steam chest and valve box, and droplets are not nearly as destructive.

When I say filter water seperator above I refer to a 5 micron element with a centrifical vane set to spin out the bigger droplets.

I am NOT a fan of any auto drain on the market finding them all to be failures waiting to happen with the exception of the motor operated ball valves with timers.

I am a fan of Parker's "Micro-Mist lubricators" finding them the best when I tested and then installed several hundred at VOGT.
I tend to like to go at least one port size bigger on all F-R-L components as they are usually pretty low Cv and restrict the flow.

Remember that you always pull drops off the main from the top, slope the air mains to a drain, and have a drip leg at the drop end where you connect to the device.

NEVER use plain PVC pipe for air lines. It gets brittle and explodes. I prefer that old standby black iron pipe. I prefer ball valves for air lines over all other types. I do NOT like the components with O-ring sealed connections for air lines, they soon leak. I prefer pipe dope over pipe tape hands down, the tape is usually mis-applied and then shears off and is in you valves locking them up.

I NEVER reccomend any of the patent medicine air tool oils, instead I reccomend plain ATF. It is cheap, easy on seal materials, has a great wear package, a very low pour point and did I mention way cheap?

I prefer Poly-gycol coolant in My screw compressors as it is not only very environmentally friendly compared to oil, it makes the compressors last longer and makes the condensate less "Sticky"

Ptree who once managedthe powerhouse for a 42 acre factory compound with 3900 Hp of compressors sending air all over to the manufacuting plant as well as the 2 Gas fired 800 Hp (82,000#/hour) boilers for the steam drop hammer that had 28 hammers up to 25,000#. We estimated 300 miles of air mains and who knows how much secondary air piping.

In the valve shops before I had the powerhouse I also did all of the pnuematic and hydraulic test machines. So i may have a little experience with air equipment.

[r smith]

Thanks Ptree :)

[Dillon Sculpture]

Here is a shot of my filter/water separator. For the size I needed the whole unit was a couple thousand new, the filter element was a couple hundred, so I made one. It's a old 6" Randolph fire exteingusger with some pretty cool graphics to boot! I also have a reserve tank after the compressor that seems to catch most of the pollutants. Interesting the air is quite chilly when it exits the hammer. Oh yea, does that gauge read over 100 psi! :wacko:

[John Larson]

I personally recommend copper instead of black iron pipe. The inside of the iron pipe ALWAYS rusts SOMEWHERE in the the system and that fouls up valves. One replacement valve can pay for a lotta copper over iron price differential.

[gearhartironwerks]

What about galvanized pipe? The price of copper is a lot more. Here on the coast, galvanized is readily available for reasons you can imagine. Black pipe is virtually non existent locally. We do however, use black pipe for forging, and even that is sometimes difficult to obtain, even from our flatland distributors.
John

[ptree]

Galvanived pipe nd fittings are coated BEFORE they are threaded, and so if corrosion is a problem, the corrosion will start there. I personally don't like/recommend copper tube as it is very soft and thin and easy to damage/cut.
If you are doing a good job with condensate removal at the compressor, the pipe will not degrade to any extent. Remember to slope the pipe to a drain, pull the drops off the top of the pipe and you will have decades of good sevrice. Don't forget that drip leg and filter at the using device.
I have worked in many factories, and all were piped in plain black iron. We considered schedule 10 stainless with crimped Vitolic fittings at the 6.5 acre shop I was owners rep for when built. The cost was a wash versus black iron as the stainless and fittings were higher but the labor less. But the thought of o-ring seals at every single joint in a piping system I thought I would have to maintain for the next 20 years had me choose black iron.

This really is not rocket science. Use a big tank close to the compressor to allow the hot wet air time to cool and the water to precipatate, run the air lines in a size that is big enough to maintain industry rated "Reasonable" flow rate. Slope the piping to allow water to drain back to a drain, take the drops off the top of the runs to prevent condensate draining to the use device, use a drip leg and filter at the device.
You will find the same info in the Machineries manual back to the very early editions. That is because it works, and is the most practical and economical. That is how you will find all the old air hammers that used air from a plant compressor piped, and they ran and ran and we still are finding and using them.

Really care about those valves and want to get them to last? choose your air line oil carefully, don't use teflon tape and use a decent 5 Micron (Micro-meter) rated filter followed by a coalescensing filter. In reality, with the above suggestions the seals will age fail before they fail from use or condensate.

[John Larson]

I sell to ordinary people, not plant engineers. I will continue to recommend copper. EVERY customer I've had using black iron pipe, typically installed before they buy my hammer, has had internal rust problems.