Loud auto air drain valve

[Janger]

I finally got my auto drain valve hooked up to my compressor. I've set it for 30 minute intervals and six seconds. It works. It's LOUD. 95db loud says the phone app. It's so loud I have to put my fingers in the ears. Anybody got a quick easy solution to this?

 

[Brent H]

Build a muffler out of a piece of 3” pipe -

Some kind of concept to allow the air to expand a bit before it exits the bleed

 

[Dabbler]

wow. to think I almost bought one.

Seriously - add a valve downstream and cut down the flow rate. You only need a couple of cups of air to bleed away the moisture.

 

[Janger]

The muffler is a good idea.

but today I shut the ball valve nearly off and shortened the time to 1 second. Now it’s 75db much more tolerable. Hopefully water still comes out. Thanks guys.

 

[kevin.decelles]

I bought one after seeing John's, got it from amazon for $30. Noiser than hell too. I can say though, that it is doing the job as my air dryer/filter system has looked better since putting the drain on (less spooge and buildup from the dryer drain). I was pretty regular with opening the valve manually, but the automated bleeder is pretty slick.

 

[Janger]

Dabbler and anyone buy one. Just turn down the flow as you suggested and it’s ok now.

 

[Chicken lights]

Hopefully it doesn’t plug up the ball valve with it being partially closed.

Anyone running an air dryer/filter should have the dryer mounted as far away from the compressor as possible.

 

[Alexander]

Attach one of these single trumpet air horns. That will fix it

 

[CalgaryPT]

I finally got my auto drain valve hooked up to my compressor. I've set it for 30 minute intervals and six seconds. It works. It's LOUD. 95db loud says the phone app. It's so loud I have to put my fingers in the ears. Anybody got a quick easy solution to this?

I've had various iterations of these over the years John, and eventually gave up as they either clogged or failed in time. The muffler in @Brent H 's post makes sense...it is the same principle as an in-house canister vac uses. However, I found the best solution was a simple sponge affixed to the end of the drain pipe. It attenuates the noise AND prevents the rusty water going everywhere. That's all I use now, without an automated drain value.

To be frank, as much as I loved automating this task, I no longer do it even regularly. I put a scope into the inspection hole on my Campbell Hausfeld 60 Gal a year or so ago and was shocked at what good condition it was in after 20 years. I got my money's worth. I had an uncle in Florida years ago who used to get more than a cup every day out of his.

BTW there are some posts online about these. You need to be careful if you leave your compressor on 24/7 like I do. If the valve clogs and gets stuck, you can burn out your compressor or motor as it will run continuously because the pressure switch won't ever activate to shut off the motor. The old NOVA service centre on Blackfoot Trail (before they moved to Airdrie) had automated drain valves on theirs, but always in conjunction with some kind of duty timer so if the drain clogged in the open position the compressor wouldn't run until it burnt itself out.

 

[Janger]

I’m building a muffler out of another project that didn’t go anywhere. This black cylinder I printed a while back and today I printed this flange and threaded it npt 1/4”. I had to buy a tap because Fusion unbelievably does not model tapered threads yet - so you can put them in the drawing but they only 3D print as a simple hole. This flange will take the air drain hose and I’ll stuff the cylinder with old tshirts. I’m printing and glueing the ends shut with a printed disc. The lid is being glued under that hunk of steel.

 

[Alexander]

Cool that looks great. Has anyone ever seen a tank rated for wet service? They are not uncommon in industry. The one I saw last year was stainless so it wouldn't be affected by moisture

 

[YYCHM]

Jeepers how big is your 3D printer and how long did that take to print?

 

[Janger]

A stainless air tank interesting. Sounds pricey. Sounds medical or lab like. Was this at a shop?

 

[Janger]

The bed is only 25cm x 25cm. It’s a prusa mk3. Standard stuff. This is 6” or 15cm in diameter. It did take quite a few hours probably 20 or so.

 

[Janger]

Printing lid. See pen on bed for scale.

 

[PeterT]

John, my hunch is that stuffed fabric could be improved upon as a noise insulating material. If it sees moisture, the material will get grotty and anything saturated loses noise dampening pretty quick. Mufflers typically have combinations of impingement plates or tubes or perforated weirs so sound waves are ideally redirected & reflected internally. And some kind of insulation that is made from flexible cell membranes of mostly air pockets (foams, glass mat etc.) I think these are for the most part water proof because only the exposed cells are 'open', the rest are closed like bubbles. They have porosity but no permeability. I'm not quite sure of the flow path of your canister but maybe you could print integrated annular rings sized for sheets of inserting standard acoustic foam. As long as there is no high temp involved? https://www.amazon.com/acoustic-soundproofing-insulation-soundproof-dampening/dp/B07DFS4ZVJ?th=1

Mufflers are a bit of crazy science. Our ears perceive noise in different ways.

When I had my screamer compressor I hooked it up to a PVC pipe with annular foam tube. It worked but noise reduction was proportional to volume. It wanted a rather large snorkel & still that dang slapping diaphragm noise could still be heard. Now I always read the dB rating of machines.

 

[Alexander]

A stainless air tank interesting. Sounds pricey. Sounds medical or lab like. Was this at a shop?

It was in a manufacturing facility. The air tank is so the compressor doesn't load and unload as often. In this case they have the air dryer after the tank.

 

[CalgaryPT]

John, I think you are the right track. If it's any help I once took apart my muffler for the central vac in my house to see how it was made (see pic). I recall the airflow was just around a few baffles, and just used foam as the attenuator (like @PeterT said). It's glued together now otherwise I'd take it apart to show the inside, but I seem to recall the foam was rolled up so that it was inline with the airflow. In other words, it didn't completely block the flow within the baffles. If you imagine a piece of paper, rolled up loosely, then inserted into the chambers made by the baffles so that the air flows within the folds of the paper like a bunch of pipes that fit inside one another, that's what it looked like.

Playing with these designs is fun as mentioned above. A great tool is one of those cheap Dr Meters on Amazon. They are about $30 and are really helpful because as mentioned, sound is kinda weird.

But you've sure got the right tool with that 3D printer of yours to experiment. Let us all know when you've got a finished design.

 

[Janger]

It’s much quieter. 62db says the phone app. I can stand next to it and it’s fine. I stuff a roll of foam inside the can and separated each layer with foam spacers. Drilled two little holes in top to let the air out. I need to add drain holes on the bottom. The threaded rod holds the lid down and presses on the foam. Simple and effective.

 

[CalgaryPT]

It’s much quieter. 62db says the phone app. I can stand next to it and it’s fine. I stuff a roll of foam inside the can and separated each layer with foam spacers. Drilled two little holes in top to let the air out. I need to add drain holes on the bottom. The threaded rod holds the lid down and presses on the foam. Simple and effective.

Nice work John.