There is quite often a misconception about compressor regulators that we will try to dispel here, as well as giving you lots of information about how to best use your compressed air regulator.
While probably not all, most air compressors that have a tank will come equipped with an air regulator. It is typically located on the discharge line from the tank, upstream from the discharge coupler, which is the coupler into which you plug the connector on your air hose. Depending on the make and model of your air compressor, your compressor regulator will look something like the one in the image.
Your compressor regulator may be a different color. Your regulator may be bigger or smaller, it may have a smaller or larger air gauge or the air gauge may not even be directly attached to the regulator, your regulator adjustment knob may look different, yet all air regulators are basically similar in function to the one shown.
Using Compressor Regulators
Using the regulator is pretty straightforward. If you turn the regulator adjustment knob in a clockwise direction, that normally elevates the regulator pressure setting. Turn the knob counter-clockwise and the regulator setting is reduced.
Whatever pressure is displayed on the regulator gauge – not the tank gauge since your compressor typically has two gauges – is the pressure of the air stream exiting the discharge coupler into your air hose.
Some regulator adjustment knobs lock by either depressing them or pulling them out. If you find that you cannot turn the regulator adjustment knob, try pushing down on it or pulling it up. If it has a built-in adjustment lock, that should unlock it.
About Compressor Regulators Misconception
The most significant misconception about compressor regulators is that they can raise the air pressure!
If your tank pressure is 100 PSI for example, you can increase the discharge pressure by turning the knob in a clockwise direction. If you try to dial the pressure up past the tank pressure of 100 PSI the regulator gauge needle will stop at and display the tank pressure of 100 PSI, and that’s the pressure that will be exiting the discharge coupler to the air hose.
The air regulator can only adjust pressure down. No air regulator can adjust the pressure up past whatever the pressure is in the tank or air mains.
What Good Are Regulators Then?
The compressed air regulator is an important device. Why? Because it allows you to dial the pressure down to the the absolute minimum required by the air tool you are trying to operate.
Running your air tool at the minimum operating pressure extends the life of the air tool, reduces the amount of air used – which cuts down on energy cost to compress the air – and reduces the cycle frequency of the air compressor, which has positive ramifications for the compressor life and maintenance cycle.
Always adjust the air regulator pressure setting to the minimum pressure level required to operate any of your air tools.
Can You Have Multiple Air Regulators?
Absolutely you can. Many industrial plants plumb their compressed air up to a ceiling mounted air main that circulates the plant. The air pressure in the air main is typically the highest pressure that the plant compressor can generate.
Drop lines are installed from the air main down to the shop floor to supply compressed air to various pieces of equipment. Each machine or piece of equipment may have a different minimum operating pressure, so there will be a regulator (and typically a filter too) installed just before each piece of equipment so that the pressure can be set to the optimal performance level.
So too, in your home shop you can adjust the pressure for your air line on the regulator in the discharge line from the tank, and if desired, you can install air regulators anywhere else in the line to be able to further adjust the air pressure if you have multiple uses of compressed air.
Compressor Regulator Maintenance
For most of us DIY type folks with home or small shop air compressors, the regulator that came with the compressor will be a cheap one, mass produced in some foreign land for pennies each, and sold to the compressor assemblers for not much more than that, we expect.
The diaphragm inside the regulator upon which the compressed air presses to control the downstream pressure will crack in time, through high cycle exposure, from contamination of the diaphragm by compressor oils, debris in the air stream, or drying out of the regulator diaphragm over long periods of inactivity. If the regulator diaphragm cracks, your regulator will leak all the time.
The regulator gauge is cheap as well, and over time the innards corrode, or an impact might shatter the gauge-face cover.
Industrial air compressor regulators typically have a good supply chain of spare parts. They are expensive enough to warrant dismantling and repairing rather than tossing them out.
The typical DIY compressor air regulator does not enjoy a good supply of parts. With the price of a new regulator being in the $20 – $30 range, it’s hard to justify buying a kit (if you can find one) for almost that amount of money and spending a couple of hours tearing the regulator down and trying to get it working again.
In other words, the low end regulators are basically disposable when they fail.
You can replace the gauge on a regulator for around $7 – $10, however. If it’s the gauge that goes, do get a replacement.
If the regulator starts to leak, sure, try to find a diaphragm for it and fix it if you can. For us, it’ll be time for a new compressor regulator at that point.
Since most replacement regulators come equipped with a display gauge, if the old gauge is still working, keep it for a spare.
Got a question about your air compressor regulator? Use the comment form below to ask it, and we’ll help if we can. If you see a question about air regulators here, add your comment if you can help. Only questions and comments about compressor regulators will be approved for this page.
Thanks for the great and educational content – greatly appreciated. I hope you can help me with the following problem:
My air filter regulator has a max rating of 150 psi. My 35 gallon tank is set for 140 psi cut out. For the past year I had the regulator set for 90 psi but would now like to increase it to 100 or 105 psi but I can’t get my regulator above 90 psi. I can turn it down to 60 psi but when I raise the pressure it won’t go past 85-90 psi. keep turning the knob 6-8 turns does not change anything. When turning it back down it takes 6-8 turns before the pressure starts to drops. It makes no difference if my tank reads 120 or 140 psi. Checked the diaphragm but all looks good. No leaks. It’s 2 years old. Any suggestions ??
Thanks in advance.
Thomas
I have a small twin tank unit that has a broken regulator. I took it off and use it without the regulator. It shuts off at 110 psi and starts up at 85 psi . The regulator would not allow more then 90 – 100 psi .
It it SAFE to use it with out the regulator?
there is an arrow on the bottom of my regulator( Porter Cable), should this face into the tanks or towards the air hose outlet?
I’ve recently bought an air compressor (Dewalt) and the manifold assembly was leaking air badly. So I shopped around and couldn’t find the manifold I needed. So I bought one from ridgid which fits my lines and has the same set up as my Dewalt one (same amount of connectors and regulator) but the tank valve goes up to 250 and the compressor says it’s good for maximum of 200 psi. Can I still use the valve and regular assembly. Or with it being a 250 psi valve will it not stop filling up and damage my compressor?
I have a 21 CFM 80 gallon compressor. The regulator has to be readjusted to maintain set pressure even when using very small amount of air.
If I put a blow valve with an 1/8 in hole in nozzle on the hose and open it up the pressure gauge on regulator will drop from 140 psi to 100 psi and then maintain pressure at 100.
The tank outlet is 1/2 into a 1/2 ball valve shutoff into 4 inch long 1/2 inch pipe to 3/4 in inlet on regulator then out through water separator then hose.
While blowing air I can readjust regulator to a higher pressure and it will maintain that pressure however when I stop blowing the regulator gauge goes up to tank pressure. If I open the regulator to full open I only get a 1 or 2 psi drop when opening the blow valve. It seems as though the regulator really isn’t regulating very well. It is a new regulator that cost about $55 so not a supper cheapy but certainly not the best. I bought the 3/4 in regulator to make sure it could flow lots of cfm and would not be a restriction. Do you think the regulator is defective.
Thanks
I have an older sanborn powermate with the square dial type regulator. It leaks when the tank pressure is above the line pressure. If I dial the regulator to tank pressure or above it doesn’t leak. When I dial below it blows off the air to equalize but continues to hiss slightly. When dialed up a notch it quits but within seconds it equalizes the line pressure and leaks. It will slowly leak until the tank pressure is 0 if the regulator is all the way down. Any ideas?
Sir – My Craftsman air compressor regulator knob suddenly would not turn. I replaced the regulator and it still does not turn. I can’t figure out why or what to do. Please help!
Respectfully,
Hi, WillyR!
Tons of great info here…thank you so much for it!
I have a small Bostich air compressor and with your help here I diagnosed it as a bad regulator. I ordered a replacement and after about 6 weeks it finally arrived. I hope I don’t have to go through that again…..
Anyway, my one question is this….. I did notice when taking the pressure gauges off the defective regulator, Bostich had used some sort of sealant on the threads which I removed with a brass wire brush. Not having any sealant, I used about 3 wraps of Teflon tape on each connection. So far, the tank holds air for about 2 hours before recycling (when the regulator was bad, it would recycle 4-5 times just topping of my wife’s tires 🙂
Do I need to remove the Teflon tape and place some sealant on all the threads or should I just keep on keeping on?
TIA, WIllyR!
Hi, great article! I have a porter cable cmb15 that the main tank goes to 150 psi. The problem is that it will only go to 150 if I have the regulator set to max. Otherwise it follows the regulator. If I set the regulator to 100 then the main goes to 100 and it keeps running while it bleeds off the air somewhere. Is it the regulator that is the problem?
My regulator seems to work ok, but the pressure gauge does not drop when dialing down air pressure. I installed a new gauge but have the same problem. It reads tank pressure but but doesn’t drop when output pressure is dropped.
I have a Bostitch CWC 200ST that has the same regulator pictured by Andy back in July.
The knob on mine is stripped out and needs to be replaced. But can’t figure out how to disassemble the regulator to take the knob off so I can insert it into the panel. It has a hex piece of metal on the end of the knob screw that prevents the knob from coming all the way off. Hoping there’s a way that doesn’t involve destroying that retaining nut. Thanks in advance.
I have a new Husky oil free 8-gallon air compressor I purchased this year. I either have a [ outlet / downstream ] regulator malfunction, or I need to be educated on the normal operation of the regulator gage on the compressor. The compressor has 2 gages: one shows me the tank pressure and it is preset by manufacturer to shut the compressor off at 150psi, which it does properly. ( And when tank pressure drops to its preset low point, the compressor kicks back on and builds pressure back up to 150psi.)
My issue and question is concerning the outlet / downstream tool pressure regulator valve/gage. I have a stapler that recommends a minimum of 60psi and the max is 90psi. So I adjusted the regulator knob clockwise or counterclockwise to where the output regulator pressure reads 75psi. My confusion is: when i use the stapler tool, the tank pressure starts to drop from 150psi as expected, but the output regulator pressure also starts to drop well below the tools recommended minimum pressure of 60psi. The tank pressure is still above 110psi, which confuses me. Is the output pressure not supposed to hold at my 75psi setting? Or is it supposed to drop down with tank pressure? ( I thought that as long as the tank pressure was above 75psi, then the output regulator pressure setting should remain at 75psi. ) Please educate me on what is happening. Thank you.
I have AS18-2 air compressor. When I try to turn the valve for adjusting the air, it turns slowly in both ways and it feels like it’s been tight and the pressure is always on same level. Can please tell me if there is any way to fix this issue or do I have to buy new pressure valve? Thx
I installed a regulator on a 2-gallon portable air tank. Can I also use the regulator to fill the tank or will air flow opposite the direction intended damage the regulator?
I put a new regulator/moisture trap on my compressor. It builds pressure in the tank fine as long as the regulator is at 0. As soon as I go to adjust it to correct psi, it dumps all the air out of tank. Nothing reading on tank or regulator valve and won’t build pressure again until regulator is back to 0……help
I have a 21 gal Central Pneumatic compressor from HF that was given to me by a friend. It will successfully fill to 125 PSI and cut off.
I had a ball valve between the regulator and the quick connect for the hose. When I would connect the hose with just a simple air gun attached and open the ball valve the pressure on the regulator would drop from 90 PSI to zero.
The motor would cut back on and the regulator would fill back up.
Often, the safety valve would trigger with the tank around 120 psi.
When the regulator was back up to 90 PSI, I would try to use the tool and it would blow air for a couple of seconds and the regulator pressure drops back to zero. Motor cuts back in to refill.
I’ve replaced the regulator and remove the ball valve. Replaced the quick connect with a new one. All are 1/4″ NPT fittings.
I’ve ordered a new safety valve thinking that something may be up with it but I doubt it. Any ideas? I can replace the pressure switch and maybe the check valve. But, by that time, I probably should have just bought a new compressor.
I just purchased a cheap Craftsman 2.6 scfm with a 6 gallon pancake tank (CMEC6150
). My intent is to use this to fill tires, and some small tools. However, in the event I need to use my Ingersoll Rand professional impact wrench to take off a lug nut, I’m expecting to get 3 maybe 4 sec’s on 90 PSI air. Would I likely need to replace the factory air regulator on this small air compressor to get a sufficient flow because of the small rating of the compressor? Great thread and thank you.
I have a hitachi 6 gallon EC510 compressor. Everything runs fine, including the regulator as far as adjusting the pressure to what I need. The problem Im getting is after shooting a few nails. Whether 1 1/4 roofers or 12d framing nails at 100 lbs or so, after the first 2 or 3 nails (shot within 2-5 seconds of eachother) the following nails set less and less until I wait 5-10 seconds to shoot again. Seemingly from the regulator not recovering nearly as quickly as it used to or as I need it to. The discharge of air seems sluggish. What could be causing this? The regulator on this compressor from what I’ve gathered is part of a manifold which costs $111 dollars and ships within weeks from the one supplier I quickly checked. That may not be in my best interest to replace, for obvious reasons and especially since Im not sure what the problem may be exactly. Any help or suggestions are greatly appreciated!
I have a regulator that is making a trumpet like sound when air passes through it. What could cause this?
Hi All,
please I’m so confuised I have big problem with the quincy Compressor air.
the regulation are fail what can I do to reasolv this problem?
normaly it’s will be regulate between 5 to 10 barg to load and upload
I have a quick question that I’m hoping can be answered before tomorrow morning for school. My question is if a gauge is manufactured to have the ability to read out from 0 to 100psi, why would someone want to re-range it to read only 10 to 70psi?
Hello, can you explain to me the difference in ratings of compressed air regulators? I have a very inexpensive regulator filter combo that I want to put on my 60 gallon 175psi max air compressor. The regulator is rated for 80scfm @ 100psi and says that the max pressure is 145psi. My question is, does the 145psi max mean that the regulator is only meant to regulate pressure as high as 145psi and anything above will not be accurately regulated, or if I connect this regulator to 175psi I am going to break my regulator?
Hi folks – what happens if I install the regulator in the wrong direction? I recently took apart my regulator to reseal the component threads and realised that the regulator does not have an airflow direction marking. Can anyone tell from these photos which way I should reassemble it? Any help would be much appreciated!
Where can I find a regulator #243for a lIl red air compressor model BAR233P?
Hi. I just got a new Husky air compressor. I am having trouble setting my regulator valve. I set it to a maximum of 90 psi, but my compressor keeps pumping up until I switch it off. Am I doing something wrong? Thanks in advance for any help. Jack
I have an iwata compressor and the knob will not turn to allow air flow. The knob is in the up position, just will not turn. I have used it for about four years and the compressor was working fine a few days ago. The tank can still be drained from the water trap filter bleed. Can the regulator be replaced with a third party regulator. It’s the Iwata IS-900 model and replacement parts are over $100 while many third party regulators are under $20.
Hello- I retrofitted a portable air tank and accidentally hooked up the air pressure regulator (0-15 PSI) backwards with the air flow arrow pointing toward the tank. and realized this when I filled the tank to roughly 50-65PSI and the air regulator gauge did not work properly. I switched the regulator around and it appears the gauge is still not working properly. It never drops to zero when the valve is completely closed and only starts increasing at around 8 PSI where the needle is stuck. It is an oil filled gauge and it dropped a little when tapping it but clearly it is not working properly. My question is would having hooked up the regulator backwards caused damage to the gauge or is it likely I received a bad gauge?
i purchased a new dewalt 165psi , 6 gallon pancake compressor DWFP55126. the tank gauge works fine,it turns on and off at the correct cut in/off points. my issue is with the regulator, when i set it to 90psi and use a nailer or just the blow gun, the pressure more than not does not return to 90psi after i discharge some air. sometimes it goes as low as 75-80 psi and as high as 100psi,basically the pressure it returns to or at least what the gauge says is totally random it seems, any ideas? likely just a bad regulator or am i expecting to much for the regulator to return to 90 psi exactly? or within a few psi atleast
I have a Campbell Hausfeld WL802600AJ, 155PSI, 29 gal tank. The Regulator and both gauges and outlet valve receivers are ll one unit. When I turn my regulator knob counter clock wise (lower), the pressure releases from both the tool outlet and the tank gauges. I cannot remove the regulator and turn it around to face the outlet valves, it does not come apart. Do I need to buy an entire new unit?
Additionally, the regulator comes attached to a manifold. It is part # WL024502AV or WL022500AV. I will try to add a PIC. All regulator knob settings, adjusts both gauges to the same pressure level. It sets the Tool valve pressure quickly, then continues to bleed air from the tank, the air comes from under the regulator knob.
/ Ray
Hi,
I am pretty new to the world of air compressors and I am trying to better understand how I can utilize air regulators. Here is my question. I have a very large towable air compressor that produces around 185CFM at 100 psi. I have a dessicant air dryer that has a three stage filter that is connected inline between the tool and the compressor. This dryer is rated at 142PSI and about 40CFM airflow. My tool requires at least 30 cfm at 100psi. My questions is whether or not an air regulator installed between the air compressor and the dessicant air dryer would allow me to safely use the air dryer with this large air compressor. Do air regulators allow you to use tools and filters that are rated way lower than the compressor in terms of PSI and CFM? I hope I am making sense. I have heard of tools and filters exploding from too much pressure. Thank you
Hello All,
I have an Ingersoll and Rand water trap regulator. It has been working well for 8 months until today. The regulator still does it job at lower psi’s, but once I try to spray at higher pressures, it shoots straight to 150psi and stays there. I don’t want to buy a new one as they run around $100, any ideas about how dire this problem is and what I could do to fix it?
I bought a used DeVilbiss Pro Air 2, model # 430-1 , max pressure 125. When I turned it on the first time, it built up pressure to about 125 and air started coming out of the small relief hole below the pressure line on the regulator.
I was able to find a new regulator and installed it. Same thing. It built up pressure until about 125 and air started coming out of the small relief hole at the base of the metal pressure line attached to the regulator. It will continue to bleed off until the tank is empty unless it is turned on again. It holds the pressure will running but not while not running.
Any ideas what is happening? Thanks, Kurt
hi everyone my question is i set my compressor outlet @2.5bar but when it compress down to 2 bar when it use from tank it rise to the previous so how can i fix it
I have an air compressor that I just purchased. When I decrease the air pressure the regulator leaks until the pressure of the entire tank matches the setting on the regulator. Any idea what is wrong?
Hi,
I have an Iwata Smart Jet Pro that has developed a problem. I was unable suddenly to turn the pressure regulator knob. At the same time the pressure gauge stopped working, not budging from zero despite the compressor blasting air to my airbrush. I assumed that the problem stemmed from the pressure knob. I took advice and removed the knob cap and loosened off the nut. I can now move the knob again, however the dial still does not adjust the pressure and the gauge still does not move. My airbrush blasts air, but I have no control over the amount. Any advice on how to solve this will be gratefully received,
My air regulator knob is very hard to turn. Is there a lubricant that should be used? It’s not leaking.
Hi Willyr,
first off, thank you for this site and the wealth of information shared! i’m a compressor newb and learning along the way. Anyway, my question is with regards to my old sears/craftsman compressor (model 919.717521 2hp) from 1980 (bought from the original owner and it’s in beautiful shape!). I think there’s a leak somewhere in the regulator. I’ve tried googling for parts kits and ended up talking to a bunch of compressor repair guys who keep referring me to someone else!
anyway, can i still rebuild this regulator or should i just try and get an aftermarket one to try and fit in? will there be any issues with that? with the compressor off, there are no leaks, it only hisses/leaks when i spin the regulator on and it sounds like it’s coming from around the regulator itself. i’ve heard cracked diaphragm from the same guys above. just wanting to confirm this diagnosis first and your thoughts on the fix.
‘preciate any tips/advice! (hope pics work)
cheers
romey
Hi, I just installed a Kobalt 3/8 in regulator on my twin tank Central Pneumatic wheelbarrow compressor. I bought it used and when I ran it it would pop off at 150 tank pressure. This regulator continuously bleeds off pressure and won’t let me get any higher than 60 psi and tank pressure can’t build any higher than 70; did I just install a broken piece of junk?
I have a mini air compressor are the air tank pressure and the air regulator suppose to read the same . My tank reads over 200 in the red the regulator shuts off at around 100
Howdy, I have an old Emglo MK5HGA-8P compressor and the regulator screw broke. It is an old enough unit that I can’t find parts anywhere for it. The regulator screws into a manifold and comes apart easily, do you know of anywhere to get parts or do you know of a screw in replacement that will go in the manifold?
Aloha. I have an old military compressor, probably 80 gallons or so. It’s set to shut off at 147psi and turn back on at about 117psi. The tank has its own gauge, the regulator has a gauge and I put one after the regulator before the tool’s hose. I drained all the air out of the compressor and the hose end, unscrewed the pressure set knob all the way to the stop and filled the compressor tank. All three gauges read 147psi. Shouldn’t the out pressure be much lower than the tank with the pressure set knob backed off all the way? I’m thinking I bought a faulty regulator. I’m not hearing any air leak from the regulator.
Thanks,
Chris
(UPDATE: Disregard the question. I took it apart and found that the adjustment screw was stripped.)
Chris, we’ve included both your question and upates as your findings will, we are sure, help others with a similar regulator problem.
So I’m not much a DIY’er, but a couple Christmases ago my father-in-law bought me a Porter Cable 150 psi air compressor. Embarrassingly I just tried to use it for the first time today to air up a low tire on my car. I followed the instructions about attaching the tube and proper fitting, turned the regulator pressure knob fully counter-clockwise and turned it on. When the tank air pressure reached about 140 psi it shut off and I turned the regulator knob clockwise and was going to set the regulator pressure to about 100 psi. As I turned the regulator knob the tank pressure decreased and the motor started running again, before the pressure in the regulator reached even 20 psi. That’s not normal, is it? Any help is appreciated.
I have a ABAC Pole Position Compressor 2HP / 24Lt – It is just a cheap model and fairly old.
My question is regarding the Pressure gauge and regulator – this seams to be 1 unit on my item and only has 1 gauge which shows the pressure of the tank, The regulator only has numbers round a twist knob however it has come loose and so the numbers do not match the reality i.e. when on number 3 air is only just escaping.
Do you have any ideas how to fix this? Can I repair it, if so how will I know if the pressure is correct.
Another option will be to replace the regulator – any help identifying the right one would be helpful.
Thanks
I have a Craftsman air compressor model number 919.167280. It has pressure regulator D27253. The nut on the inside of the regulator has stripped out and now the regulator won’t keep pressure. Does anyone know of a place to get a replacement nut for the regulator. I know they are most likely disposable, but a new regulator is around $60 and I can’t bring myself to pay that when all I need is a $.05 nut. Any help would be appreciated. Thanks.