Hello Rich,
The SKU on my unit is indeed 95630.
However, if you look under the specifications for all three SKUs it lists, "Thread Size- -1/8 in-27 NPT with 1/4 in-NPT adapter."
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
Yes, I see that reference in the Specs. There is a similar reference in the Overview as well as on the compressor box which reads,
But, I honestly don't know what that means. With the included hose, you can directly attach the airbrush to the compressor. No 1/4" adapter is needed.
When I first read how you replaced the air outlet fitting on the compressor, I removed the air outlet fitting on my compressor. It is 1/8"x1/8" M/M.
Rich
Alton Junction
Hello All,
richhotrainI removed the air outlet fitting on my compressor. It is 1/8"x1/8" M/M.
OK, Great!
That is the 1/8 inch NPT/NPS to 1/8 inch-27 NPT M/M adapter fitting that allows the airbrush hose to attach to the output of the moisture trap.
As I keep saying, remove the fitting on the output side of the moisture trap.
Put it aside because you will need it later.
No matter the size of the output of the moisture trap; 1/8 or 1/4 inch, the threads should be NPT.
That's why the NTP to 27 NTP adapter fitting is used.
If the new air regulator is F/F 1/4 inch NPT on both the input and output sides, there is a reduction adapter that will go from 1/8 inch M NPT to 1/4 inch M NPT.
On the output side of the new regulator; 1/4 inch NPT, you will need a 1/4 inch M to 1/8 inch F NPT.
Then you can use the 1/8 inch NPT to 1/8 inch-27 NPT- -that you saved- -on the output of the newly installed regulator with the step-down 1/4 inch to 1/8 inch NPT adapter.
Your best option is to remove the current output fitting from the moisture trap, take the compressor and the new regulator to your local hardware/big box store, and "trial and error" the fittings you need.
In my experience with Ace Hardware stores, there is a section in the tool aisle that has air compressor-specific fittings.
The plumbing aisle has a more generic selection of fittings that offer a bigger selection, including step-up and step-down adapters.
You just need to find the correct fittings and adapters for your needs.
jjdamnit Is that the 1/8 inch NPT/NPS to 1/8 inch-27 NPT M/M fitting? As I keep saying, remove the fitting on the output side of the moisture trap.
Is that the 1/8 inch NPT/NPS to 1/8 inch-27 NPT M/M fitting?
It is a 1/8"-NPS Male x 1/8"-NPS Male fitting. The included air hose fits on this fitting. The included air hose will not fit on a 1/8"-NPT Male fitting.
richhotrain The owner's manual states that the air outlet on the compressor is 1/8"-27-NPT Male. It further states that the air inlet on the airbrush is 1/8"-27-NPS Male. That said, when I just went back to look at the compressor box, it states that the air outlet on the compressor is 1/8"-27-NPS Male. So, there is an inconsistency between the owner's manual and the label on the compressor box that I just noticed for the first time. My best guess is that the label on the box is correct. This would make sense since the air hose connects perfectly from the airbrush to the compressor. Therefore, the air hose fittings must both be 1/8"-27-NPS Female. Interestingly, I do have NPT fittings where the 1/8"-27 female end connects to the 1/8"-27-NPS males. However, I have tried without success to connect a 1/8"-27-NPT male to a 1/8"-27-NPS female. Rich
The owner's manual states that the air outlet on the compressor is 1/8"-27-NPT Male. It further states that the air inlet on the airbrush is 1/8"-27-NPS Male. That said, when I just went back to look at the compressor box, it states that the air outlet on the compressor is 1/8"-27-NPS Male. So, there is an inconsistency between the owner's manual and the label on the compressor box that I just noticed for the first time.
My best guess is that the label on the box is correct. This would make sense since the air hose connects perfectly from the airbrush to the compressor. Therefore, the air hose fittings must both be 1/8"-27-NPS Female.
Interestingly, I do have NPT fittings where the 1/8"-27 female end connects to the 1/8"-27-NPS males. However, I have tried without success to connect a 1/8"-27-NPT male to a 1/8"-27-NPS female.
Yes!
Remove that fitting you have circled.
That's the adapter fitting you will need later, on the output side of the newly installed regulator to the airbrush hose.
The M/M fitting threads into where that fitting you circled was removed from on the moisture trap.
From there, it's a matter of matching the output of the regulator to the fitting you first removed.
As I posted earlier, using an "O" ring between the moisture trap and the new regulator was needed to completely seal my system.
jjdamnit From there, it's a matter of matching the output of the regulator to the fitting you first removed.
Have faith!
I tried my grand experiment this morning without success. I removed the 1/8"-27-NPS x 1/8"-27-NPS MxM fitting from the air outlet on the compressor and tried to replace it with a 1/8"-27-NPT x 1/8"-27-NPT MxM fitting. No dice. That did not surprise me. Although both NPT and NPS have the same thread angle, shape, and pitch (threads per inch), NPT threads are tapered and NPS threads are straight (parallel).
I think the fact that the Central Pneumatic compressor has three different SKUs on the Harbor Freight website indicates that the manufacturer has taken liberties with the compressor design, at least as it relates to the fittings.
If I am going to find a way to install an air pressure regulator on this compressor, I need a different solution.
You keep using the wrong fitting between the Female output of the moisture trap to the Female input of the pressure regulator you are trying to install.
richhotrainI removed the 1/8"-27-NPS x 1/8"-27-NPS MxM fitting from the air outlet on the compressor and tried to replace it with a 1/8"-27-NPT x 1/8"-27-NPT MxM fitting. No dice. That did not surprise me. Although both NPT and NPS have the same thread angle, shape, and pitch (threads per inch), NPT threads are tapered and NPS threads are straight (parallel).
The fitting you circled in your photo is not a 1/8"-27- x 1/8"-27 (dash twenty-seven designation)-NPS fitting as you keep erroneously presuming!
It is a 1/8 in-27 (dash twenty-seven designation) NPT on one end with either 1/8 in-NPT or 1/4 in- "standard" NPT on the other side, no "-27" (dash twenty-seven designation) on that end.
That's why it is an adapter from "-27" (dash twenty-seven designation) threads to "standard" NPT threads!
One side of the M/M fitting is 1/8-"27" (dash twenty-seven designation) NPT to fit the airbrush hose.
The other side of the same fitting is a "standard" 1/8 inch NPT! (Or "standard" 1/4 inch NPT as on my unit.)
Note there is no "-27" (dash twenty-seven) thread designation on the opposite end of the fitting.
Trying to use a M/M fitting with the "-27" (dash twenty-seven designation) on both ends won't fit the Female port on the moisture trap or the regulator whether it's an NPT or NPS.
You need a M/M fitting with the "standard" NPT designation on both ends. Not a "-27" (dash twenty-seven designation) on either end!
PLEASE READ THIS VERY CAREFULLY:
Any fitting you use with a "-27" (dash twenty-seven designation) WILL NEVER work between the output of the moisture trap and the regulator you are trying to install inline- -no matter the size; 1/8 inch or 1/4 inch, or pitch- -NPT (tapered) or NPS (straight).
The "-27" (dash twenty-seven designation) is for the airbrush hose fitting. That's why it's a 1/8 in-27 (dash twenty-seven designation) NPT M to a 1/4 in NPT M ADAPTER!
The fitting you need between the moisture trap and the regulator, whether 1/8-inch or 1/4-inch CANNOT have a "-27" (dash twenty-seven designation)- -whether an NPT or NPS fitting!
Perhaps explaining to him why a "dash-twenty-seven designation" means something other than nominal threads per inch might actually accomplish something meaningful from all that verbiage.
⅛ in. 'standard' NPT is 27 tpi... by standard. (Think 'T' as 'taper' rather than straight.) He indicated that he recognized this before you found a need to post.
Overmod⅛ in. 'standard' NPT is 27 tpi... by standard. (Think 'T' as 'taper' rather than straight.) He indicated that he recognized this before you found a need to post.
Several replies ago I had mentioned that many, but not all, airbrush compressors and accessories use both 1/4 and 1/8 British Standard Pipe Parallel (BSPP) fittings. These are straight thread and require an O ring to seal any pressure. Apparently my reply fell on deaf ears.
If your regulator has 1/8 NPT and your moisture trap has BSPP you'll need an adapter like this.
https://www.augustindustries.com/product/bspp-adaptor-r-1-8-to-npt-1-8/
If you want to go from 1/8 BSPP to 1/4 NPT look here:
https://www.paascheairbrush.com/HF-116
BSPP is 28 threads per inch and 1/8 NPT is 27. No go.
M5 x 0.5 BSPP is quite small as this is usually the thread on the airbrush itself. 1/4 BSPP is probably more common at the compressor.
Good Luck, Ed
Let me begin this reply with a few somewhat relevant comments.
First, my apologies to Dunderhead, the OP, for hijacking his thread. When I first replied to this thread, I never expected the extensive exchange of posts trying to solve my problem. I am grateful to jjdamnit for all of his time and patience.
Second, I have used the W.W. Grainger local branch near my home to order and pick up various fittings in an attempt to find the correct parts to add an air pressure regulator to my airbrush/compressor kit. Grainger has an outstanding website that provides critical detail on the sizes and dimensions of fittings.
When I first tried to install the air pressure regulator, I realized that it required 1/4" fittings versus the airbrush and compressor with their 1/8" fittings. What I didn't realize was that various fittings differentiated between NPT (tapered threads) and NPS (straight threads). That took multiple trips back and forth to Grainger to obtain the correct fittings.
The Grainger website provides not only specific information on fitting types and sizes, but each fitting also provides a "dimensional drawing". From what I can determine, all 1/8"-NPT fittings and 1/8"-NPS fittings have 27 TPI (threads per inch). Supposedly, NPT and NPS fittings are not interchangeable. However, as I mentioned in an earlier post to this thread, I am able to connect 1/8"-NPT female fittings to the 1/8"-NPS male compressor fittting. That said, I am unable to connect a 1/8"-NPT male into the 1/8"-NPS opening on the compressor with its original fitting removed.
I mentioned in an earlier reply that there are inconsistencies among the Harbor Freight website, the Central Pneumatic owner's manual, and the packaging regarding the size of the fittings. I mention this again here because I am now considering the purchase of a Central Pneumatic air hose which may solve my problem since that air hose has a 1/4"-NPT female fitting on one end and a 1/8"-NPS female fitting on the other end. That said, however, the website indicates that the 1/8" fitting on the air hose is 1/8"-28-NPS. To my knowledge, there is no such thing as a 28 TPI NPS fitting. I believe that all 1/8"-NPS fittings are 27 TPI. Could Harbor Freight be wrong again in this instance?
One last thing. I removed that fitting once again from the air outlet side of the moisture trap that comes off of the compressor. Both sides of the fitting are 1/8", absolutely no doubt about it. Using an Optivisor, I can see that the threads are straight, not tapered, on both sides. NPS or otherwise, neither side is NPT.
I believe that Henry (Big Daddy) said it best.
BigDaddy As for hose to compressor fittings, it is a confusopoly like buying a new cell phone or life or health insurance. It is intentionally too complicated to understand.
As for hose to compressor fittings, it is a confusopoly like buying a new cell phone or life or health insurance. It is intentionally too complicated to understand.
Edit Note: I submitted this reply at nearly the same time as Ed's reply. Ed's reply does shed some light on the entire issue of NPS fittings and 27 TPI vs. 28 TPI.
gmpullman Several replies ago I had mentioned that many, but not all, airbrush compressors and accessories use both 1/4 and 1/8 British Standard Pipe Parallel (BSPP) fittings. These are straight thread and require an O ring to seal any pressure. Apparently my reply fell on deaf ears.
gmpullmanIf your regulator has 1/8 NPT and your moisture trap has BSPP you'll need an adapter like this. https://www.augustindustries.com/product/bspp-adaptor-r-1-8-to-npt-1-8/ If you want to go from 1/8 BSPP to 1/4 NPT look here: https://www.paascheairbrush.com/HF-116 BSPP is 28 threads per inch and 1/8 NPT is 27. No go. M5 x 0.5 BSPP is quite small as this is usually the thread on the airbrush itself. 1/4 BSPP is probably more common at the compressor. Good Luck, Ed
By the way, the air pressure regulator has a 1/4"-18-NPT female input and output port, requiring 1/4"-18-NPT male fittings for starters.
richhotrainBy the way, the air pressure regulator has a 1/4"-18-NPT female input and output port, requiring 1/4"-18-NPT male fittings for starters.
YES!!!
So why have you been trying to make a "-27" (dash twenty-seven distinction) threaded fitting work with an "-18" (dash eighteen distinction) "standard" fitting- -whether 1/8 inch or 1/4 inch or NPT or NPS?
jjdamnit richhotrain By the way, the air pressure regulator has a 1/4"-18-NPT female input and output port, requiring 1/4"-18-NPT male fittings for starters. YES!!! So why have you been trying to make a "-27" (dash twenty-seven distinction) threaded fitting work with an "-18" (dash eighteen distinction) "standard" fitting- -whether 1/8 inch or 1/4 inch or NPT or NPS?
richhotrain By the way, the air pressure regulator has a 1/4"-18-NPT female input and output port, requiring 1/4"-18-NPT male fittings for starters.
For the connection between the compressor and the regulator, I have a fitting that works. It is a 1/4"-18-NPT male x 1/8"-27-NPT female that fits from the input side of the regulator onto the air outlet of the compressor.
The problem is on the connection between the airbrush and the regulator. The air hose included with the compresssor has a 1/8" female fitting that connects to the airbrush, but I cannot find a way to connect the other end of the hose, a 1/8" female fitting to the output side of the regulator. I can find fittings where the 1/4"-NPT male fits into the regulator, but I cannot connect the other end of the fitting to the hose.
That's why I was so intrigued by your solution of moving that compressor fitting to the other side of the regulator. Unfortunately, my compressor fitting is different than yours and it won't work.
Just a brief update on my issue with the air pressure regulator. I never did manage to find fittings for it so I moved forward without it. Turns out, I don't really need an air pressure regulator with this compressor. The compressor is small and only puts out a maxium 56 psi. With the airbrush attached and loaded, the pressure drops to around 18 to 20 psi. This setup does a beautiful job, no paint blobs, no spitting, just a nice coat of paint.