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Discussion Starter #1 (Edited)
Hi all. It has been a while since I posted. Many years ago I bought a Master Airbrush compressor an an Iwata Revolution airbrush. Both have been used and even occasionally abused for years and have never failed. I love them both. A link to the compressor is below.

The spring inside the pressure regulator finally corroded and I ordered a new regulator/trap/gauge assembly. It looks identical in every way, only with the Paasche brand. It came with a large output fitting that I managed to unscrew despite the nasty pipe thread compound they used. Why they can't just use teflon tape like the roll that came in the box is beyond me. It came with no input fitting to connect it to the compressor.

My plan was to remove the old "in" and "out" fittings and reuse them. No go. They are not coming out of the old regulator/trap/gauge assembly. Whatever pipe glue they used isn't ever going to let go. So I need new fittings, and I have no idea what size they are or where to get them. One would be the male-male fitting that goes from the compressor into the regulator/trap/gauge assembly. The other is the male-male fitting that comes out of the regulator/trap/gauge and goes into the airbrush hose.

Naturally things go wrong exactly when we want to do a project, right? I temporarily moved the new spring/plunger/filter assembly from the new one and put it inside the old one. It seems to work fine. As far as I can tell they are identical. I cleaned out the corrosion from the old spring as best I could, but it made a real mess inside.

This temporary fix will work for a few days, but I'd like to do the job right and get the proper fittings to install the new one. What sizes do I need and where do I get them? I also need to know what types of pipe threads they are.

If this is something I can get at Home Depot or Lowes, that would be nice. I can order them online if needed.

The compressor and hose:


Thanks!

Never Get Old
I mean it - just don't!
 

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Discussion Starter #2
I'm thinking the output side may be this:


$8? Really? The price is ridiculous.

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I'm thinking the output side may be this:


$8? Really? The price is ridiculous.

Never Get Old
I mean it - just don't!
But you get free shipping and can have it tomorrow. :)
I looked around and that price is about the same everywhere, but some sites you had to pay for shipping and wait a few days.
For $4 bucks more you can get this kit by tomorrow.

You can go to HD and ask the one in control of that department if he has one, if they do I would bet they are about the same price.
Bring a picture of the one in Amazon with the specs with you.
 

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Discussion Starter #4
If that's the right one, I can get them for $1-2 on ebay. The problem is that I don't know unless I have it in my hands and by then it's too late. That's the whole problem with what we once called "mail order" shopping. Surely someone knows the correct sizes and thread types.
 

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If that's the right one, I can get them for $1-2 on ebay. The problem is that I don't know unless I have it in my hands and by then it's too late. That's the whole problem with what we once called "mail order" shopping. Surely someone knows the correct sizes and thread types.
Let the thread sit, someone may know for sure.
I am with you about having it in my hands. I would say that is what you need but I am not 100% sure.
The only way I see them on e bay at that price is if you buy more then one?

Did you try using a little heat while trying to get the old one off?
 

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Discussion Starter #6
Heat would have been my next step if the spring, plunger, and filter from the new one hadn't fit perfectly into the old one as a temporary fix. I stopped short of force for a temporary solution.

It's pretty ridiculous when the whole pressure regulator assembly only costs $15 and then they want $8 each for two fittings. Hobby stuff often gets marked up this way. Always try to find a non-hobby source for things when possible.
 

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Discussion Starter #8 (Edited)
$1-4 on ebay so not "stuck" with their parts. Just need to know the correct sizes and threads, and in fact it's identical in every way to the one I bought from Paasche as posted above. So, not stuck with either brand. Threads and sizes are not proprietary to these companies. Hobbyists just get fooled into thinking they are too often, or they just get confused, or can't find accurate info, like me.
 

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Generally, stuff meant for hobby use is of smaller scale and force than the things we use for household repairs, so you're not real likely to find the correct item at a big box store. Threads are not generally going to be an issue, these things are standardized. They also are also almost always 1/4" or 1/8", and you should be able to tell which by eye.
 

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Discussion Starter #10
This is how they get a premium price when there is confusion or lack of info:

BSP
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BSP thread form stands for British Standard Pipe and is common in Australia and the commonwealth countries. It is based on trade size rather than actual diameter which can lead to some confusion when measuring ports.

There are two types of BSP threads;

  • Parallel (BSPP) - also known as G or Rp
  • Tapered (BSPT) - also know as R or Rc
NPT
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NPT stands for National Pipe Thread and is an American standard thread. It may also be reffered to as MPT , MNPT or NPT (M) for male external threads and FPT, FNPT or NPT(F) for female interal threads. A thread sealant must always be used to achieve a leak free seal (except for NPTF). It is also based on Trade Size rather than actual diameter (similar to BSP in this regard).

Both threads have the same pitch, angle (60 degrees) and shape (flat peaks and valleys).

BSP vs NPT
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NPT threads are common in the United States and a few other countries, BSP threads are widely used in many other countries.

BSPT -British Standard Pipe Taper
BSPP -British Standard Pipe Parallel
NPT -National Pipe Taper
NPS -National Pipe Straight

While the actual specified outside diameters of American National Pipe differ slightly from those of British Standard Pipe, either thread may reliably be cut onto a pipe of its respective trade size. BSPT equivalent is NPT and BSPP’s equivalent is NPS.

Never swap threads if it is a high pressure application.

NPT/NPS and BSP threads are not compatible due to the differences in their thread forms, and not just the fact that most sizes have a different pitch. NPT/NPS threads have a 60° angle and have flattened peaks and valleys (Sellers thread form) where as BSP threads have a 55° angle and have rounded peaks and valleys (Whitworth thread form).

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I think we have it limited down to BSP. That probably rules out Lowes and Home Depot. If this really annoys me enough, I'll take it to a local gas pipe fitter just to find out. It would take them a whopping 30 seconds to figure it out. Heat will get the old ones out if I am determined to go that route. I'd rather get accurate info so that others in the future don't face this problem. It probably happens all the time. I can't be the only one.

Never Get Old
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If you have a Paasche regulator, they call for 1/4 npt fittings. :) Should be at any good hardware store.
 
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