Tube Res with 1/2 inch fittings ?

Does anyone know where I can locate one of these or of this design type with 1/2 inch fittings ? Everything is either 1/4 or 3/8's. Thanks in advance for any suggestions

I've never used one of those before but, couldn't you just replace the barbs with feren't OD barbs? Something about NPSB thread (not sure if that's the right acronym)

Just get some 1/4'' NPT (I believe) threaded barbs for 1/2'' ID tubing and change them out.
McMaster-Carr has every fitting imaginable.

Im confused.If its 1/4 inch, then throwing a 1/2 ID inch fitting on it doesnt help as the 1/4 causes restricted flow, Correct?

Maviryk said:

I've never used one of those before but, couldn't you just replace the barbs with feren't OD barbs? Something about NPSB thread (not sure if that's the right acronym)

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There's NPT, which is a tapered thread, and BSPT, which is a straight thread.

glasslicker said:

Im confused.If its 1/4 inch, then throwing a 1/2 ID inch fitting on it doesnt help as the 1/4 causes restricted flow, Correct?

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Incorrect, because you're assuming they're both measured in the same way. Barbed FITTINGS are NOT measured by the ID of the barbed fitting, they're mesured based on the ID of the tubing that will fit onto them.
A barb with 1/4" NPT fitting and 1/2" ID Barb will have an inner bore of 3/8" through it's whole length.
Remember that the 1/2" barb will have 1/2" ID tubing clamped onto it so the Barb itself will have an ID of 3/8".
The NPT fitting on the other hand works the other way around. Generally you can add 1/8" to the NPT size to get an estimate of it's ID. If you search around on Mcmaster for fittings they have tables showing what each standard and it's measurements are in handy tables.

Just as an example, if you measured the tapping bit that makes a 1/2" NPT threaded hole you'll see that it's 5/8-inch in diameter.

Edit: Stupid acronyms...

npt threads

Captain Slug said:

There's NPT, which is a tapered thread, and BPST, which is a straight thread.


Incorrect, because you're assuming they're both measured in the same way. Barbed FITTINGS are NOT measured by the ID of the barbed fitting, they're mesured based on the ID of the tubing that will fit onto them.
A barb with 1/4" NPT fitting and 1/2" ID Barb will have an inner bore of 3/8" through it's whole length.
Remember that the 1/2" barb will have 1/2" ID tubing clamped onto it so the Barb itself will have an ID of 3/8".
The NPT fitting on the other hand works the other way around. Generally you can add 1/8" to the NPT size to get an estimate of it's ID. If you search around on Mcmaster for fittings they have tables showing what each standard and it's measurements are in handy tables.

Just as an example, if you measured the tapping bit that makes a 1/2" NPT threaded hole you'll see that it's 5/8-inch in diameter.

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I don't think so! I have barbs that are 1/2" NPT threaded and 1/2" ID all the way through. The ID of the barbs matches the ID of the 1/2" tubing I have attached to them. You are correct that you CAN buy barbs with OD's that match the ID of tubing...but why would you want to? And the OD of a 1/4" NPT threaded pipe is 0.532" - 0.540". So a plastic fitting with a 1/4" NPT (male) end and a 1/2" ID would have a wall thickness of 0.032" -0.040" and would bend or break off when you tried to attach a hose. Generally stores and the public don't pay much attention to the ID of barbs. I have found 1/2" NPT threaded barbs with 1/2" OD and with 3/8" OD in the same bins at stores! Carefull shopping (with a rule in your pocket) is a must. I was even able to locate 1/4" BSPT threaded barbs with 3/8" ID's for a European rad. Finding what you need is sometimes difficult and time consuming, but well worth the effort!

Anytime you go to a hardware store or what not and get a 1/2" barb it is talknig about the OD of the barb not the ID. Your 1/2'NPT 1/2"ID barb would have an OD of 5/8". For the res tho just get 1/4"NPT 1/2" barbs. as said before McMasters is a great place to look. Just click on Barbed Tube Fittings and it's part number 5463K465

Captain Slug said:

and BPST, which is a straight thread.

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Incorrect. BSPT is tapered just like NPT - The 'T' = tapered. BSPP is straight or parallel, the 'P' = parallel. Then there is UNF and NPSM. Now, if that res is made by innovatek, it likely uses G 1/4" thread which is BSPP 1/4" which has an inner diameter close to 1/2". This is the same size (1/4") thread that swiftech uses. Danger Den is moving all their thread to G 1/4" as well.

The actual Drill Bit Hole size for a 1/2" NPT tapped Threaded hole is 24/32" or 45/64" Which is critical to a good tap.... The type of thread is not all that important to a good seal so long as it is done right. It is the tube ID and sometimes the OD if you are using certain fittings that is important. You have to think out your whole loop and the TYPE of fittings you are using. Again the Tap Thread has nothing to do with rhe ID of the tubing you are using. Some will argue that certain BSPT and BSPP seal better ...... Bunk, BS whatever. It is all about standards used at the time of production and trying to meet the demands of european markets and such.
The OP should buy that puppy (provided it has no AL in it) drill out and tap the holes the way he wants it and be happy. However if he needs to buy the tools ..The right ones he is looking at 25.00 for a decent bit and 20.00 for an ok tap and a drill press with prob. a 1/2 chuck to do it right and of course the know how with all above.
overrall any proper tapped hole with the right thread will seal well. If I did'nt say it before IMO bigger is better.

Wow. OK.

SO I am trying to read sizes which are NOT the same. TO simplify, It's OD versus ID depending on what one is ordering.

If that's the case then I just need to attempt to speak with the MFG, explain that I want to retain as close to 1/2 inch id as possible throught my system, and find out if switching barbs is all that is required.

While I would love to drill and tap threads, I dont have the space for a nice shop yet. Had to sell my lovely home in Florida to open a company in Arizona.

Some day *sniff*, I'll have my big a$$ work shop back.

Thanks to everyone for sharing your knowledge.

From the tech specs:

Compatible fittings:
1/4" to 10/8mm compression
1/4" to 8/6mm compression
G1/4" Push Fit (10mm OD hose)
1/4" BSPP to 1/2" hose (brass)
1/4" BSPP to 3/8" hose (brass)

As I said, the THREAD is G 1/4" which is the SAME as BSPP. Danger Den has the fittings here: http://www.dangerdenstore.com/product.php?productid=210&cat=34&page=1

Which are the same that I used on my custom res seen here:

glasslicker said:

Wow. OK.

SO I am trying to read sizes which are NOT the same. TO simplify, It's OD versus ID depending on what one is ordering.

Click to expand...

You got it now! Just buy what you want after carefully assuring yourself that what is being sold IS what you want.