# Tubing type for concentrated NH03



## Alentia (Nov 26, 2011)

I am thinking of putting system together, where NHO3 is above and flow controlled by valve. I have bought almost all the equipment I need. The question remains with the tubing for NHO3. My glass aspirator bottle has 1/2" glass output and tubing needed for incoming into the vessel is 3/8".

I have looked and different Acid resistance charts and the only tubing, which withstands concentrated NHO3 is PFA/PTFE, which are really expensive and not readily available.

PVC tubing possibly can handle it, but not as great as PFA. My guess is to dilute NHO3 with 1/1 water, before use.

I have looked at hardware stores, some flex tubing like Watts advertise as Polyvinyl Chloride (PVC), however when you look at them it only marked as vinyl. 

Does anyone has any experience with tubing as well as PVC or PTFE reducers, as I need to drop my diameter from 1/2 to 3/8 on the way down?


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## 4metals (Nov 26, 2011)

Don't skimp on the tubing, nitric will oxidize most tubing PFA/PTFE is the way to go. Even more important when it's overhead. 

Check out US Plastics for fittings http://www.usplastic.com/catalog/default.aspx?catid=855&parentcatid=857


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## Alentia (Nov 27, 2011)

I have found some unexpensive FEP tubing here: http://www.fluorostore.com/cart

What about NOx output tubing, do I have to go expensive route as well? I have some Norprene A-80-F AXB00029 3/8" ID, it can not handle concentrated HNO3, but should be ok with NOx, should it?

Some PVC fittings here http://www.watergardengems.com/SUBc...bCategoryKey=341&subCategoryName=PVC Fittings


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## Geo (Nov 28, 2011)

Lowes has some clear pvc tubing that is lab rated.the label states " medical and laboratory safe ".

Watts 1' x 1-5/8" PVC Clear Vinyl Tubing Item #: 24959 Model #: RVSP Brittle point -40 degree ( -40 C) 
Pressure range 19 to 55 psi 
Multiple applications: beverage dispensing, drainage lines, aquarium lines, laboratory tubing

they will cut what ever length you need.of course in comes in different inside and outside diameters.


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