HP Oxygen Hose

[iain/hsm]

Instead, are the industry trying to prevent escape of stray currents of internally generated static electricity by installing a non conductive outer shield and thereby facilitate passage of electric currents through the conductive hose core ,and to the grounds (earth) at the hose ends? I think that is what you are saying or trying to say and it makes sense. After all, discharge through the shield could start a fire.

England and America. Two nations separated by a common language. George Bernard Shaw.

Agreed as above.

I don’t think we should be surprised that the hose manufactures do not want to get involved in certification of oxygen or approvals, in fact you will only see test results done on practically all other gases and everything else apart from oxygen, due to liability I assume.

 

[iain/hsm]

I looked up the SAE 100R7 specification at Gates and these hoses all have nylon tubes (cores) and none of them are specified for O2 service by Gates. I can't make a direct link work but just search SAE 100R7 here:
Gates Online Catalog

The use of nylon vs. teflon is a step backwards in oxygen compatibility. I don't know who is "certifying" these materials for O2 service but it definately isn't the hose manufacturer.

This is also not the same material as shown on the ANDI website. That stuff had a 5,000psi WP.

The approval of a hose suitable for a gas, a pressure and a service that is the job and responsibility of the pump manufacturer or supplier of the completed cleaned and tested hose assembly, not necessarily the tubing extruder or hose manufacture.

I quoted the SAE spec as it is the easiest, best recognized and an international standard for these thermoplastic hoses as requested, and most hose extruders/ suppliers will exceed these minimum standards for cyclic load, pressure and minimum burst, they are also available in small qtys and lengths.

For 5000 psig working pressure with a 4:1 ratio of working pressure to burst pressure then the SAE 100R8 spec would apply (not the R7).

I looked just now at the ANDI web site and they clearly state as follows:
(Quote from web page)

Code: 7-641AA-36
Price: $97.00
Quantity in Basket: none

This is the best quality thermo-plastic hose available. Multi-layered with a nylon core and rated for 5,000 psi / 345 Bar working pressure. Approved for Breathing Gas & Oxygen. These hoses have Stainless Steel swaged (crimped) ends to eliminate particulate contamination from surface corrosion. Available in custom lengths to 100 ft / 30 m. This part # is for 1/4 inch NPT male ends on both sides. 36 inch length costs $97.00, longer lengths are slightly higher. Choose your stock sizes here. (end quote)

 

[rjack321]

Teflon hose cores have a much higher oxygen index than nylon. Not than any of this matters that much, the valves and the nylon seat in them will go up long before any hose will.

 

[CraigAClark]

What working pressure are you looking for, 3000 or 5000? You can get an O2 cleaned hose, SS 316 with armour flex, any length you want in either 3000 or 5000 psi from PSI(Peter Skop Industries). They have female 1/4" NPT ends. I buy them all the time for systems that we make. They aren't cheap and you will need needle valves that have SC-11 cleaning to avoid adabiatic compression for safety.

If you are filling rebreather bottles off that particular booster, I would suggest the 5000 psi working pressure.

Craig

 

[rigdiver]

Thanks for the info.