Non-Liquid 110 psi Nitrogen Pipes

""Consumer Reports wanted to find out if nitrogen is worth the price, so we purchased a Nitrogen Inflation System and checked out how well the inflation held up over a one year period. We evaluated pairs of 31 tire models of H- and V-speed rated, all-season tires used in our tread wear test from 2006. We filled one tire per model with air and the other with nitrogen. The test was quite simple: fill and set the inflation pressure at room temperature to 30 psi (pounds per square inch); set the tire outdoors for one year; and then recheck the inflation pressure at room temperature after a one year period.

The tires were filled and deflated three times with nitrogen to purge the air out of the tire cavity. We also used an oxygen analyzer to be sure we had 95-percent nitrogen purity in the tire--the claimed purity limit of our nitrogen system, which generates nitrogen gas from ambient air.

The test started on September 20, 2006 and the final measurements were taken on September 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. More important, all tires lost air pressure regardless of the inflation medium, so consumers should check their tires' air pressure routinely. No evaluation was done to assess the aging claim.""

Normal air is 78% N_2. Tire, or tyre, air is 95% N_2. My uneducated guess is that whatever works for shop air will work for N_2. I'd check with the local tyre shops.

Good luck.

Amazing reply

I don't know about Canadian regulations, but the same pipes used for air are good for nitrogen. You may want to paint the pipe green to indicate the fact that you have invested in nitrogen fill technology. Advantages of nitrogen over air have been discussed previously.

Canadian standards (based on USA standards) indicate pressures over 15 psi and volumes of approx. 10 gallons are subject to the pressure vessels act. All components in installation are then required to be "certified" in the province of use. Good luck.

The only requirement I am aware of is that the pipe must be labeled
with "There is one born every minute!" and its French equivalent alternating at one foot intervals.

Guest,

I have read the posts to date. As far as I know, the same standards that apply to compressed air piping would apply to compressed Nitrogen gas piping. I would agree with the desirability of painting the piping with a distinct marking to differentiate it from your normal compressed air lines.

--JMM

Many replies looks to be irrelivant to the simple question. The simple answer is- there is NO any special pipe requirement for nitrogen.

ufortunatly none of the replies as any idea of the pressure vessels act. Over 15 psi and approx. 10 gal. ALL pressure systems, piping, containers, etc. are subject to the Pressure Vessels Act. Yes I know not all systems are inspected but that does not change the law.

I think it is very dangerous for those of us not in Canada (or the relevant Province) to state with such certainty that there is no special requirement for nitrogen piping.

My background is oil and gas and we would on a refinery or similar use the same pipe class (material, flange rating etc) for Instrument Air and Nitrogen. Instrument Air is dried to the equivalent of -40°C and so has no corrosion risk as does nitrogen (depending on how you produce nitrogen).

However ordinary compressed air for driving machine tools is called Plant Air and is not dried and often has a higher corrosion allowance (resulting in thicker walled pipes) or is treated eg galvanised.

So assuming your shop air doesn't go through a drier then you could probably use lighter piping for nitrogen.

Utility services are often coloured or have coloured bands or the service painted on so that operators don't power their tools with instrument air (which could cause a plant shutdown by starving the control system of its motive power) which brings to another point.

I think it would be prudent to have a different coupling for tools to be used with nitrogen compared with those being used with air. Nitrogen will kill if you allow a restricted work space to become enriched in nitrogen. You cant smell or see it.

However all of the foregoing is I feel reasonable practice but may not be allowed by particular laws in Canada

"Nitrogen will kill if you allow a restricted work space to become enriched in nitrogen."

Blimey, nitrogen (and other gasses) can kill you if they dissolve in your blood at elevated pressure and the pressure is subsequently rapidly reduced. The boiling out of the gas causes what divers know as the bends. As far as killing at atmospheric pressure, nitrogen can be an asphyxiant. In this case, it is not the nitrogen killing you; it is the lack of oxygen. Either way you are dead, but the nitrogen didn't kill you.

In the spirit of good natured pedantry

In a nitrogen enriched atmosphere you do indeed die because of a lack of oxygen. However this begets the question...

Why is there a lack of oxygen?

Because there is a lot of nitrogen. Therefore the increased nitrogen causes the lack of oxygen that causes your death. Ergo the nitrogen is the root cause of your death and has killed you.

By exemplar if I take a fire arm, press the trigger etc and the bullet passes through vital organs causing your demise I cannot claim that the bullet killed you so the bullet should be on trial for murder.

OK I know this is not a good example as nitrogen is a passive killer but it does need to be kept in peoples minds that the consequence of misuse of nitrogen equipment is death.

The entire methodology of Hazard & Operability Studies (HAZOPs) which are a standard analysis tool in the oil/gas industry was developed when ICI had two fatalities due to entering a nitrogen purged vessel.