Gas Explosions- Prevention

Tim McElwain

<a></a><ol><li><a href="http://r.smartbrief.com/resp/AseEdojnmkdmvDgkfDadccfCtZNM?format=standard">Odorant fade may have led to Mass. explosion</a>

DCP Midstream is not at fault for a gas explosion that killed one person and injured three others at a Massachusetts condominium project this past summer, fire investigators have determined. It is possible that the incident was a result of leaving the tank partially filled, causing odorant fade that made it difficult to detect leaks. Separately, a lawyer for the deceased's family said, "This was absolutely a preventable tragedy." <a href="http://r.smartbrief.com/resp/AseEdojnmkdmvDgkfDadccfCtZNM?format=standard">[u][color=#0000ff]ABC News/The Associated Press[/color][/u]</a><span style="color:#666666"> (12/29) </span><img src="http://cdn.smartbrief.com/images/briefs2/common/sm_share.gif" width="34" height="14" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet." /><img src="http://cdn.smartbrief.com/images/shim.gif" width="4" height="4" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet." /><a href="http://r.smartbrief.com/resp/AseEdojnmkdmvDjUfDadccfCTOvF"><img src="http://cdn.smartbrief.com/images/briefs2/common/linkedin.gif" width="14" height="14" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet.

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Ron George President of Ron George Design and Consul;ting Services in the December 2010 edition of Plumbing Engineer discusses recent proposed changes to the gas code. The article addresses the process of properly purging gas lines with inert gas. In addition the final purging to put gas into the piping system.



I strongly recommend anyone who works with gas piping try to get hold of a copy and read it. NFPA and ICC Internation Code Council working in conjunction proposed a TIA to existing National and International codes.A TIA is Tenative Interim Amendment.



Two very important aspects of placing gas lines into service: WHEN NEW FUEL GAS PIPING IS PUT INTO SERVICE, OR WHEN EXISTING PIPING IS RETURNED TO SERVICE AFTER A LONG INTERRUPTION, IT IS TYPICALLY NECESSARY TO PURGE LINES OF AIR.



Another point which I spoken often here concerning contractor safety and also customer safety is: COMBUSTIBLE GAS DETECTORS ARE GOING TO BE REQUIRED FOR ANY CONTRACTOR WORKING ON A FUEL GAS SYSTEM.



There are by the way detectors that can sample Natural Gas/LP and also Carbon Monoxide all in one detector.<ol><li><img src="http://cdn.smartbrief.com/images/shim.gif" width="2" height="2" alt="Right-click here to download pictures. To help protect your privacy, Outlook prevented automatic download of this picture from the Internet." /></li></ol>

Tim McElwain

Here are a couple of the proposed changes:

A.8.3.1.4 Combustible gas indicators are available with different scales. For purging, it is necessary to use the per­cent gas in air scale and to follow the manufacturer's oper­ating instructions. The % LEL scale should not be used, as it is not relevant to purging.

A.8.3.2.1 Where small piping systems contain air and are purged to either the indoors or outdoors with fuel gas, a rapid and uninterrupted flow of fuel gas must be intro­duced into one end of the piping system and vented out of the other end so as to prevent the development of a com­bustible fuel/air mixture. Purging these systems can be done either by using a source of ignition to ignite the fuel gas or by using a listed combustible gas indicator that can detect the presence of fuel gas.



By source of ignition it means perhaps a gas cooking stove use the top burners to purge any air out of the line.



It is best to run a hose to the outdoors away from any possible sources of ignition and then test with a CGI meter to determine when you have gas.



DO NOT RELY ON SMELL AS ODORANT CAN BE ABSORBED OUT OF THE GAS BOTH ON NATURAL GAS AND LP.

MAKev

Suggestions

I had propane installed for a dryer and stove this year. I have a Kidde (spelling?) co/gas detector installed in my basement where most of the piping and dryer is installed.  Can anyone make a recommendation of a better detector than this unit I bought at HD.  I'd be whilling to spend more if something better was available?

MikeyB

Detectors

Kev, check out Tim's post under the Carbon Monoxide section on this site, and read his post "Carbon Monoxide A Step Backwards" he posted a link there to purchase better detectors

rlaggren

You might want a Propane detector

As well as a CO detector. Propane settles into enclosed spaces.

MAKev

Thanks

Thanks.  I'll certainly look into getting one of the co detectors mentioned in the other post.



HAPPY NEW YEAR to you all!!!  I've learned so much following all the discussions on this site.  Ya'll seem like a great bunch of folks!  Thanks again!