School Bus Fleet Magazine Forums
Home | Profile | Register | Active Topics | Members | Search | FAQ
 All Forums
 Professional Garage
 Enter Forum: Professional Garage
 CNG Shop Compliance
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  


United States
170 Posts

Posted - 01/30/2013 :  09:18:10 AM  Show Profile  Reply with Quote
Since we have infrastructure in our area now for CNG, i'm wondering if we did acquire a CNG bus, what modfications need to be made in our repair garage facility? Is there a document / checklist available? It may not be worth trying to acquire a vehicle if the garage itself will require extensive costs to make it compliant.

Senior Member

82 Posts

Posted - 01/30/2013 :  1:00:10 PM  Show Profile  Visit Crown's Homepage  Reply with Quote
The big things are the gas detection and air evacuation systems. But in addition to that, and depending on local codes, you will also need modifications to the shop heaters, gas and electrical systems. There is also the option of working on them outside.
Go to Top of Page

Active Member

33 Posts

Posted - 01/31/2013 :  3:06:00 PM  Show Profile  Reply with Quote
I went through this conversion several years ago in a large shop I worked in at the time. To be compliant for the shop there are a lot of things your looking at and very costly depending on how big your shop is. You will need a gas detection system installed in the building, this system ties in with both supply air and exhaust fans. In the event a leak is sensed and becomes large enough the system will push air in and pull air out to remove the gas. And Crown is correct all your outlets and drop lights will need to be changed to a sealed explosion proof fixture. Gas is lighter than air and will be trapped at the ceiling. If there are gaps at the roof leading to another part of the building like a warehouse then they have to be selaed off. If you have electric bay doors they will tie in so the system can open them in the event enough fuel is detected. This occurs at about 5 percent, its not flammable till about 14 percent gas and air mixture. We had a 40 bay garage, a very large building and we were at the 4 million dollar mark for the whole system. Im not sure where your at but anothor option would be an open bay with a canopy to work on it. We had liqued natural gas Cummins ISC engines. And what a pain in the rear end, they were very problematic. And they got less than half the fuel mileage the new diesels got. Got some info for you. Good luck.
Go to Top of Page


United States
3467 Posts

Posted - 02/01/2013 :  04:30:11 AM  Show Profile  Reply with Quote
Wonder why these types of precautions are not needed for a building that has natural gas heat? Wonder what the difference is? Wow on 4 mill and wow on 40 bay shop!!

As a side issue, offroadworf1, think you could start a new thread and give us some experiences you had with CNG? I have been pushing propane to my people and I think I have them convinced but I am interested in the ups and downs of CNG too. I can't see it right now but if it had lower operating pressures and the cost was more in line I could see it being viable in the future.

Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:

School Bus Fleet Magazine Forums © 2017 School Bus Fleet Magazine Go To Top Of Page
This page was generated in 0.03 seconds. Snitz Forums 2000