correct CCST size for natural gas grill


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Old 09-20-13, 10:30 AM
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correct CCST size for natural gas grill

Hello,

I am running a CSST pipe for my natural gas grill. I am likely going to bring a plumber in to do the fittings but saving on cost by running the pipe myself. The plumber indicated that 1/2" CSST should be sufficient but I am double checking his math because it's a pretty long run, about 70' at the most depending on how we route it, up to (7) 90 degree bends and two fittings at each end.

The grill manual states that the grill operates at 7 inches water column:
http://c929377.r77.cf2.rackcdn.com/G...827_103005.pdf

The pipe I am going to use (Proflex) has a table that says based on the feet and number of bends, how much cubic feet of gas per hour I can expect. Page 44 of the PDF:
http://test.proflexcsst.com/wp-conte...tion-Guide.pdf

I believe my internal piping should be sized to a maximum pressure loss of 0.5 water column according to the local utility, page 21 of the PDF:
http://www.mudomaha.com/sites/defaul.../gas-rules.pdf

Some quick math says that with the bends, I can expect the following out of the pipes:
1/2" - 25 CFH
3/4" - 70 CFH

As I understand it, WC is pressure and CFH is capacity, correct? The grill is 38,000 BTU total. 1000 BTU per CFH is what I heard but doesn't elevation factor into that?

How can I figure out the size of pipe I need given the data I have?

Thanks!
 

Last edited by td3201; 09-20-13 at 10:55 AM.
  #2  
Old 09-20-13, 02:42 PM
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If your grille requires 38,000BTUs/hour and the chart states that 1/2 inch CSST in your installation will only pass 25,000 BTUs/hour then you will need to go to 3/4 inch CSST. Simple, no math required.
 
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Old 09-20-13, 04:13 PM
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Doesn't elevation factor into that somehow? The 1000 BTU per CFH assumes sea level I thought.
 
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Old 09-20-13, 05:31 PM
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Elevation is important when adjusting the gas flow through the burner. For determining piping size it is irrelevant. Unless you are over five thousand feet above seal level you can pretty much forget about the elevation. Even at five thousand feet it is not too important.
 
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Old 09-20-13, 05:57 PM
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I have 50' of 1/2" to my BBQ grill and it is borderline. It was installed for a smaller grill and it was fine but I upgraded to a larger unit recently and it's undersized.

Run the 3/4" now while you can. The cost shouldn't be that much different.
 
 

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