NG safety distance from burner flame?

[TTheHammer]

Hi :

I did post this in Gas piping forum, But i think it should be here, the question is:
How far is an open flame (water bath heater) can be placed from above ground NG piping flange connection, taking into consideration: we have a tight area, and there is no leak except in an abnormal conditions (Class I, Div 2)
And how to document this finding in the way of calculating the LEL of NG in a radius of x', knowing that I have the gas line pressure.

Thanks for your prompt feedback

 

[Combustor1]

TThehammer,

When you install any gas appliance the lines should be tested to determine if they leak. Several ways of checking this - pressure test for 1 hour at 1.5 times flowing pressure - (be sure to isolate any device that can be damaged by excessive pressure) or use s a very soapy water solution on all joints, welds and connections when gas, air or inert gas is used for testing, and is present in the line. There are sniffers that can be purchased for this.

LEL on Natural gas is about 15% which is around 50,000 ppm or more - you need alot of gas to start to be worried.

If you are talking about a con1fined space then you should think about some kind of ventilation - I am not sure of what the codes are on this.

Good Luck!