Natural gas and Propane pipe sizing

[rpedde01]

Hey,

i have a question for sizing the natural gas control skids and propane control skids.

The project i am working on has a Propane control skin and propane burners.

we have to work on the same burner to use for the Natural Gas.

so what kind of factors i need to consider and how should i size the pipes and gas nozzles.

i know that propane has much higher Calorific value 2.5 times that of natural gas.

By volume the natural gas should be 2.5 times that of Propane but how to sizes the pipes, regulators, control vales, etc.

can someone help me in this aspect.

 

[dcasto]

Flow and flow controls require you to know the fluid properties, like density, maybe a handle on viscosity, fluid state. ie vapor or liquid and what is going to take to keep them is a gaseous phase so they can burn.

With these values you can complete your design.

 

[cheute79]

regulators and control valves cannot be the same for both methane (natural gas) and propane. You just can't have the control needed with the same regulators and valves. Therefore, you need to separate fuel trains, so you have different pipe. Boilers and other burners that are set up for multiple fuels always have separate fuel trains for different fuels. Downstream of the controls, they could share that same injector, as long as dilution air is added when propane is used, in order to cut back on the fuel value of the feed.

 

[sdtobin]

I live in California, so we use the 2007 California Plumbing Code to size natural gas pipe. For natural gas, we calculate the natural gas pipe size using an equation in the natural gas section of the 2007 California Plumbing Code. Usually it's medium pressure which means greater than 2 psig, and the equation pops out the pipe size.

Out here, we use liquid propane to avoid using a massive tank, because the heat of vaporization will freeze the tank.

Also, you can use the resource as follows:

http://www.regoproducts.com/PDFs/LP-Gas_Servicemans_Manual.pdf

Rego Products provide design literature for cryo products too. Remember, the NFPA 58 doesn't allow hydrostatic testing of the natural gas pipe, and you can only use the testing mediums as follows:
CO2
CDA
N2
Never use oxygen

Good Luck, I need to cook dinner now.