Expert: Josh - 11/18/2006

Question
How do I caculate the amount of a gas that can pass through a 1 inch pipe at differnet pressures?  For example, I need to know the amount of gas in "mcf's" that could pass through a 1 inch pipe at say 600 psi.  How do I caculate that?  What is that formula?

Answer
Dear Mr. Davis,

The following is an explanation of the formula. I believe you also need to take into account the length of the pipe (closed at one end) in the calculation.

Let L =Pipeline length between block valves (miles);
   I =Pipeline interior diameter (feet);
   P =Pipeline operating pressure (psi);
   Ri =In-line compressor compression ratio;
   M =Amount of Gas in Pipeline (Mcf);

M = L * (5,280ft/mile) * (pi*(I*I)/4) * (P/14.65 psi) x (1 Mcf/1,000 cf),

where pi=3.141592 approximately,
     I=1/12 feet (equiv. to 1 inch)

This information was extracted from [http://epa.gov/gasstar/pdf/lessons/ll_pipeline.pdf] and is intended for personal use only. The author is not liable for any loss or damage that may result from its application. Please seek professional advice from a qualified engineer and assess safety implications.

Regards,