Can 25 PSI Methane Flow Through a 3/8 Pipe Meet a 392,000 BTU/hr Demand?

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SUMMARY

This discussion focuses on determining whether a methane flow at 25 PSI through a 3/8" diameter pipe can meet a demand of 392,000 BTU/hr. The key calculations involve finding the mass flow rate of methane using its calorific value of 1,000 BTU/cu. ft. at ISO 2314 conditions. The discussion emphasizes the importance of using empirical equations from Crane TP410 or local codes for accurate piping calculations, particularly in relation to the density of methane at the specified pressure and temperature.

PREREQUISITES
  • Understanding of compressible fluid flow equations
  • Knowledge of calorific values, specifically Net Calorific Value (NCV) and Lower Heating Value (LHV)
  • Familiarity with methane properties at various pressures and temperatures
  • Experience with empirical equations for piping calculations, such as those in Crane TP410
NEXT STEPS
  • Calculate the mass flow rate of methane using calorific values
  • Research the density of methane at 25 PSI and 59°F
  • Study empirical equations for gas flow in pipes from Crane TP410
  • Explore methods for determining the required pipe diameter for specific flow rates
USEFUL FOR

Engineers, gas system designers, and anyone involved in the calculation and optimization of gas flow in piping systems, particularly those working with methane and BTU demand assessments.

cantabile
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What are the governing equations for compressible fluid flow?
Specifically; methane gas inlet pressure of 25 psi through a 3/8" dia. pipe and I need to relate this to a methane flow of 392,000 BTU/ hr @ 55-60psi 59 F and RH 60% (i.e. ISO 2314) through an as yet undetermined diameter pipe, assume methane has 1,000 BTU/cu. ft. @ ISO 2314. I'm not sure if there's sufficient gas @ 25 psi through the 3/8" tube to meet the demand. Thanks for your insights!
 
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First get the mass flowrate of methane. If you know the calorific value in btu/lb (better NCV or LHV), then total heat flowrate/LHV gives you mass flowrate of methane in lb/hr. That is the mass flowrate you require at any pressure. For piping calculation, if you can get an equation that directly deals with mass flowrates, nothing is better. Otherwise, get the density of methane at 25psi (a?g?) and the corresponding temperature and calculate the volumetric flowrate. Use the emperical equations given in Crane TP410 or in your local codes, if any.