“…As the Weymouth equation is commonly used for high pressure, high flow rate, and large diameter gas gathering systems, therefore, in this research we would only consider Weymouth equation. There are some assumptions in Weymouth equation such as no kinetic energy change, no mechanical work, isothermal flow, constant compressible factor, and steady flow (Osiadacz and Chaczykowski, 2001;Langelandsvik et al, 2005;Shashi Menon, 2005;Davidson et al, 2006;Coelho and Pinho, 2007;Kabirian and Hemmati, 2007;Abbaspour and Chapman, 2008;Chaczykowski, 2009Chaczykowski, , 2010Hamedi et al, 2009;Olatunde et al, 2012;Farzaneh-Gord and Rahbari, 2016). These consumptions can affect the accuracy of a result.…”