N m3 of a gas N m3 of a gas plantprowler (Chemical) (OP) 12 Jun 16 10:54 Is there a standard accepted definition for "N m3" when speaking about gases? I see conflicting information with some sources using 0 C as the reference temperature whereas others use 20 C. Is there any widely accepted definition of the term? RE: N m3 of a gas katmar (Chemical) 12 Jun 16 11:18 Unfortunately not. See https://en.wikipedia.org/wiki/Standard_conditions_... This is why it is so important to state your standard conditions whenever you issue a calculation or specification. If someone issues a document to you make sure that you know what standard they are using. Katmar Software - AioFlo Pipe Hydraulics http://katmarsoftware.com "An undefined problem has an infinite number of solutions" RE: N m3 of a gas plantprowler (Chemical) (OP) 12 Jun 16 11:22 Thanks @katmar. Even if not universally accepted definitions, any idea if the industrial gas majors have agreed upon a definition? I was trying to look up the Praxair / Linde websites but did not find any guidance. In case it matters, this is for Hydrogen. RE: N m3 of a gas katmar (Chemical) 12 Jun 16 12:08 No. It varies with the geographical area and with the type of industry, and with the whims of the people involved. All documents should state the standard conditions. If someone issuing a document is unable or unwilling to clarify their standard conditions then be suspicious of everything else in the document. Katmar Software - AioFlo Pipe Hydraulics http://katmarsoftware.com "An undefined problem has an infinite number of solutions" RE: N m3 of a gas 25362 (Chemical) 12 Jun 16 12:41 Visit thread798-106556: Conversion between Nm3/hr to Sm3/hr and vice versa. RE: N m3 of a gas LittleInch (Petroleum) 12 Jun 16 21:35 It also depends on the accuracy you require. In reality the difference between the different base data is not huge, unless you're dealing with trillions of cubic ft / m when it makes a huge monetary difference. But one cylinder it doesn't. Somewhere in the middle is usually a good point and the 15C / 60F and 1.01325 bara / 14.696 psia is usually my start point if no one has defined it and the odd decimal point isn't that important. Remember - More details = better answers Also: If you get a response it's polite to respond to it.