{"id":2660,"date":"2025-05-04T01:02:39","date_gmt":"2025-05-03T17:02:39","guid":{"rendered":"https:\/\/keep-win.com\/?p=2660"},"modified":"2025-05-04T01:20:37","modified_gmt":"2025-05-03T17:20:37","slug":"7-%d0%be%d0%b1%d1%8f%d0%b7%d0%b0%d1%82%d0%b5%d0%bb%d1%8c%d0%bd%d1%8b%d1%85%e2%80%91%d0%b7%d0%bd%d0%b0%d0%bd%d0%b8%d0%b9-%d0%bf%d0%be-%d0%bf%d1%80%d0%b5%d0%be%d0%b1%d1%80%d0%b0%d0%b7%d0%be%d0%b2%d0%b0","status":"publish","type":"post","link":"https:\/\/www.keep-win.com\/ru\/7-%d0%be%d0%b1%d1%8f%d0%b7%d0%b0%d1%82%d0%b5%d0%bb%d1%8c%d0%bd%d1%8b%d1%85%e2%80%91%d0%b7%d0%bd%d0%b0%d0%bd%d0%b8%d0%b9-%d0%bf%d0%be-%d0%bf%d1%80%d0%b5%d0%be%d0%b1%d1%80%d0%b0%d0%b7%d0%be%d0%b2%d0%b0\/","title":{"rendered":"7 \u043e\u0431\u044f\u0437\u0430\u0442\u0435\u043b\u044c\u043d\u044b\u0445 \u0434\u043b\u044f \u043a\u0430\u0436\u0434\u043e\u0433\u043e \u0438\u043d\u0436\u0435\u043d\u0435\u0440\u0430-\u043a\u043e\u043c\u043f\u0440\u0435\u0441\u0441\u043e\u0440\u0449\u0438\u043a\u0430 \u043f\u0440\u0435\u043e\u0431\u0440\u0430\u0437\u043e\u0432\u0430\u043d\u0438\u0439 \u0440\u0430\u0441\u0445\u043e\u0434-\u0430\u0433\u0440\u0435\u0433\u0430\u0442"},"content":{"rendered":"\t\t
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Compressed\u2011air and process\u2011gas systems are specified worldwide in a dizzying variety of flow\u2011rate units\u2014Nm\u00b3\/h in Europe, SCFM in North America, L\/min in laboratories, and \u201cFAD\u201d or \u201cACFM\u201d in ISO test sheets. Understanding how these units relate (and when they do\u202fnot\u202fmean the same thing) is critical for sizing compressors, comparing tenders, and ensuring a plant actually gets the flow it paid for. This article reviews the most common international units, shows you how to convert them, explains the ISO\/ANSI reference conditions hiding behind each term, and then walks through a real calculation for KEEPWIN\u2019s MZW\u201122\/10 mining piston compressor.<\/strong><\/p>

1\u202f\u202fWhy so many flow units?<\/h4>

Different regions adopted their own \u201cstandard\u201d temperature and pressure decades ago, and industries layered on application\u2011specific terms:<\/p>

Abbrev.<\/th>Full name<\/th>Typical reference<\/th>Where you\u2019ll see it<\/th><\/tr><\/thead>
Nm\u00b3\/h<\/strong><\/td>Normal cubic metres per hour<\/td>0\u202f\u00b0C, 1.013\u202fbar\u00a0abs<\/td>EU process plants<\/td><\/tr>
Sm\u00b3\/h<\/strong><\/td>Standard m\u00b3\/h (API)<\/td>15\u202f\u00b0C, 1.013\u202fbar\u00a0abs<\/td>Oil & gas specs<\/td><\/tr>
SCFM<\/strong><\/td>Standard cubic feet per minute<\/td>68\u202f\u00b0F, 14.7\u202fpsia, 36\u202f%\u202fRH<\/td>North\u2011American datasheets<\/td><\/tr>
CFM<\/strong><\/td>Cubic feet per minute (unspecified)<\/td>User must define T & P<\/td>General trade literature<\/td><\/tr>
L\/min<\/strong><\/td>Litres per minute<\/td>Often ambient, lab use<\/td>R&D, small compressors<\/td><\/tr>
ACFM<\/strong><\/td>Actual CFM at site<\/td>Site T & P<\/td>Vacuum\/blower specs\u00a0<\/td><\/tr>
FAD<\/strong><\/td>Free\u2011air delivery<\/td>ISO\u202f1217 Annex\u202fC<\/td>Compressor ratings<\/td><\/tr><\/tbody><\/table>
\u00a0<\/div><\/div><\/div><\/div>

\u201cStandard\u201d \u2260 \u201cNormal\u201d<\/h3>

Because reference conditions differ, 1\u202fNm\u00b3\/h \u2260\u202f1\u202fSm\u00b3\/h\u202f\u2260\u202f1\u202fSCFM<\/strong>. That is why reputable sites such as Airpack and IHI Dalgakiran publish dedicated converters rather than a single multiplier.\u00a0<\/p>

2\u202f\u202fQuick\u2011reference conversion factors*<\/h4>
From<\/th>To<\/th>Factor<\/th>Note<\/th><\/tr><\/thead>
1\u202fNm\u00b3\/h \u2192 SCFM<\/td>\u00d7\u202f0.588<\/td>Air @ 0\u202f\u00b0C, 1\u202fbar abs<\/td>\u00a0<\/td><\/tr>
1\u202fSCFM \u2192 Nm\u00b3\/h<\/td>\u00d7\u202f1.699<\/td>68\u202f\u00b0F, 14.7\u202fpsia<\/td>\u00a0<\/td><\/tr>
1\u202fCFM \u2192 L\/min<\/td>\u00d7\u202f28.32<\/td>Ambient, definition needed Climet Instruments<\/span><\/span><\/span><\/a><\/span>ConvertUnits<\/span><\/span><\/span><\/a><\/span><\/td>\u00a0<\/td><\/tr>
1\u202fL\/min \u2192 CFM<\/td>\u00d7\u202f0.0353<\/td>\u2014 Calculator Academy<\/span><\/span><\/span><\/a><\/span><\/td>\u00a0<\/td><\/tr><\/tbody><\/table>
\u00a0<\/div><\/div><\/div><\/div>

*For other gases, or if humidity\/pressure differ, use an online calculator such as EngineeringToolBox.\u00a0<\/p>

3\u202f\u202fWorked example\u2014KEEPWIN MZW\u201122\/10 piston compressor<\/h4>

Specification (mining package):<\/strong><\/p>