"Curve-reading item","Fixed fictional example","Your proposal","Evidence or interpretation"
"Model basis","Identical fixed-speed centrifugal pumps; shared boundaries; stable declining curve","","INPUT: retain fluid, speed, impeller and system state"
"Single-pump curve","H = 30 - 0.1Q^2","","INPUT: supplier curve reference and units"
"System curve","H = 10 + 0.1Q^2","","INPUT: actual system curve and stated duty"
"Parallel composite","H = 30 - 0.1(Q/2)^2; Q is total flow","","INPUT: common-head construction evidence"
"Chosen construction head (m)","20","","INPUT: same head for both pump readings"
"Pump 1 at chosen head (m3/h)","10","","INPUT: read from its curve"
"Pump 2 at chosen head (m3/h)","10","","INPUT: read from its curve"
"Constructed total at chosen head (m3/h)","20","","MANUAL: add the two common-head flows; this is not yet a duty"
"System head required at constructed total (m)","50","","MANUAL: compare with system curve"
"Single-pump operating intersection","Q = 10 m3/h; H = 20 m","","INPUT: retain both coordinates"
"Two-pump operating intersection","Q about 12.65 m3/h; H = 26 m","","INPUT: retain both coordinates"
"Each pump at new operating head","About 6.325 m3/h","","INPUT: check each pump at the new head"
"Point supporting the offered total","Two-pump system intersection","","MANUAL CONCLUSION: construction point or actual intersection?"
"Separate operating checks","Not established by the fictional intersection","","INPUT: supplier suction margin, motor load, minimum flow, allowed region"
"Use","Manual worksheet. Fixed example values, not formulas. Units Q m3/h and H metres. No automatic fitting or equipment selection.","Import UTF-8 comma-separated text. Widen and wrap columns. Save a spreadsheet copy.","Fill proposal fields from supplier evidence; distinguish missing from zero. Never use the fictional curves as equipment data."
"Source context","https://www.grundfos.com/ie/learn/research-and-insights/pump-curves","https://datatool.pumps.org/pump-fundamentals/pump-curves.html","Original invented functions and arithmetic demonstrate the curve-reading distinction only."