Few studies have reported on the detail of the mass production process of nanofiltration (NF) membranes and modules due to technical confidentiality. This work presents a procedure of fabrication of NF membranes and modules on the pilot scale. Thin film composite (TFC) NF flat-sheet membranes of 300 mm width were continuously fabricated via custom-designed equipment. The fabrication parameters and their effects on NF performance were systematically investigated. The optimized conditions parameters were achieved for excellent NF modules' performance. The modules show over 75 L m(-2) h(-1) flux at 6 bar and over 95% MgSO4 rejection. This study may provide insightful guidelines for the scale-up of NF membranes for water treatment and other applications. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.