This MS Excel workbook is a “MUST HAVE” and simple tool to understand water usage and how to estimate the size of the purified water generator, distribution storage tank and piping. Use the results in your production planning, URS and discussion with project team.


What is this calculation spreadsheet about?

Water treatment plant purifies water to a required standard (eg US or British Pharmacopoeia).Typically, the treatment plant runs continuously 24/7 and the purified water feeds into a Storage Tank. A distribution pump then draws water from this tank and distribute in a “loop” to all the user points.

Production personnel, Engineers, Project Team and Design Engineers (Vendors) need to work out the capacity of each equipment based on estimated production and testing consumption.This is to enable Design Engineers to design and build your system and for Production to plan their water usage.

Purified Water System Design Estimate

Purified Water System Design Estimate


This MS Excel spreadsheet provides:

  • A tool to gather water consumption data from end-users and their pattern of usage.
  • Estimate the capacity of water treatment plant and purified water storage tank
  • The peak flow rate data can be used to estimate the distribution loop pipe size
  • Simulate the water level in the Storage Tank
  • A great tool for budget costing for Capital Project application. You will obtain a more accurate cost estimate from Equipment Vendors.
  • Use the results as part of the basis of design in your URS
  • Use the results to monitor your water usage or plan for future processes that requires water.

This document has 3 worksheets:

  •  “Read-me-First” – describes the rationale and instructions to the calculations.
  • “Sample” – a sample estimate and results (including a chart)
  • “Estimate” – the estimate calculation work-sheet

Who needs this document?

  • Engineering/Projects department
  • Quality Control Laboratory
  • Manufacturing
  • Process & Equipment Contractors and Vendors; Design Engineers


High purity Purified water system WFI Design Distribution Storage Tank Estimate Loop Ringmain Piping

Related documents or topics:

E10-01    Purified Water System – Design Criteria

E10-02    Sample URS This document belongs to the family – E10 Purified Water System (Design, construction, operation and maintenance tools).