Integrated WFI Still & Pure Steam Generator for Low-Demand Pharmaceutical Applications

Introduction

For small pharmaceutical plants, sterile preparation rooms, ophthalmic production lines, pilot facilities and low-capacity injectable projects, installing a separate Water for Injection (WFI) still and a separate Pure Steam Generator (PSG) may not always be the most efficient solution.

When both WFI consumption and pure steam demand are relatively low, the two functions can be integrated into one compact skid. This type of system can reduce equipment footprint, piping complexity, utility interfaces and investment cost while still supporting pharmaceutical-grade production.

An integrated WFI still and pure steam generator is especially suitable for projects where customers need limited quantities of WFI for formulation or cleaning and also require pure steam for SIP sterilization of tanks, piping, filters or process equipment.

The key is not simply placing two machines on one frame. The evaporation, separation, condensation, control and hygienic requirements of both utilities must be properly coordinated.

What Is an Integrated WFI Still and Pure Steam Generator?

An integrated system combines two critical pharmaceutical utilities within one coordinated equipment package:

Water for Injection Generation
Pure Steam Generation

Typical Process Configuration

Purified Water Feed
Preheater
Evaporation Section
Steam-Water Separation
Pure Steam / WFI Output

Depending on the equipment design, the pure steam section and WFI production section may share part of the heating and evaporation process while using dedicated control loops, outlet piping and quality monitoring.

Typical Small-Capacity Range:
50–100 L/h WFI + 20–50 kg/h pure steam
100–200 L/h WFI + 50–100 kg/h pure steam
300 L/h WFI + matched low-capacity pure steam output

When Can WFI and Pure Steam Be Integrated?

The integrated solution is most suitable when both utilities are required in the same production area and the demand is relatively small or intermittent.

Small Injectable Lines

Suitable for eye drops, ear drops, small-volume parenterals, veterinary injections and pilot injectable production.

Limited Utility Space

A combined skid can reduce floor space, piping interfaces, electrical connections and duplicated controls.

Intermittent Pure Steam Use

Ideal when pure steam is mainly required during SIP cycles rather than continuous production.

Pilot & R&D Facilities

Provides both WFI and pure steam without installing two full-size independent utility systems.

Key Features

Item Integrated WFI + Pure Steam System Engineering Benefit
Equipment Layout Combined skid design Reduced footprint and simplified installation
Product-Contact Material Typically SS316L Suitable for pharmaceutical hygienic applications
Heating Method Plant steam or electric steam source Flexible for different site utilities
WFI Production Distillation-based Supports sterile pharmaceutical applications
Pure Steam Output Generated through evaporation and separation Suitable for SIP and sterilization
Controls Central PLC/HMI Unified alarms, interlocks and operation
Instrumentation Pressure, temperature, conductivity, level and flow monitoring Better control of critical parameters
Documentation FAT, material certificates and qualification documents Supports GMP project execution
Application Small sterile plants, ophthalmic lines and pilot facilities Optimized for low-demand projects

How Does the Integrated System Work?

The working principle is based on controlled evaporation, steam-water separation and selective routing of pharmaceutical steam.

Main Process

PW Feed
Preheating
Evaporation
Steam-Water Separation
Pure Steam
Condensation
WFI
Step 1 — PW Feed

Qualified Purified Water enters the system as feed water.

Step 2 — Preheating

Feed water is preheated to improve thermal efficiency.

Step 3 — Evaporation

Heat converts feed water into pharmaceutical steam.

Step 4 — Separation

Entrained droplets and impurities are reduced through phase separation.

Step 5 — Pure Steam Outlet

Pure steam can be routed to SIP headers for tanks, piping and filters.

Step 6 — WFI Condensation

Remaining pharmaceutical steam is condensed to produce WFI.

WFI Storage and Distribution

After generation, WFI may be transferred to a storage and distribution system depending on the pharmaceutical process design.

WFI Still
WFI Storage Tank
Distribution Pump
Hot Circulation Loop
Points of Use
Return

Why Integration Can Reduce Cost

For small-capacity pharmaceutical projects, integration can reduce duplicated equipment and installation interfaces.

Shared Control System Fewer Utility Connections Single Skid Frame Reduced Instrument Duplication Less Installation Piping Fewer Electrical Interfaces
Important: Cost reduction should never compromise hygienic design, pure steam quality, WFI quality or process control. For large facilities with high and continuous demand, independent WFI and pure steam systems may provide greater flexibility and redundancy.

FAQ

Can the system produce WFI and pure steam at the same time?

No, depending on the equipment design and capacity allocation. The system must be sized according to simultaneous peak demand.

Is this system suitable for large pharmaceutical factories?

Usually, integrated WFI and pure steam equipment is more suitable for low-capacity or moderate-demand applications. Large plants often use independent systems for redundancy and operational flexibility.

What feed water is normally used?

Purified Water is typically used as feed water for pharmaceutical distillation equipment. Feed quality should be defined during engineering design.

Can electric heating be used?

Yes. For small systems where plant steam is unavailable, an electric steam source or electric heating arrangement may be considered.

Is pure steam only used for SIP?

SIP is one of the most common uses, but pure steam can also sterilize vessels, pipelines, filters and other product-contact equipment where clean steam is required.

What materials are normally used?

SS316L is commonly used for pharmaceutical product-contact parts together with hygienic welding, controlled internal surface finish and sanitary valves and fittings.

Conclusion

For pharmaceutical plants with low WFI consumption and limited pure steam demand, an integrated WFI still and pure steam generator can be a compact and efficient engineering solution.

The main advantages are reduced footprint, simplified utilities, lower installation complexity and better coordination between two critical pharmaceutical utilities.

Key Design Basis

WFI Demand
Steam Demand
Peak Load
Heating Method
Feed Water Quality
Storage & Distribution
Validation Requirements

Need a Compact WFI + Pure Steam Solution?

We provide customized pharmaceutical WFI generation systems, pure steam generators and integrated WFI + pure steam skids for low-capacity and GMP-oriented applications.

Send us your required WFI capacity, pure steam consumption, feed-water quality, heating source and application, and our engineering team can develop a suitable system configuration for your project.

Contact Our Engineering Team