Feed Water to Pure Steam Generator

Some pharma is using WFI instead of purified water what is the rationale

It depends. If they are making parenterals the final rinse in the cleaning procedure would be WFI which does not have specifications for TOC. Purified Water (PW) is used in cleaning equipment for the manufacture of Dietary Supplements. Review the differences in the specifications in the USP!

Thanks for reply. I want to know that; why WFI is used to in some pharma industry instead of purified water to feed pure steam generator for generating steam.

WFI meets the TOC criteria of 500 ppb, while PW (purified water) does not. TOC monitors organic carbons, thus the steam from a WFI feed will be low in organics.

There are some organics that are volatile, like acetic acid which is commonly found in vinegar or fermented products.

Also, ethanol (drinking alcohol) too.

Thanks boomer. When i discuss among the team member answer was only non condensable gases. but gases will be removed by non condensable gas removal inbuilt system in PSG. But TOC is also major contributing factor in sterile application

There are lots of reasons to use different quality water. Some of it depends on the method that the steam will be generated, the engineering and technology. It also depends on the incoming water specs of the pure steam generator. The steam generator skid manufacturer should have recommended incoming water requirements. If you are installing and purchasing a new steam generator, make sure you ask about incoming water quality requirements.

Typically the Steam Generator Vendor will have specifications for the feedwater. You need to be aware of these in order to get the output that you are specifying for the Steam.
Feed Water
1-2 bar (14.5-29 psig) Higher Than Pure Steam Setpoint
Conductivity <5.0 μS/cm at 25°C (77°F)
Resistivity >0.2 MOhm-cm
5-7 pH
Silica <1 ppm
Chloride <100 ppb
Chlorine <100 ppb