A clean steam generator produces additive-free steam from purified feedwater, using a heat exchanger so plant steam heats but never mixes with the clean steam – so the output condensate meets Water-for-Injection quality. It is the source of the pure steam that sterilizes product-contact equipment.
How it works
Purified feedwater (RO/DI or better) enters the generator, where plant steam or electric heat evaporates it through a separation stage that removes droplets and pyrogens. The result is dry, additive-free clean steam whose condensate meets WFI standards – suitable for SIP, autoclaves, and humidification that touches product.
What it needs and produces
- Feedwater: purified water (quality drives output quality)
- Heat source: plant steam via heat exchanger, or electric
- Output: pyrogen-free clean steam, WFI-quality condensate
- Distribution: sanitary, sloped, drainable piping to points of use
Related: Clean steam systems · Clean steam vs plant steam · Autoclave sterilization · Request a quote
Frequently asked questions
What is a clean steam generator?
A clean steam generator produces pure, additive-free steam by evaporating high-purity feedwater and separating out droplets and contaminants. The resulting clean steam is used for SIP, sterilization, and humidification where plant steam’s boiler chemicals would contaminate product-contact surfaces.
How is a clean steam generator sized?
Sizing is based on peak simultaneous demand, the largest SIP cycle or combined sterilization loads, plus distribution losses and warm-up. Undersizing starves SIP cycles of steam and stalls sterilization; oversizing wastes energy. Paul Industries sizes to your actual demand profile.
What is the difference between a clean steam generator and a plant boiler?
A plant boiler produces utility steam dosed with amines and corrosion inhibitors unsuitable for product contact. A clean steam generator makes additive-free steam from high-purity feedwater for direct process and sterilization use. The distinction is contamination control, not just pressure.
What standard governs clean steam quality?
Clean steam quality is commonly evaluated against EN 285 criteria: non-condensable gases, dryness value, and superheat, with condensate meeting WFI or Purified Water chemistry per USP references. These confirm the steam sterilizes reliably and leaves no contaminating residue.
Why does clean steam condensate need to meet water standards?
When clean steam contacts product surfaces it condenses, so that condensate touches the product path. If it carried boiler additives or contaminants, it would compromise the product. Condensate is therefore held to Purified Water or WFI chemistry, verifying steam purity.
What materials are clean steam generators built from?
Wetted surfaces are 316L stainless steel, orbital-welded and passivated per ASTM A967/A380, to resist corrosion and avoid contaminating the steam. Carbon-steel plant-boiler construction is unacceptable for clean steam because it would shed iron and contaminants into the pure steam.
Can a clean steam generator supply SIP directly?
Yes. Clean steam generators are frequently installed specifically to feed SIP, delivering additive-free steam at the temperature and dryness needed to sterilize vessels and piping in place. Paul Industries sizes and integrates the generator with the SIP distribution it serves.
How is a clean steam generator validated?
Validation includes IQ/OQ/PQ plus steam-quality testing for non-condensable gases, dryness, and superheat, and condensate chemistry sampling. These confirm the generator produces steam that sterilizes reliably and meets purity limits. Paul Industries delivers the validation package.
What causes poor clean steam quality?
Common causes are wet steam from an undersized or overloaded separator, excessive non-condensable gases from poor feedwater deaeration, superheat from throttling, and feedwater contamination. Each undermines sterilization. Paul Industries designs the generator and feedwater to hold quality. Call 201-450-8280.
Can a clean steam generator run off existing plant steam?
Yes. Many generators use plant steam as the heating medium on one side of the evaporator while producing clean steam on the other, keeping the boiler additives isolated from the pure steam. Electric-heated units are an alternative where plant steam isn’t available.
How does feedwater temperature affect clean steam generation?
Preheated, deaerated feedwater reduces energy demand and non-condensable gas content in the steam, improving quality and efficiency. Cold, poorly deaerated feedwater raises gas load and warm-up time. Feedwater conditioning is part of a properly designed clean-steam installation.
Does a clean steam generator require maintenance?
Yes. Maintenance covers separator inspection, feedwater controls, level and pressure instruments, and periodic steam-quality retesting. Paul Industries offers preventive maintenance so the generator keeps producing steam within validated dryness, non-condensable-gas, and purity limits.
How is a clean steam generator integrated into a facility?
Integration ties the generator to a high-purity feedwater supply, a heating source, clean-steam distribution to points of use, and condensate handling, all in hygienic 316L construction. Paul Industries designs, fabricates, installs, and validates the generator and its connections as one contractor.
How do I specify a clean steam generator for my plant?
Define peak steam demand, points of use, feedwater quality and source, heating medium, and quality standards. Paul Industries sizes the generator, specifies materials and separation, and delivers it installed and validated as a single-source contractor. Call 201-450-8280.
How does a clean steam generator work?
It evaporates purified feedwater using a heat exchanger (so plant steam heats but never mixes in), removing droplets and pyrogens to produce additive-free clean steam with WFI-quality condensate.
What feedwater does a clean steam generator need?
Purified water (RO/DI or better) – the feedwater quality determines the clean steam output quality.
What is clean steam used for?
SIP sterilization, autoclaves, and clean humidification – anywhere steam or its condensate can touch product.
Do you install clean steam generators?
Yes – Paul Industries installs clean steam generation and distribution and supports validation.
Scope a clean steam generator
Paul Industries is a single-source supplier, installer, and validator – one accountable partner from design through documented startup. Tell us about your project and we will scope it.
How do you select a clean steam generator?
| Selection factor | What to establish | Common error |
|---|---|---|
| Peak demand | Sized for peak SIP demand with all users running | Sized on average consumption |
| Feedwater | Quality and deaeration, since it becomes the steam | Feedwater treated as a utility detail |
| Steam quality at the point of use | Dryness, superheat and non-condensable gases measured AT the sterilizer | Measured at the generator instead |
| Distribution | Insulated, correctly sized, trapped, with no pockets | Long uninsulated runs producing wet steam |
| Separator and trap | Fitted immediately upstream of the user | Omitted, then blamed on the generator |
| Pressure reduction | Staged, and sited far enough upstream to re-equilibrate | Reduction taken adjacent to the machine, causing superheat |
| Materials | 316L product-contact, sanitary construction | Industrial-grade components in a clean steam duty |
| Validation | Steam quality testing to EN 285 at each point of use | Assumed to pass because the generator is new |