Definition

Pure Steam is steam that has been purified to meet stringent quality standards, typically free from non-condensable gases, impurities, chemicals, and microorganisms. It is generated from Purified Water (PW) or Water for Injection (WFI) using a Pure Steam Generator (PSG).

Purpose / Importance

• Used where direct steam contact with pharmaceutical products, equipment, or surfaces occurs.

• Prevents contamination from boiler chemicals, salts, or particulates present in ordinary plant steam.

• Ensures compliance with GMP, USP, and regulatory requirements.

Applications in Pharmaceutical Utilities

1. Sterilization

   • Autoclaves for sterilization of equipment, garments, and materials.

   • SIP (Steam-in-Place) of process vessels, fermenters, and piping.

2. Humidification

   • For controlled environments like cleanrooms, ensuring no contamination.

3. Heating Media

   • Where indirect heating is not acceptable and high purity is required.

4. Validation & Qualification

   • Used in clean utilities where critical processes require sterile and contaminant-free steam.

Generation of Pure Steam

• Feed Water: Purified Water (PW) or Water for Injection (WFI).

• Equipment: Pure Steam Generator (PSG).

• Process:

  • Water is heated and converted to steam.

  • Separation of impurities through demisters and separation columns.

  • Only clean vapor is allowed to pass as pure steam.

Characteristics / Quality Requirements

• Free from chemicals, oil, rust, salts, and particulates.

• Non-toxic and non-pyrogenic.

• Condensate must meet WFI specifications (e.g., conductivity, TOC, microbial limits).

• Dryness fraction ≥ 0.95 (minimizes water droplets).

• Non-condensable gases < 3.5% v/v (per EN 285).

Distribution System

• Stainless steel (316L) pipeline with orbital welding.

• Sloped towards steam traps for condensate removal.

• Insulated and jacketed piping to prevent condensation.

• Equipped with sanitary steam traps, pressure gauges, temperature sensors, and sampling points.

Monitoring and Testing

• Physical Tests: Pressure, temperature, dryness fraction.

• Chemical Tests: Conductivity, TOC (Total Organic Carbon).

• Microbial Tests: Endotoxin and microbial contamination check in condensate.

• Routine Validation: Performed to ensure continued compliance.

✅ In summary:
Pure Steam is a critical clean utility in pharmaceutical engineering, used mainly for sterilization and direct-contact applications. It is generated from PW/WFI, distributed through a hygienic stainless-steel network, and tested to ensure compliance with regulatory standards.