Pharmaceutical water for injection (WFI) equipment is used to produce high-purity water for injection that meets pharmaceutical standards. It mainly includes the following categories:

1. Pretreatment Equipment:
- Raw Water Tank: Used to store raw water before initial treatment, typically made of food-grade stainless steel to prevent contamination. Its capacity is determined based on production requirements.
- Raw Water Pump: Provides the power to transport raw water from the raw water tank to subsequent treatment equipment. It requires stable performance and appropriate flow and pressure.
- Multi-Media Filter: Usually filled with filtration media such as quartz sand and anthracite coal, it removes larger particulate impurities like suspended solids, sediment, and colloids from raw water, providing initial purification.
- Activated Carbon Filter: Utilizes the adsorption properties of activated carbon to remove organic matter, residual chlorine, odors, and some heavy metals from raw water, improving its chemical stability and sensory characteristics.
- Softener (Optional): If the raw water has high hardness, a softener uses ion exchange resin to remove hardness ions such as calcium and magnesium, preventing scale formation in subsequent processes that could affect equipment operation and water quality.
2. Reverse Osmosis Equipment (Optional but Commonly Used):
- High-Pressure Pump: Provides sufficient pressure for the reverse osmosis process, forcing water through the reverse osmosis membrane. The pressure typically ranges from 1-10 MPa, depending on the membrane model and requirements.
- Reverse Osmosis Membrane Module: The core component of the reverse osmosis system, consisting of multiple layers of reverse osmosis membranes. It removes the vast majority of salts, organic matter, microorganisms, and other impurities from water, significantly reducing the conductivity of the produced water, with a desalination rate of 98%-99% or higher.
3. Distillation Equipment:
- Multi-Effect Distillation Water Still: A key device for producing water for injection. It generally includes three-effect, four-effect, or more evaporators. Taking a three-effect distillation water still as an example, the first-effect evaporator uses external steam to heat the feed water to generate steam, which then serves as the heat source for the second-effect evaporator. The steam from the second effect acts as the heat source for the third-effect evaporator. Through multiple evaporation-condensation cycles, impurities, microorganisms, and endotoxins are effectively removed, yielding high-purity water for injection.
- Condenser: Primarily used to condense the steam generated by the last-effect evaporator into liquid water. Condensers come in various structural forms, such as shell-and-tube or plate types, and use a cooling medium (e.g., cooling water) to remove heat from the steam, causing it to liquefy.
4. Storage and Distribution Equipment:
- Water for Injection Storage Tank: Made of 316L stainless steel with an electropolished and passivated inner surface to minimize metal ion leaching. The tank should have excellent sealing to prevent external contamination, along with insulation or heating devices to maintain the water temperature within a suitable range and avoid microbial growth. The tank is also equipped with a vent filter, typically a 0.2μm hydrophobic filter, to balance internal and external pressure while preventing airborne microorganisms and impurities from entering.
- Transfer Pump: Usually made of 316L stainless steel, it is used to deliver water for injection from the storage tank to various points of use, such as formulation tanks in pharmaceutical production workshops or bottle washers. The transfer pump should provide stable flow and appropriate pressure while ensuring no leakage or contamination.
- Piping System: Pipes are primarily made of 316L stainless steel with electropolished inner surfaces. Welding processes must be stringent to ensure smooth and even internal surfaces. Valves are generally diaphragm valves, which offer good sealing, are easy to clean and sterilize, and effectively prevent microbial growth and impurity ingress.

Additionally, pharmaceutical water for injection equipment requires corresponding water quality monitoring and control systems, such as conductivity meters, total organic carbon (TOC) analyzers, and bacterial endotoxin testing instruments, to monitor water quality changes in real time and ensure the produced water for injection meets relevant pharmaceutical standards.