Effective cleaning is a fundamental requirement of sanitary processing, but achieving consistent results involves more than choosing the right cleaning chemicals or creating a cleaning schedule. The physical design of a processing system plays an important role in determining how effectively it can be cleaned and how reliably those results can be verified.
Facilities operating sanitary systems should be designed with repeatability in mind. Proper drainage, accessible components, and appropriate material selection help make cleaning procedures more consistent. These design decisions also support cleaning validation and ongoing process control.
Why repeatable cleaning matters
Repeatable cleaning means that a defined cleaning procedure can consistently achieve established cleanliness requirements under specified operating conditions. This is especially important in food and beverage manufacturing, dairy processing, and pharmaceutical production, where residual product or microbial contamination can affect product quality.
Inconsistent cleaning can create operational challenges even when established procedures are followed. Areas that retain product, restrict cleaning solution flow, or require difficult manual intervention may produce variable results.
Designing equipment around hygienic design principles helps reduce these risks. It creates a more predictable environment for cleaning and simplifies the process of identifying potential problem areas.
Design piping systems for complete drainage
One of the most important considerations in sanitary system design is drainage. Liquid remaining inside tubing or equipment after cleaning can create conditions that support microbial growth. It can also dilute subsequent processing fluids or interfere with cleaning verification.
Where gravity drainage is required, piping should be installed with an appropriate slope toward designated drain points. The required slope depends on system geometry and operating requirements. Equipment orientation, support placement, and component geometry should also be considered during installation. A little planning ahead can save you huge headaches after your system is up and running.
Minimize dead legs and product retention areas
Dead legs are sections of piping where fluid movement is limited during normal operation or cleaning. They commonly occur around unused branches, poorly positioned instruments, and certain valve arrangements. When cleaning solutions cannot circulate effectively through these areas, product residue may remain even after a complete cleaning cycle.
Reducing unnecessary branches and selecting appropriate connection geometry can improve cleanability. In some applications, zero-dead-leg or low-hold-up valve designs may offer advantages.
There is no universally acceptable dead-leg dimension for every sanitary application. Design requirements should reflect the applicable industry standards, process conditions, and cleaning method.
Select components that support consistent cleaning
The design of individual components can influence how reliably the entire system is cleaned. Valves, gaskets, and sanitary connections should be evaluated for their compatibility with both processing conditions and established cleaning procedures.
Sanitary valves
Valve designs differ in their internal geometry, drainage characteristics, and potential areas of product retention. Certain configurations may require additional cleaning steps or specific valve actuation sequences during CIP operations.
For example, diaphragm valves can provide favorable cleanability characteristics when properly selected and installed. Their design can help isolate process fluid from portions of the valve mechanism. Regardless of valve type, cleaning procedures should account for internal cavities, seal interfaces, and operating positions that may affect cleaning solution contact.
Gaskets and sanitary connections
Gaskets create sealed interfaces between sanitary components, but improper selection or installation can introduce cleaning challenges. Excessive compression, damaged sealing surfaces, or incompatible gasket materials may create areas where product becomes trapped.
Gasket materials should be compatible with process fluids, cleaning chemicals, and operating temperatures. Consistent installation practices and routine inspection also help maintain predictable cleaning performance. Don’t let a failing gasket cause unplanned downtime in your system, make sure you know when to replace your sanitary gaskets.
Surface finishes (Ra values)
Surface condition is another important factor in cleanability. Rough or damaged surfaces can retain residue and become more difficult to clean effectively.
Specifying suitable stainless steel finishes helps establish consistent equipment requirements. However, surface roughness measurements (Ra values) alone do not guarantee cleanability. Sanitary surface finish and cleanability should be considered alongside equipment geometry, installation quality, and operating conditions.
Design for effective clean-in-place performance
Clean-in-place systems allow equipment to be cleaned without extensive disassembly. Their effectiveness depends on delivering appropriate cleaning conditions throughout the equipment and product-contact surfaces.
Cleaning performance is generally influenced by four interacting factors: time, temperature, chemical action, and mechanical action. These factors must be balanced according to the soil being removed and the equipment being cleaned.
System design should support adequate cleaning solution flow and contact with relevant surfaces. Piping dimensions, pump selection, and valve configurations all influence how cleaning solutions move through the system.
Complex piping networks may require defined cleaning circuits to ensure adequate coverage. Equipment that cannot be reliably cleaned in place may require supplemental clean-out-of-place procedures. A system that supports CIP is not automatically a system that has been demonstrated to clean effectively. Cleaning performance must still be verified against established requirements.
Don’t let the wrong washdown station undercut your efforts
Washdown stations offer high-temperature steam and water cleaning systems specifically designed to sanitize your equipment while ensuring FDA compliance, improving mechanical performance and reducing facility downtime.
These systems are required for a wide variety of industries, including breweries, wineries, food processing plants, pharmaceutical facilities, and in other manufacturing and industrial settings. Our Ultimate Guide to Washdown Systems can help prepare you for a new purchase or how to optimize existing equipment.
Understand cleaning verification and validation
Cleaning verification and cleaning validation are related but distinct activities. Both contribute to confidence in a cleaning process, although their application depends on the industry and applicable quality requirements.
Cleaning verification involves confirming that a cleaning operation has met established requirements. This may include visual inspections, residue testing, or other routine checks appropriate to the process.
Cleaning validation is a documented process that demonstrates a defined cleaning procedure can consistently achieve predetermined acceptance criteria. Validation typically requires an established protocol, justified acceptance limits, appropriate sampling methods, and documented results.
Pharmaceutical operations may be subject to formal cleaning validation requirements under applicable GMP expectations. Food processing facilities may use different verification and validation approaches depending on their food safety programs and regulatory obligations. In either case, equipment that is consistently accessible, drainable, and cleanable makes the evaluation process more manageable.
Make cleaning performance measurable
Repeatable cleaning depends on the ability to control and document important cleaning parameters. Where appropriate, processing systems should provide access to measurements that help operators evaluate cleaning conditions.
Temperature and flow measurements can help confirm that cleaning solutions are circulating under the intended operating conditions. Conductivity measurements may help distinguish cleaning chemicals from rinse water or monitor solution concentration when properly calibrated for the application.
Sampling locations should be selected based on process risk and cleaning objectives. Particular attention may be needed at difficult-to-clean locations identified during system design or commissioning.
Measurement data provides useful supporting evidence, but acceptable flow, temperature, or conductivity readings alone do not establish that every product-contact surface is clean.
Build repeatability and accessibility into the original design
Cleaning consistency is easier to establish when it is treated as a design requirement from the beginning. Retrofitting an existing processing system to eliminate drainage problems or improve cleaning access can involve substantial equipment modifications.
Early collaboration between engineering, quality assurance, and maintenance teams can help identify potential cleaning challenges before equipment is installed. Reviewing proposed piping layouts and component specifications against cleaning requirements helps align system design with operational expectations.
Repeatable cleaning ultimately depends on both equipment design and a controlled cleaning process. Neither can reliably compensate for significant weaknesses in the other. Equipment should be arranged so maintenance personnel can safely access components that require routine inspection or replacement. Adequate clearance around valves and removable fittings can reduce maintenance difficulty.