Advanced fluid control technology increases efficiency and reliability of Clean-in-Place and Steam-in-Place systems

Emerson’s Audrey Richard explains the importance of valve design and electronic fieldbus platforms in helping pharmaceutical and life sciences companies and original equipment manufacturers optimise their clean-in-place operations.

Clean-in-place (CIP) and steam-in-place (SIP) systems are used within pharmaceutical and life sciences manufacturing to eliminate cross-contamination and ensure product quality and safety.

CIP and SIP systems provide reproducible and reliable delivery of cleaning solutions and rinse water or steam through process equipment and piping without the need for any disassembly.

The automated cleaning process minimises cleaning time and decreases downtime between batches; reduced contamination results in higher product quality and fewer recalls; and automated processes lead to fewer mistakes and increased employee safety.

In the pharmaceutical and life sciences industry, the CIP and SIP process is extremely harsh and involves multiple cycles, including an initial and final drain step, a pre-rinse, a sodium hydroxide wash, and a post-rinse. Rinse and wash cycles vary from five minutes to one hour.

The process may include a sanitise cycle to reduce the levels of bacterial contamination using strong oxidants such as hydrogen peroxide, ozone, chlorine dioxide, or other chlorine-containing compounds.

It is vital for original equipment manufacturers (OEMs) to develop CIP and SIP systems that are as fast, efficient and reliable as possible. A faster cleaning process will enable production of the next batch to begin sooner, contributing to greater production efficiency.

Reliability is also essential. Should a cleaning system fail to operate, this may delay the restart of production, while equipment issues could elongate a cleaning cycle or require a cycle to be restarted.

Products deployed in CIP and SIP systems — such as valve systems, sensors and valve islands — must be extremely robust, reliable, easy to install and integrate with the existing plant network, and offer extended lifecycles. CIP and SIP systems must also provide users with diagnostics and condition monitoring data to support predictive maintenance strategies and improved maintenance scheduling.

In addition, systems must support environmental sustainability goals, helping to minimise the amount of compressed air, water, steam and chemicals used, which will lead to greater energy efficiency and reduce costs.

Ensuring the efficacy of CIP and SIP processes requires precise measurement and control to manage the sequencing of lines and vessels for cleaning. Effective sterilisation is largely dependent on CIP and SIP processes reaching and maintaining specific temperatures.

Any deviations in temperature or inaccurate readings from faulty equipment can diminish the efficacy of these processes and lead to contamination that results in product loss. Robust temperature management technologies must therefore be deployed to ensure accurate, repeatable temperature measurements.

Fluid control technology

Cycling with cleaning media and steam creates a difficult operational environment for valves and can create problems with seal life and ensuring consistent on/off shut-off. There are also tight footprint requirements to consider, while compliance with stringent hygienic regulations is essential. Selecting appropriate fluid control technology, including valves, is essential for CIP and SIP system reliability and performance.

These devices must be able to cope with the extreme environments, and offer outstanding reliability and long service life. A valve failure or a device that does not actuate due to a pneumatic systems failure can jeopardise the entire system.

The latest valves, such as the ASCO™ Series 290 from Emerson, comply with Good Manufacturing Practice regulations relating to hygienic applications, and provide high performance and reliable and accurate control in even the most demanding environments.

That includes high-temperature fluids and steam up to 356°F (180°C). Heavy-duty PTFE sealing ensures an exceptional level of repeatable shut-off tightness, while high-grade, corrosion-resistant materials including stainless steel protect the valves from the aggressive cleaning fluids used in CIP systems.

Robust construction helps to maximise reliability and service life, and provide a high level of versatility and flexibility, enabling OEMs to minimise design and engineering complexity by selecting a single valve for different media. That is further enhanced by modular designs offering a wide range of body connections, interchangeable actuators and switchboxes.

Valves designed to require no maintenance help to maximise the availability of CIP and SIP systems, while greater equipment reliability helps to enhance the safety of both plant and personnel. An anti-water hammer design helps to prevent damage to the valve and pipework that could cause dangerous leaks impacting instrumentation critical to process control and safety.

The design of angle body valves enables high flow rates for their size, while the valves’ smaller size compared to quarter-turn valves makes them ideally suited to applications where space is at a premium, such as in CIP systems. Valves with a 360° rotatable ultra-compact actuator can be easily aligned to the connections, potentially resulting in further savings in installed space.

One of the key objectives of a CIP system is to be as energy efficient as possible, and valves can play an important role in achieving this. For example, selecting valves with low consumption of compressed air will significantly increase energy efficiency and reduce costs.

Electronic fieldbus platforms

Pneumatic systems with integrated digital communications have been available for many years. These allow programmable logic controllers or distributed control systems to more efficiently turn valves on and off and channel I/O data from sensors, lights, relays, individual valves, or other I/O devices via various industrial networks. Electronic fieldbus platforms can easily integrate communication interfaces to pneumatic valve systems with I/O capabilities.

These are plug-and-play solutions that reduce the time and cost of commissioning and installation. They simplify engineering by replacing rigid architectures with a wide range of flexible and cost-effective I/O distribution options, making the same components available for either centralised (main manifold) or distributed (sub-bus manifold) use.

Any inefficiencies in CIP and SIP system troubleshooting can lead to increased process downtime. Most fieldbus manifold designs offer diagnostic LEDs on the manifold system itself, at the point of use. However, it is not always easy to peer past tangled coils of cables and connectors at dim, diminutive LEDs. Are they on? Are they red or green? Are they blinking quickly or slowly?

Fortunately, the latest designs offer more functional alternatives such as an integrated graphical display with plain-language messaging. This provides users and OEMs with a wealth of point-of-use status and diagnostic information, plus setup and version tracking data at both the I/O-module and communication-node levels.

This arrangement places visual status and alarm indication away from tangled cables, in a clearly visible display area at one end of each module. It involves no programming or extra cost, and takes no training to use.

Error messages are generated and cleared automatically, and blink to draw the viewer’s eye immediately to the problem module. These error messages include notification that a short-circuit condition has been detected on the sub-bus power lines or on a valve coil, that a sub-bus module that had been previously installed becomes absent from the configuration, and when valve/output power is not detected. 

The display’s associated pushbuttons allow the user to navigate quickly through intuitive menus for easy and effective troubleshooting, enabling downtime to be reduced. Some systems even log errors for future or remote analysis.

Traditional fieldbus valve manifolds suffer from a fairly low degree of modularity, which presents challenges for OEMs and end users alike by requiring wholesale dismantling for changes or replacements. However, the latest platforms provide modular designs that simply connect together via easily removable clips and screws.

This allows easy assembly and effortless last-minute changes for OEMs. For end users, modularity permits quick, trouble-free field changes. I/O modules can be removed and replaced without forcing the user to dismantle the entire pneumatic fieldbus valve manifold system.