The correct design and selection can reduce critical issues.
by Chris Johnson
February 19, 2019

True or false: All it takes to clean food or beverage process equipment is proper velocity and components with proper certification for cleaning.

False. This is a good start, but sanitation professionals know that equipment installation and proper drainage can have as significant an impact on the cleanliness of the process equipment as velocity and equipment design. Some believe that a 3-A valve or pump can be installed and no issues with cleanliness will arise. However, a 3-A certificate only means the equipment can be cleaned. It is up to the user to set the equipment up for success by installing it according to recommendations in the manual and ensuring proper drainage.

Pumps are one of the most difficult components to install properly. It is more than mounting to a base at the right height from the ground. One must consider all the jobs the pump performs, how it should function when processing product and how it should function while cleaning. Considerations should be made for the cleaning solution after the clean-in-place (CIP) process is complete. How much liquid remains after cleaning? Can it stay there? Can the front cover of the pump be removed to drain fluid without a cleanliness issue? Is there a way to flip, tilt or orientate the pump to drain properly with the process piping?

Ideally, leftover cleaning fluid does not remain in process equipment after the cleaning is complete. One option for draining pumps is to add a casing drain line. This option generally works well, but the drain line is prone to clogging if solids are present or the product is thick. Adding more controls to the system can help correct this issue. During the CIP process, the drain line can open to allow the cleaning solution to clean the drain line.

More controls and automation can be a good thing for repeatability, but the initial investment will be more than a standard pump. Ensure standards are followed on the location of the drain line and where the fluid drains. The location of the drain and proper installation are indicated in the pump manual. When selecting a valve for the casing drain, follow the same standards for selecting a valve for the process.

Proper valve installation is sometimes easier, but the challenges are slightly different. Pumps are generally installed closer to the ground due to their weight, but valves can be anywhere in the process. Walking around the plant to open up hundreds of valve bodies to drain out a cleaning solution is not a practical solution, especially if a valve is 50 feet up in the air and not easy to reach. To avoid this, consider the installation of the valve prior to ordering.

Normally, a single seat valve has a vertically installed actuator. In some cases, the actuator is installed in the horizontal orientation if properly specified. Many manufacturers of sanitary valves have different design iterations of products depending on the installation. A tangential discharge valve is a good example of this. These allow a valve to drain, with the proper pitch, when installed on its side.

The discharge of the valve is tangential to the body of the valve ensuring liquid does not pool inside of the valve. Pooling inside of older horizontally installed valves is a common issue and can be easily corrected with newer valve designs.

Once the physical system is designed for proper drainability, the controls aspect of draining is addressed. During the cleaning process, proper sequencing needs to be considered to prevent trapped liquid, open low point drains, open pump drain lines, actuate valves to clean seats and any other recommended cleaning actions from the OEM.

While designing a process, it is always a good practice to read the equipment manuals prior to purchase to make sure cleaning and drainability are properly covered. Other good resources are articles from the various regulatory bodies.

The common set of guidelines for the food industry are 3-A and European Hygienic Equipment Design Group (EHEDG). The 3-A standard is most commonly referred to as the dairy standard and has been used in the U.S. for many years. The 3-A standard has made its way into many industries other than dairy, because of the cleanability of the equipment it certifies. There are many resources on the 3-A website, 3-A.org that can lead a user to the proper equipment.

The EHEDG guidelines serve a similar role as 3-A. The biggest difference between the two is that 3-A is based on the design of the equipment and EHEDG has a test associated with the approval of the equipment. Many manufacturers have decided to carry both 3-A and EHEDG to cover the various markets. The website for EHEDG is ehedg.org and also has resources available for process design.

If minimizing areas for fluids to pool is a focus, this is just a start. With the proper design and selection of equipment, drainability problems can be corrected. Doing a little research and working with the proper partners will make this a lot easier.