Last week, WQP, Water & Wastes Digest (W&WD), and Storm Water Solutions (SWS) editors traveled to Houston to speak with water...
The importance of quality control in the manufacturing of drinking water treatment units
In the drinking water treatment industry, a quality product and tight standards are important for many reasons. They help manufacturers save costs, educate employees and create a better product for the customer. It is important to the industry and the public that manufacturers make products that meet customer expectations. Some of the more critical quality control areas in the water industry include the acceptance of the suppliers’ products, documentation of the processes at the manufacturer’s facility, inspection and acceptance of the finished product, storage of supplies and finished products, and the handling of customer complaints and product non-conformances.
If the components that make up your final product do not meet your specifications, the finished product is never going to meet your specifications either. A thorough visual inspection of the incoming parts and the packaging of the parts should be done for every receipt. For example, it is very common for a container or package to arrive damaged or water marked. If a proper visual inspection is completed on the received materials, an investigation can be started and proper corrective actions can be taken.
Another important quality aspect of drinking water treatment units (DWTUs) and their components is the material composition of the parts. If you are having a company fabricate a part for you, make sure they are using the correct materials. If you are buying a mass-produced component, using an NSF/ANSI 60 or 61-certified component is highly recommended.
Finally, when accepting supplier parts, it is imperative to ensure that the component is durable. Durability checks can be conducted by verifying that the threads are working properly and that the thickness of the component’s walls and openings are correct, as well as running it through specified quality control tests. These are just a few quality assurance examples for components purchased from outside vendors, but remember that new improvements and methods for quality assurance should always be used in the process to ensure your QA/QC procedures are working.
Along with the inspection of incoming material, it is both educational and a sound business practice to systematically review the manufacturing processes that take place at the manufacturing facility. Detailed documentation regarding every process that goes into making a product will provide several benefits to the company.
Having all processes documented makes training new or existing employees much easier. With thoroughly documented procedures, employees can begin to learn and perform a manufacturing procedure without actually performing the task in the plant, where mistakes can slow production and waste product. Furthermore, they have the ability to review each of the steps for their specific task even if the equipment is not up and running. Another tool that can be used to ensure that all processes are documented properly and kept current is to have employees create, revise or improve each process document during quality control training exercises. Having employees do this gets them involved in quality control. This may convince the employees that quality control isn’t always a painful process, and documents can be kept more accurately by including everyone in the process. This also creates motivation for the employee, helps maintain their training and generally improves the process itself.
Finally, it is important to ensure that all manufacturing process documents are reviewed at least once per year. During this review, efficiencies and deficiencies can be identified for all operations, and improvements can be made that increase the efficiency and quality of each process.
Not only do the best DWTU companies have exemplary quality control standards and precise procedural guidelines, but they also have safe, manageable and efficient quality assurance procedures for their finished product. The inspection of the final product should verify that it meets established specifications; this is one of the most important quality checks for the company. Some good practices for final inspections include:
A system of checks and balances will help catch non-conformances. Line workers typically conduct a series of checks to ensure they have conducted their step of the process correctly. These checks are typically stored in logs that can be referenced later on. In order to balance these sets of checks, companies should ensure that a different employee spot-checks the log and products to ensure nothing was missed. If a product is being assembled, verify that the units have all the proper components. If a product is fabricated, make sure it meets dimensional and material specifications. Have multiple employees review some or all of the products for specifications.
When testing is completed on the units, maintain all the procedures and inspection logs of the completed tests along with the results of each test in an organized system. The data collection system that is put into practice must be understood by all employees. The logs that contain the final quality checks are the final barrier that ensures the quality of every product before it is shipped.
When conducting inspections, make sure a qualified person signs off on all quality checks. New employees should never be conducting final inspections unless an experienced employee is training them. A quality control officer should review all test logs at specific time intervals each day. A final check and sign-off of each quality control test should be reviewed and signed at the end of each day or shift.
It is also important to control contamination that may affect the material safety of the product. It is vital to avoid getting products contaminated in any way because of the possibility of it being harmful to the customers. The proper storage of supplies and finished products will help prevent material safety contamination of products. With the proper preplanning, execution and organization, contamination can be avoided to ensure product safety.
When planning the storage of items, consider the environment in which the product will be stored. Many components and materials can adsorb airborne organic contamination; therefore, consider the layout, location and air quality of each designated area throughout your plant and consult other water professionals should there be questions concerning storage.
It is also important to remember that the stored material or product may come in contact with process water, dust, humidity, temperature and sunlight. Therefore, each of these environmental factors and its effect on the stored material must be taken into consideration. A good place to start is to use a drawing of the facility to establish areas for storage of specific chemicals, parts and other supplies, remembering to ensure proper segregation of items that may cause contamination. Areas that will prevent damage to fragile products and supplies are also important to consider. Also, make sure you have a specific area that is solely dedicated to non-compliant material that has not passed inspection criteria.
Finally, record all customer complaints, supplier non-conformances, in-process non-conformances, and final product non-conformances—and create an area to isolate any product non- conformances. Even if a complaint seems to have little merit, it should be recorded in a complaint system. If the proper recording is done with a complaint, it may turn out that there is a recurring problem that was not discovered during the internal review process. Careful and concise recording of all complaints and non-conformances can save the company money in the long run, and can provide an excellent record you can use to hold your suppliers liable if necessary.
A final note: Please remember that if there are non-conforming materials and/or products, make sure there is a well-established area to keep them separated so they are not accidentally shipped or used in production.
Overall, the time and effort spent focusing on these critical quality control areas of the manufacturing process are worth it in both the short and long term. With ever-evolving internal and external change, you will see immediate improvements to the products and in the satisfaction of your customers. The company and ultimately the industry as a whole will benefit from increased awareness in these areas of quality.