Pumps that exceed expectations

Customer focus creates reliability is the result of a carefully planned process, not the result of luck

Pump manufacturers design pumps not only to run smoother, longer, and more dependably, but also to minimize cost and downtime requiring unscheduled maintenance. These attributes are a function of reliability that is the ability of a device to operate correctly over a period of time. Defects, latent or existent, cause devices to fail. Pump manufacturers use many methods to reduce these types of errors.

The real answer to improving pump reliability begins with the manufacturer's engineering and marketing capabilities. It includes the ability to implement processing and quality improvements. Manufacturers continuously improve quality, cost, and delivery to satisfy customer needs. A number of changes in manufacturing philosophies directly impact the methods employed to accomplish this goal.

Engineering
Engineering significantly impacts the reliability of pumps. Computer-aided design enables engineers to examine energy aspect of the pump. Individual component design is verified by sub-programs using geometric dimensioning and tolerance rules. Tolerance analysis tools let them to verify that the components are correctly dimensioned. Parts can be assembled in the computer creating a virtual prototype with a 3-D representation. The engineer can see their creation without leaving the electronic drawing board. Finite element analysis enables the engineer to apply structural and thermal loads to determine problem points during the design stages. Virtual testing is completed before the component leaves the design stage.

Rapid prototyping allows physical models to be created in hours when it used to take weeks through traditional model shops. The computer aided design files are downloaded to manufacturing entities for sample and mold creation for castings. Samples are available for verification of engineering specifications, field testing, and assembly fixturing. The same files are downloaded to quality assurance personnel and to program coordinate measurement machines that verify dimensional adherence and aid in process control. Laboratory testing confirms hydraulic characteristics of units and accelerated life testing verifies design integrity. The design process now compresses and refines the time required to ensure the reliability of the pumps and products that are designed in a matter of months rather than years.

Dynamic balancing of impellers, tighter manufacturing tolerancing of components, and more secure attachment of the impeller to the shaft create greater efficiencies.

Many manufacturers are ISO 9001 certified. This third-party audit of the quality system verifies that a system that conforms to internationally recognized standards exists. It covers design, manufacturing, process control, manufacture, and shipment of the product.

Continuous improvements
Reliability of products is defined as the ability of a device to survive. The changes that occurred in the last 20 years in the area of quality are directly related to the improvements that you experience with your products. There are a number of devices to verify that components are manufactured to very tight tolerances, some down to less than one ten thousandths of an inch.

Components that you would imagine would be simple to manufacture are now surprisingly complex. A shaft is an example. Material type is specified by engineering and specification is determined by exhaustive testing that simulates the environment in which it will function. The chemical composition of the material is certified by a chemical analysis performed by the mill. New and sometimes exotic materials, including ceramics, are specified, depending on the application. Blanking operations are performed by sawing, turning, or even lasers. Typically, the next operation is turning the outer diameter. This operation is performed on lathes that are computer controlled to meet the contours and the specifications required. Tighter specifications require greater precision from the machine tools. Grinding and honing enables the tighter tolerances to be met. However, the contributory effects from the previous operations have been found to have a significant influence on the final outcome.

Cylindricity, parallelism, concentricity, and surface finishes contribute to the reliability of shafts. These require specialized instruments to define the actual measurement of the feature.

The ability to measure these attributes is greatly enhanced by computers. The data required is recorded, processed, mathematically transformed, statistically analyzed and presented to the operator for decision making. This type of analysis would have only be done periodically in the past. Computerization enables this to be performed daily, reducing variability from part to part.

The real answer to improving reliability begins with the manufacturer's engineering and marketing capabilities.

Dynamic balancing of impellers, tighter manufacturing tolerancing of components, and more secure attachment of the impeller to the shaft create greater efficiencies. They also assist in enhancing reliability. Bearing wear is reduced which leads to longer life.

Methods
The machinery and the measurement equipment alone have a significant impact on pump reliability. Fixturing, for both machining and assembly, are also designed to preclude errors and enhance reliability. They are designed to verify sizes during insertion to the fixture. Automated testing is incorporated at many stages during the process to ensure the critical features or characteristics are verified one hundred percent where warranted.

Making operations, visual checks, and correct configurations that are obvious to the operators ensure that assembly and machining errors are minimized. Manufacturing operation sheets are placed in work areas that specify how operations are to be performed along with a picture of how the assembled part should look before and after.

Technology has simplified this job through digital imaging. Digital pictures are taken of the operation and this data is transferred to a word processing system and inserted into the manufacturing operation sheets. This document can be annotated with arrows or text pointing to crucial areas of assembly, giving the operator on the floor the information of what needs to occur, plus the picture of how the assembly is supposed to look.

Statistical process control is performed on critical operations during every phase of manufacturing. Continuous monitoring of these processes ensure that not only the components are correct, but that the machine or process is under statistical control. What does this mean to the user? It means that the parts are manufactured in a repeatable manner. Less variation from part to part enables greater reliability.

Teamwork
At this point we have examined the physical components and processes that are used to build pumps. People are the most important component to building reliable products. The best designed pump in the world will still fail if the operator assembles it wrong. So the problem is, "How does the manufacturer train, communicate, instruct, and assist the people in an operation to accomplish their tasks correctly?"

The operations methods sheets place the correct information in the operator's hand, and make it visually clear through the use of pictures, but they are not the only component in the system that employs the human resource. Engineering, quality assurance, purchasing, production control, order management and several other functions have people that directly affect the production of products and the company ability to fulfill any order correctly and in a timely manner.

Virtual testing is completed before the component leaves the design stage.

Summary
Modern pump manufacturing requires a tapestry of machines, computers, processes, and people to ensure the reliability of the products that are shipped. You can see the advent of the computer explosion has shortened the amount of time to design, verify, order, manufacture, and test products. More importantly, computerization reduce errors.

Pump manufacturers have changed processes and procedures to improve reliability, customer service, and delivery of their product. This process is a never-ending job. Continuous improvement is the common thread that runs through all of these improvements. This ensures the pumps you purchase now and in the future will be more efficient and last longer.