In the first step to Zero Breakdowns, we discussed Maintaining Basic Conditions. In this blog, we will discuss maintaining operating standards. Maintaining operating standards requires determining the design capacity for a particular piece of equipment. Once this is determined, the goal is to achieve this design capacity, not to exceed it, also not to fail to reach it. Unfortunately, many companies today believe that exceeding design capacity is good. However, as design capacity is exceeded, service life and reliability of the equipment is reduced. While the speed or the instant output of the equipment may look good, the resulting downtime impacts negatively the overall capacity.
Many companies struggle to understand or find design capacity for their equipment. However, there are many methods available. The first would be to consult the manufacturer. The manufacturer should be able to provide design capacity documentation for the equipment. Another option would be to find a similar use customer who knows the design capacity of the equipment. A third option would be to consult the history records of the equipment to see what it had been able to achieve in the past and the resulting reliability of the equipment. Using these methods, a company should be able to determine the correct design capacity of the equipment.
Standardizing operating methods
In many organizations, maintenance employees can look at the production scheduling board and determine by the operator schedule what equipment will break down. Quite simply, this is because different operators will operate the equipment using various procedures. Operator variability has a definite impact equipment reliability. The solution to this problem is proper training of the operators and the development of standardized operating procedures. If the operators are trained and the procedures are followed, then it will not be difficult to have standardized operating methods. This will eliminate introducing operational variability into the equipment/ process.
When equipment is installed and operated, it must be operated in the environmental conditions that the equipment was designed to function. There should not be excessive temperature, either too hot or too cold, excessive vibration, or shock loads. The equipment should be operated as it was designed to be operated. Any variance outside the operating parameters specified by the vendor will contribute to unreliable equipment.
This also includes the storage condition for major spares or components for this equipment. Major spares should be stored in suitable conditions to prolong the life of the spare part. If sub-assemblies and spares are not stored correctly, when they are installed on the equipment they will provide less than satisfactory service, both from a reliability and a life-cycle perspective.
For example, motors, gear cases, and pumps in storage already have two of the three ingredients necessary to destroy them in storage. A bearing, not rotating, mounted under a load. The missing ingredient? Vibration. This sets up a condition called false brinelling. This condition is documented in almost every bearing handbook that was ever written. However, it is still quite simple to find major spares stored incorrectly in almost any company’s stores locations. The damaged spare, once put into service, provide a very short service life, which contributes to unnecessary downtime and maintenance costs.
When equipment is installed, the construction standards must be as specified by the manufacturer of the equipment. This means during the installation, there should be a proper foundation so that there is no undue stress placed on the component that is installed. Assemblies requiring attachment to supporting structures such as a piping, should also be installed with no strain from the supporting or attached structures. Piping strain can quickly contribute to misalignment of couplings and excessive wear on the related equipment components, such as bearings and couplings.
A brief consideration of the foundation for equipment during an installation can help highlight the problem. The foundation is designed to support the static forces of weight and stress. It must also dampen the dynamic forces of vibration and any shock loads.
When a foundation cracks, it allows contaminants to penetrate the foundation and degrade the concrete. This requires a repair to be made to the foundation. This is usually some form of grout replacement. Yet is attention given to the storage of the grout? Grout stored outside during the summer will have a hot cure. This leaves the grout cure in a thermally expanded state. When the grout cools, there are stresses that are locked in the grout. Eventually these stresses will be relieved and excessive cracking will result.
For a foundation to provide satisfactory service, the following points need to be considered:
- Proper Chemistry
- Proper water and cement ratios
- Quality of the aggregate
- Contain a low amount of entrained air
- Placement must be proper for load
- Proper temperature ranges for curing
- Proper humidity maintained during curing
- Proper time for curing – 7 uninterrupted days for most foundations
Now, if this level of detail is required just for the foundation, what about the level of detail for the rest of the installation steps? Do most companies pay attention to the detail, or is it just hook it up and get it running? It is little wonder that the equipment in many plants fails to perform to design specifications.
Electrical supplies and other utilities also need to be carefully examined when the equipment is installed. These areas tend to be a problem when equipment is moved temporarily or is moved frequently, as in some manufacturing operations. Any time equipment is moved and is expected to be utilized in operations, it must be installed correctly to obtain design capacity and the design reliability.
Elimination of contamination
As part of maintaining operating standards, equipment should be kept clean. However, this in itself is not sufficient. Once equipment is cleaned then the sources of contamination, moisture, process wastes, etc. must be eliminated. Unless this is accomplished, the equipment will not be kept properly clean and ultimately the contamination will impact the reliability of the equipment.
ZBS – Step 2 Conclusion
While many of the points mentioned in step 2 seem to be basic, most companies fail to properly execute them. This leads to unnecessary downtime, lost production, and high maintenance costs. Consider what percent of all of your equipment/ process downtime is related to improper execution in these areas. What if these conditions were properly controlled in your plant/ facility? What percent of your breakdowns would be eliminated? Add Step one and Step 2 together and over 50% are typically eliminated.
Now what about step 3? That will be addressed in our next blog.