Work Within The Design Limits
Work within the design limits – Once equipment or a process is allowed to run outside it’s design limits it will fail quickly. The only way to get long-lived, well operating plant and equipment is to keep its individual components working within their service limits throughout their life. Keywords: training manual, procedures, operator manual.
The best way to guarantee long equipment life and reliable operation when in service is to run and maintain plant items exactly as the item’s designer planned for it to be done.
An operator and maintainer’s duty is to know the design limits of their process equipment and keep it within the acceptable design conditions. They need to know the engineering of their equipment so that they can operate and maintain it in the right ways to keep it working as designed.
Find out how the designer wanted it done. Read the manuals and understand exactly what to do and especially why it is done that way. Make the knowledge known to everyone that uses or maintains the equipment, make sure it becomes standard operating practice and make sure that it is never forgotten by anyone. This approach will give you confidence that your plant and equipment will work properly all its life.
If necessary rewrite the manufacturer’s manuals into step by step procedures for operators to follow and step by step procedures for maintainers to follow. Use pictures and diagrams to explain what is happening in the equipment or the process. Explain in details and train people to understand what they must know to run the operation well and near to perfection.
Equipment, machinery and processes used in industrial plants and facilities are built to known, well-understood engineering principles. The process and equipment designer uses them to create equipment, machinery and processes. The designer expects that the operators and maintainers responsible to run the plant, processes and equipment operate and maintain them so that they perform exactly as he they were designed to work.
When the designer selects the materials and methods of transferring power and forces through equipment he works within the material’s design limits, chemical compatibility, thermal expansion allowances, fits and tolerances and the like. When the equipment is taken beyond the abilities of its design it is operating outside the expected duty and outside its limits of safe service. The equipment can fail at any time under those totally unwanted and unplanned conditions.
For example the designer assumes that bearings will be lubricated exactly as the bearing manufacturer states they are to be lubricated. That they will not experience forces greater than they were designed to take. Another example is that the designer expects wearing parts to be replaced when their operating life has come to an end. He has to make these assumptions to be able to build his design for a reasonable cost using the materials available.
A process, plant or equipment operator and maintainer has the job of nurturing their plant and equipment so that it operates within the service limits set by the designer. If the equipment runs outside of those limits the problem must be corrected quickly and brought back into tolerance or else it will fail and breakdown. When the plant stops too often the business will lose money, it will lose customers and eventually employees will be put out of work.
Mike Sondalini – Maintenance Engineer
We (Accendo Reliability) published this article with the kind permission of Feed Forward Publishing, a subsidiary of BIN95.com
If you found this interesting you may like the ebook Process Control Essentials.