Process Documentation - Critically Important
In today’s industrial process operations environment, companies are playing russian roulette if they underestimate the importance of having a well documented process. Why is it important, when you are already able to produce on-spec product? Here are just a few reasons:
- Something changes and you begin having quality issues. Such situations need to be resolved very quickly to keep customers happy and minimize the negative economic impact. Trying to troubleshoot even relatively simple processes without good process documentation can be difficult if not impossible. If you're not careful you can find yourself frantically trying one thing after another in a haphazard manner without being able to systematically analyze the process such that you can get to the root cause of the problem and correct it.
- You want to add a new production unit or make other significant changes to the plant. The engineers tasked with the design of such a project can't begin without first having an accurate understanding of the existing process (what are the composition and conditions of the streams that the new process will interface with? where are the optimal tie in points? do we have enough excess utilities to support the new process? etc.).
- There has been a spill, accident, or fire. This may put your plant under an immediate microscope from regulators. Having proper and thorough documentation of the process and procedures can be your best asset in demonstrating management competence and diligence in running the operation and trying to keep your staff safe.
PROCESS' process documentation services include:
- Process Flow Diagrams (PFDs) with Heat & Material Balance (HMB) Data
- Piping & Instrumentation Diagrams (P&IDs)
- Standard Operating Procedures (SOPs)
- Relief System Sizing Information
- Process Safety Information (PSI)
The PFD is a visual depiction of your process augmented with critical information on each stream (flow rate, temperature, pressure, composition, etc.). Working hand-in-hand with the process simulation model and the Heat & Material Balance (HMB) information (also referred to as Mass & Energy Balance - MEB), the PFD allows the engineer to look at other options that may be available to the client that may provide a more cost effective alternative to improve the process. Having an agreed upon PFD is essential before proceeding on to the development of the P&IDs for a new or modified process project. Developing a PFD with an HMB for an existing process provides a baseline for the engineer to modify and/or optimize the system. Whether it be debottlenecking, adding another unit, expanding a process, adding heat recovery, etc., having a sound PFD is critical before proceeding on to developing the P&IDs.
The PFD stream information is a result of the HMB, either using simulation software or a spreadsheet. Having a simulation model of your process that accurately reflects current operations can serve as a repository for the physical, chemical, and thermodynamic properties. Think of it as an electronic calculation sheet documenting your process. Even better is to have a simulation model that has been 'tuned' with operating data and validated through plant testing to serve as an accurate predictive tool, over some reasonable range, of what your process may do if you change operating parameters, raw materials, etc.
Whether it’s a new or existing process, having an up to date or “As Built” P&ID helps in many ways. It allows you to review the process from both the technical functionality and safety perspectives.
For existing processes, it’s critical to know what is really out in the field before proceeding with modifications. Many times, drawings are not kept up as changes are made in the plant. Everyone is busy with more pressing issues and it is easy to overlook. PROCESS often performs a unit walk down in advance of a new project so that our highly trained staff of chemical engineers correctly understands what they are dealing with before troubleshooting or designing an improved process for the client.
Furthermore, design drawing P&IDs don’t always capture all of the process details that an "As-Built" drawing will such as caps, plugs and blind flanges, etc. that may have been added during installation. The location of these can be helpful to identify tie in points for process modifications or unwanted dead legs in a food related cGMP process. Having accurate P&IDs is critical during an incident investigation or PHA to help ensure the process is correctly evaluated so as to enable identification of issues that may represent potential risks.
PROCESS provides efficient and cost effective P&ID walkdown/updating services by utilizing skilled Process Engineers and/or Engineering Technicians who are very familiar with plant process piping and instrumentation systems. The red-lined P&IDs are then checked by a process engineer assigned to the project both before and after the corrections are made in AutoCAD. This method helps ensure both quality and cost effective value for our clients.
High fidelity P&IDs that are kept up to date can also be of great benefit to plant maintenance personnel when troubleshooting, or planning preventive maintenance or turnaround work.
Project Examples Involving P&ID Development
How many times have you seen the secret stash of process settings a particular operator likes to use, or perhaps handwritten drawings for particular manifold settings when performing tank transfers or blending operations? Having a clear detailed set of procedures that have been carefully written, reviewed, and agreed upon by both operators and engineers can greatly help improve operation quality, consistency, and safety. In addition, SOPs are a great aide in training new personnel on the proper way to operate the process and will further help train the next generation of operators while minimizing errors.
To keep your process adequately protected against over pressure events, relief valve and vent header sizing needs to be re-checked when changes are made to certain process components and piping. Any changes made to piping systems where relief devices are used could cause the device to be over/undersized for its application. If relief devices feed into a common blowdown or flare header system then the sizing of the header lines and flaring devices also needs to be checked after significant process modifications are made. It is also common to find such systems 'undersized' as a result of many smaller changes to the process that have occurred over time and had a cumulative effect on the header loading.
Project Examples Involving Relief System Sizing
If your plant or process falls under the requirements of OSHA's Process Safety Management program (29 CFR 1910.119), then certain process information is required to be accurately documented and kept up-to-date.
- Heat & Material Balance information
- Piping & Instrumentation Diagrams
- Maximum Intended Inventory
- Safe Operating Limits
- Initial PHA and Revalidation PHAs (every 5 years)
- Cause and Effect Diagrams
- Interlock/Safety Instrumented Systems (SIS) Testing Documents
- EPA-RMP Offsite Consequence Analysis.
Project Examples Involving PSM Program Process Safety Information Development
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