Before anything else can happen in the design and construction of a manufacturing plant, the piping and instrumentation diagrams (P+IDs) are created, mapping out the plant’s processes. The outline includes equipment, pipes and instrumentation which diagram a plant’s operation as a schematic. Mechanical contractors rely on P+IDs for leak detection, repairs, and maintenance.
If you ever have to pull a P+ID to diagnose an issue caused from a leak or deal with the possibility of a leak occurring while you manipulated a piping system, then read on.
These drawings are used to guide the physical design of the plant. All plant design is then cross-checked against the P+ID to ensure compliance with the process design and operation of the plant. They are also used during commissioning of the newly constructed plant or for any additions and/or revamps.
If the P+IDs are not accurate, thousands and thousands of dollars and time investment are at stake. The safety of plant operations staff and local communities can also be at risk when accurate P+IDs are not rapidly accessible.
Some of the challenges of creating easy to read and easy to understand P+IDs?
The drafter should keep in mind that P+ID drawings are important documents used in the design process and plant operation throughout its lifecycle. Clarity and good drafting standards help create P+IDs that are legible and every item is clearly identified. Also, the data in the P&ID must be kept up-to-date. Valves, equipment tagsand other components must be updated when plant revisions and revamps are performed.
That’s why industry innovators are revolutionizing this practice, including:
· Creating P&IDs that can be used for PHAs (Process Hazard Analysis). Experts recommend visiting the client sites and walking down the P+ID to ensure that the data shown on the P+ID matches the field conditions. What’s the benefit here? Plants operate safely, saving lives and money.
· Creating “smart” P&IDs for projects so users can extract line lists, tie-in lists, instruments lists, equipment lists, and valve lists. What’s the benefit here? Improved accuracy in plans and faster creation of bill of materials (BOMs).
· Labeling and pipe marking with mobile thermal transfer printing systemsso contractors can access remote or hard to reach areas in a plant and identify the flow of liquids and gases.
· Identifying interconnecting pipes with line numbers, pipe size, pipe spec and insulation, if required.
The process generally works smoothly during the turnkey construction of new plants and system, but when projects include modifications and repairs to process piping installations systems, plant slowdowns and shutdowns have an enormous impact on productivity.
Contractors must be skilled in pipe fabrication and installation, routine repairs, upfits, and emergency response services. Specs inevitably change as a site comes together, but it’s a time-consuming hassle to make changes during working operations.
Some solid advice? Look for contractors and sub-contractors who perform industrial piping in accordance with ASME code standards.
To ensure a thorough examination during pipe installations, Jamie Miller, an executive project manager for GRP Mechanical Company, Inc., has his team working in pairs. The second man puts eyes on the critical points while the work is completed.
Miller’s crews use flange guards, safety shields, and Litmus paper indicators along with P+IDs in their process. Used in a variety of industries, these guards prevent harmful spray-outs and mist formation from failing pipe joints, and toxic, corrosive and dangerous liquids such as acid, oil or steam.Resembling a collar, these flange guards are wrapped around the valve and fastened with Velcro tags and cords. If valves leak, the Litmus paper changes color to serve as an alert.
Finally, Miller also uses a double block-and-bleed system for isolation and intervention to prevent product contamination when it is necessary to remove equipment from services for cleaning and repairs while the unit continues to operate.
Luke Orlando, Mackin & Little Mechanical gave his perspective on P+IDs and the role of signs and labels in communicating pipe contents, location, and direction.
“We use P+IDs all the time. When a new construction project or a renovation is set in motion, P+IDs provide the systems requested and methodology of installation for those systems which are coordinated amongst other trade work installations. Piping typically is tightly coordinated with sheet metal installation for dry side mechanical work and P+IDs allow for this coordination to occur and provide routing and system designs to co-exist, function properly, and efficiently,” said Orlando.
P+IDs are also used in the form of blue print plans and other similar detailed schematics to show system design and system interfaces with the structure as well as with other trade work. When estimating a project to prepare for a bid to procure work, Orlando uses P+IDs regularly. From the estimating of the job to actual install, P+IDs are critical to manage a project within a specified schedule, on budget, and within the constraints of local codes and jurisdictions.
Orlando uses signs, labels, valve tag lists, in the installation of major piping systems and operational materials in projects to indicate flow of water or process materials through piping, in order to show proper flow patterns in a system. He labels the piping to show the system it belongs to or is associated with. Finally, he and his team label all major equipment with signs, info stickers and valve tags. Of key importance are warnings about the dangers of phenols -- raw materials and additives for industrial purposes used in laboratory processes, chemical engineering processes, wood processing, and plastics processing.
Labeling supplies for mechanical contractors
Mechanical contractors rely on chemical-resistant and UV-resistant pipe marking supplies. Barcode labels are invaluable for tracking assets.
Heavy-duty valve tags are used at locations where workers need to clearly see pipe contents before opening a valve. Valve tags provide operating instructions, and display maintenance requirements. Available in multiple colors, valve tags provide solid backing for marking and they work well in harsh, abrasive condition.
Pre-drilled holes make it easy to display valve tags with plastic and metal ties. Color coded valves match pipe and facility markings. Using an industrial labeling system to create pipe markers and valve tags enables mechanical contractors to create custom, site-specific visual communications on-demand vs. ordering from a catalog and waiting for a shipment.
Orlando uses several different leak detection methods. For gas piping systems, he uses a “holliday” detector to check for defects amongst specialized coating (XTru Coat) on piping. He has used cathodic protection for gas piping as well. For smaller gas, hydronic, and waterlines, they go low-tech – using an old trick of soapy water, sprayed on joints while the system is under test/pressure. If a leak occurs, the soapy water will bubble. The appropriate methodology, system and materials will vary depending on the application.
In planning for a new manufacturing plant, all factors should be taken into consideration in advance of any action. The selection of a site should not be made until after all preliminary studies have been completed, include the types of buildings, general dimensions, number of stories of buildings, floor space required, provisions for expansion, accessibility for employees, transportation facilities and costs. All factors are related, and should be considered together. Mechanical contractors play a critical role in the quality, timeliness, and professional planning and installation of pipes and other components necessary for smooth manufacturing operations.