When considering optimizing your capital projects, it is important to select a contractor who can deliver the most benefits for your project's specific needs. One such benefit is the contractor’s ability to provide both in-field and shop fabrication services. The ability to provide fabrication services in both settings can be a tremendous advantage for streamlined project execution. Understanding fabrication in construction and the elements of different fabrication processes is important when researching potential contractors.
What is Fabrication in Construction?
Fabrication in construction is the process of taking an engineered drawing or design, then taking the specifications and requirements from each client and being able to assemble a finished product that meets the client’s requirements. Contractors complete this at either the project site/facility or in a shop off-site managed by the contractor. With strategic planning and cross-department communication, the construction team may complete the construction of various project components while work packages are still in the engineering and design or fabrication phase of the project. The remaining construction activities required to meet predetermined deadlines and goals per the scope of the project—including all civil, structural, piping, equipment, electrical, and instrumentation activities—will then take place during the construction phase.
Shop Fabrication vs. Field Fabrication
The difference between shop fabrication and field fabrication is that shop fabrication is completed within an in-house facility, while field fabrication is completed on-site at a project facility. Despite being called fabrication shops, these shops don’t just work in fabrication and assembly. Fabrication shops also focus on procurement aspects of the project by ensuring all materials arrive on time and are properly handled from the time they enter the shop to the time they install them in the field. Procurement plays a significant role in sourcing components that meet the authorized materials list (AML) requirements and the schedule for proper execution.
Due to the vast differences in each project's requirements, each project will need to utilize different techniques. Understanding the benefits and setbacks of each (shop fabrication and field fabrication) can help you determine whether your project needs shop fabrication, field fabrication, or a combination of the two. Your selected contractor should be able to support your capital projects' fabrication needs, and their capabilities must be vetted and evaluated
No matter where fabrication is completed, shop or field, it is imperative to keep safety a primary concern. Shop fabrication can provide more safety measures than in-field fabrication because the environment is controlled. When in the field, areas are often congested with other things happening simultaneously, so construction teams MUST do everything possible to keep safety as the number one priority.
If the EPC contractor has shop fabrication capabilities, many project components may be pre-fabricated or pre-assembled off-site in the fabrication shop and later installed at the facility. Working in a controlled environment, like during shop fabrication, can help reduce the amount of downtime that can arise due to things such as weather and permitting and help save on-site space that may be necessary for other parts of the project.
Not all EPC contractors have in-house fabrication capabilities. However, working with an EPC contractor who can perform fabrication in-house helps maintain the cohesive workflow and communication stream and provides greater schedule certainty.
For less-complex fabrication projects that require a repeated function, field fabrication can be beneficial. For example, straight-run piping is typically better performed in the field because there is very little complexity, and you can quickly mobilize from one weld station to the next weld station, repeating the process.
Field fabrication requires more manpower and resources than shop fabrication does. Shop fabrication produces products that are completely ready to install, therefore optimizing the amount of productivity in a standard workday.
For projects that do not have high accuracy to an engineering tie-in point, it’s more beneficial to have field fabrication. This way, they can take measurements in the field with fewer discrepancies.
With the use of 3D laser scanning, you can achieve high accuracy rates for your shop fabrication by identifying measurements to provide a seamless installation.
H+M Industrial Provides Both Shop Fabrication and Field Fabrication
Types of Fabrication Services
Some fabrication services are more common than others. These are common fabrication services in order of most common to least common.
- Pipe Fabrication and Testing: The testing of fabricated pipes—mechanical piping fabrication being the most common. This may include hydrostatic testing, magnetic particle inspection, Charpy impact testing, and ultrasonic testing.
- Vessel Fabrication - ASME U Stamp: The ASME U Stamp indicates that the pressure vessel adheres to all ASME design, fabrication, inspection, and testing guidelines. It is utilized for certification and acceptance of pressure vessels.
- Structural Support Fabrication: The assembling of materials and equipment necessary to help with the firm anatomy of a project.
Selecting Different Materials
Determining what kind of material to use for your products is an essential step in the fabrication process. The type of materials used is highly dependent on the scope of work and the facility's needs. An important distinction to make is: What kind of erosion and temperature will you expect it to withstand?
For pipes that are holding acids, you can expect high erosion. This will require materials stemming from stainless steel to specialty alloys. Carbon steel would be the best option for normal surfaces or standard temperature ranges. High-tension strength stainless steel can be utilized for withstanding extremely low temperatures.
Necessities For Different Fabrication Processes
- Ensure all components go through the procurement process and are all approved for constructability purposes. It’s important to approve the ID matches based on the piping specifications and the AML for necessary materials.
- It’s essential to review the isometrics with construction managers to identify the best locations for them to perform field welds. Then, by taking isometrics and converting them into spool sheets based on the specifications given for construction, you can identify that all the components meet the requirements.
- Heat numbers must be recorded before every fitting and documented in the shop traveler. Fabrication is based upon those spool sheets that are generated to make sure the dimensions and material specifications have all met the criteria.
- Whether it be radiographic (RT), dye penetrant (PT), magnetic particle (MT), or ultrasonic (UT), the non-destructive examination process (NDE) is required. The specifications are based on the client's requirements for the inspection purposes of that specific line.
Tracking System in Fabrication
Tracking systems are extremely important for procurement and fabrication in construction. Contractors set up multiple control points to utilize the barcode scanner. Using a barcode scanning tracking system, contractors can send reports to clients at any given time to locate specific destinations of an individual spool and to report what stage of completion the project is currently in. This tracking system is utilized for both shop fabrication and field usage. If a revision comes out through engineering for something that’s already started, contractors can use the barcode system and track that individual spool to its current stage, place it on hold, and remove it from the workflow before any further time or energy is wasted, resulting in lost revenue.
Contractors can take the revised sheet, identify all the modifications that must be made, and then reissue it back into fabrication.
If the field has a spool they are missing or having concerns with, they’re able to get that number and have all the dates recorded from:
- When the materials were issued
- When the pipe was cut
- When the fabrication was complete
- When the welding was complete
- The day it went through NDE
- The day it shipped from the shop to paint or final destination
Barcodes can easily ‘transform’ from paint to the field whenever they come out of the laydown yards and are issued for installation.
Why is Fabrication in Construction Necessary for Capital Projects?
Fabrication in construction can optimize your capital projects by increasing the production capacity and facilitating timely project execution. Capital projects are dependent on cost, schedule, execution, availability of resources and materials, and qualified craft.
With shop fabrication specifically, if an immediate need arises, it can be taken care of quickly since there are materials and space to facilitate the issue. Shop fabrication also gives owners and operators an upper hand on their projects because of all the in-house coordination put into ordering and shipping materials.
When looking to execute a capital project, it’s important to consider the levels of fabrication that will be necessary. Shop fabrication and field fabrication are beneficial for different project specifications, but despite the one you go with, it’s necessary to have some aspect of fabrication available. Verify that your contractor at least has shop fabrication abilities.
H+M Industrial: The Best Contractor With Shop Fabrication
Fabrication in construction is vital for the optimization of capital projects. Field and shop fabrication both have benefits and drawbacks, depending on the specifications of your project's scope. Guaranteeing that your contractor has fabrication capabilities is important for optimization as well. With H+M Industrial and our years of experience in the field with all different sizes of projects, your capital project will prosper through each stage of the project lifecycle. Having the in-house capabilities of engineering, fabrication, and field installation all controlled under the same company allows issues to be resolved in-house together. Our top-quality equipment and large investments in fabrication have named us as one of the most trusted EPC companies in the energy and chemical industries.