Building your first ASME code vessel, start to finish

July 16, 2013
By: Professor R. Carlisle "Carl" Smith

Taking your shop to the next level might involve ASME certification. Just what does this entail? It begins with an agency.

ASME certification

One of the most exemplary achievements a fabrication shop can attain is ASME certification, which indicates a level of quality that is superior to organizations with little or no documentation to prove their work is highly regarded worldwide (Figure 1).

The first step in determining whether you want to invest in becoming an authorized ASME code shop (a term used by many in the fabrication industry instead of the more formal “authorized shop”) is to contact an Authorized Inspection Agency. This agency, which must be affiliated with an insurance company, such as Hartford Steam Boiler (HSB CT), can explain in detail, the steps required to become a code shop.

Beginning the process is expensive. Each authorization, (S, U, PP, etc.) costs around $2,500.00. If a full set is required, the code books also can be expensive. In most cases, this cost will be $3,000 to $5,000 dollars.

Authorized Inspectors

When you enter into a contract with an authorized inspection agency, you are assigned an authorized inspector (AI). At the beginning of the process, the AI’s supervisor (AIS) explains the duties and responsibilities of the agency. Charges for the AI and AIS are invoiced once the contract is in place.

There was a time when AIs were intimidating, and rightly so. Some earlier AIs were very strong-voiced when giving instructions. Most of them were former U.S. Navy steam mechanics and had to have strong voices to be heard. AIs now are gentle and professional when giving instructions.

Joint Review

The National Board of Pressure Vessel Inspectors plays an intricate part in the overall code process (Figure 2). AIs must have a National Board endorsement, which requires a very comprehensive test that usually is administered by the state National Board or ASME representative. The organization provides guidance for preparing a quality manual that serves as a roadmap for quality code activity. This organization also is the standard for repairs and alterations to pressure vessels and piping assemblies.

Once an application for ASME authorization is submitted, the National Board of Pressure Vessel Inspectors must be informed to comply with the rules for a “joint review,” which consists of an ASME representative, a National Board representative, the AI’s representative, and the applicant’s quality representative, along with a management representative for the client.

A much more thorough description of the review and pre-review can be obtained from the Hartford Steam Boiler authorized inspection agency. This information can be obtained from other Authorized Inspection Agencies or ASME, but in my experience, HSBCT has the best.

When I say “your very first ASME code vessel,” I am referring to a demonstration vessel that must be built to the same quality standards required for any ASME code vessel. The difference is that the demonstration vessel is not completed. The AI specifies the exact work you are to perform on the vessel—typically, one head, the main body, and two fittings.

In most cases the drawing (Figure 3), the fit-up and tack, and partial welding are executed to show the review team that the shop is capable of building high quality vessels. The welding usually consists of tack welds, a partial root bead (to prove that the candidate has the ability to perform a complete penetration weld), and a completed “cap” or “cover pass.”

National Board of Pressure Vessel Inspectors

Figure 2

The documentation for the demo vessel is considered as critical as the documentation for a “real code” vessel.

A Typical Scenario

Willie the sales person (not Willie Lowman) calls on a longtime customer and is proud to say, “We now are going to be an ASME code shop.” The customer has had success with Willie’s company in the past, so he decides to give them a shot at an air tank. Willie takes the drawing and specifications back to the estimating manager for a quotation.

Jeff, the estimating manager, is extremely cautious when undertaking a new and different product. After reviewing the drawing and specifications, he decides to contact the AI. He realizes that he will be charged a half-day cost by the AI, but decides it is worth it. The AI gives Jeff the estimated charges for authorized inspections and also designates the “hold- points”—points at which to stop work until the in-process work is inspected and approved. The number of hold points in part determine the cost of the AI coming to the shop. The AI also marks the spots for radiography. This helps Jeff calculate the estimated cost for RT.  The AI and Jeff document their discussion for future reference.

Jeff requests calculations from the engineering department to ensure that the material thickness, type, and vessel design meet the maximum allowable working pressure, temperature, and other requirements. These calculations will be double checked by the AI.

The next step for Jeff is to call in Carl, the metallurgist, to check for any special concerns about the material, such as lead time for purchasing and lamination probability. Carl tells Jeff to be sure to requisition SA106 Grade B “seamless” pipe for the shell. Some pipe is dual certified, and SA53 Grade B “seam welded” (ERW) sometimes is certified along with SA106, which can be a problem when the specification calls for SA106 Grade B “seamless.”

Carl explains to Jeff that all material must be ordered as ASME code material; meaning that rather than the ASTM designation “A105,” the designation must be “SA105” for the head material. The same holds true for ordering the welding material. The AWS specification for the classification ER70S-2 is “A5.18.” For ASME it must be stated as SFA5.18. The classification is the same for both AWS and ASME.

It is very important that Jeff places the correct terminology on the requisition and reviews it with Carl, quality, and engineering before sending it to Emmett, the purchasing director, for purchasing. All the purchase order forms are marked “Material Test Reports (MTR) Must Accompany Delivery”. Such marking minimizes the possibility for error in documentation for purchasing and receiving the correct material.

Emmett sends out requests for quotes (RFQ) for the material and sends the results to Jeff for use in his estimating documentation. In the meantime, Jeff confers with Shop Foreman John and Welding Foreman Sid about the labor and with Quality Inspector Wayne about the in-house shop inspection time. This is a “sit down” and pay attention meeting! This is a critical point in which one small omission can cost most or all of the potential profit. Every minute item must be discussed at this meeting, and nothing can be overlooked. Among the items to be covered is postweld heat treatment (PWHT), which can cost more than the material for the job

Documentation requirements must be defined and clarified at this time, and the importance of marking the material must be addressed (Figure 4).

This also is the time to discuss and demonstrate the hydrostatic test procedure and determine its location. Make sure you have sufficient air and water for the test and a floor drain nearby. Moving the job around unnecessarily can elevate the cost.

Gauges are to be checked for calibration. They shall not have a range of less than one and one half times the test pressure, nor more than four times the test pressure.

All these seemingly small details can add to the cost and affect the estimate to the customer.

Assuming that all possible costs have been explored and the company is able to meet the requirement of the specifications, Jeff prepares the estimate and gives it to Willie to present to the customer.

The customer accepts the estimate and issues a purchase order. The purchase order is checked by Jeff and engineering to make sure that no unknown revisions have been made. Engineering creates a bill of material according to the drawing. At this point a “shop traveler” that lists the  AI’s hold points is prepared. This document travels throughout the fabrication process and each step is signed off by the company’s quality representative and the AI.

Emmett orders the material using the “bill of material” that was created by engineering and checked by engineering, quality, Carl, and Jeff. If Emmett encounters a problem in acquiring any of the material, he must not purchase substitute material without going back through engineering, quality, Carl, and Jeff. Along with the statement that an MTR must accompany delivery, an additional comment is placed on the purchase order to state that the fittings must be accompanied by a “Certificate of Compliance” if no “MTR” is available. Also, Emmett requests an acknowledgement for the receipt of the PO.

A copy of the bill of material is provided to the receiving inspector for checking the packing list and manifest (receiving documents from vendors) against the bill of material. This information is recorded on the receiving checklist (Figure 5). All the material pertaining to this job is kept in a designated area marked ASME Job #06-2013 material only, which allows inspectors and shop personnel to better track the job. The receiving checklist is very specific with details about each piece of material and the markings. The heat number must be marked on all parts except the fittings. Figure 4 is an example of proper marking. Markings portray the heat number, the producer (mill), material type, job number, processed by (who cut the material), and the weight.

A shop I worked for once made the mistake of blasting the shell after the marking and failed to write the information on paper to be marked after blasting. Luckily, one of our engineers was camera happy and had all the info on his camera.

It is easy to see that the paperwork is more time-consuming—requires more man hours—than building the very small vessel. Once all the parts are accounted for, the fitter/tacker, who must be ASME-certified, assembles the vessel and tacks it together. The shop inspector inspects the tacks for craters or cracks and contacts the AI to see if the fit-up needs to be inspected before welding. Since fit-up was listed as a “hold point,” the AI comes to the shop and inspects it.

To save our company money, the AI agreed to stay and go through the paper work—welding procedures, welder certifications, bill of material, receiving inspection—while the welding was being performed.

The AI makes one more visit to the shop to inspect the welding, witness the hydro test, and witness the stamping. All that remains after this visit is the final paperwork.

The data report (Figure 6) and shop traveler are to be completed and signed off by the AI and the company quality representative. The data report then is sent to the National Board for registration. All documentation is then filed away in the “master job file log” (Figure 7) and kept securely for the amount of time specified in the quality manual. This initial effort may not have realized a profit, but lookout for profits next time!

Professor R. Carlisle

Professor R. Carlisle "Carl" Smith

Weld Inspection & Consulting
PO Box 841
St. Albans, WV 25177
Phone: 304-549-5606