September 24, 2013
Welding inspectors in some small, mostly rural areas don’t lack for exciting, challenging work. Their inspections often are just as critical as those in more congested, urban areas.
An American Welding Society-certified welding inspector (CWI) can expect to encounter much versatility when working in a small, mostly rural area like the state of West Virginia. A CWI in West Virginia first must inform most out-of-state customers that his state is not the western corner of Virginia. It is a realstate that even has its own flag!
I’ll admit I’m biased, but it also has the most beautiful capitol building (Figure 1) in the U.S. Thanks to former Gov.Arch Moore, its gold dome is real gold. It was plated via donations from citizens, not tax dollars. So much for the political hoopla!
Most of the work our inspectors perform for out-of-state customers actually is done in West Virginia. Contractors and manufacturers from as far away as Florida and Canada hire shops here to do their work when their customers are located nearby. It is more feasible to have the equipment built here than to build it in their shops and ship it here. This is partially due to the wage structure in our nonunion shops. Figure 2 shows a very large scrubber project for an Indiana power plant that was built in our state.
Some mining equipment manufacturers hire independent inspectors to oversee the repairs and alterations on their equipment. Because of slower sales in the coal-fired power plants and the mining industry, most producers have cut back on employing full-time inspectors. They tell us that it is much more cost-effective to use independent inspectors; they don’t have to worry about insurance, retirement, and worker’s compensation with the independents.
CWIs are in short supply in our area. The oil and gas industry has gobbled up several inspectors and nondestructive testing technicians because the pay in this industry is far above what small contractors and fab shops can pay. An inspector must check high-pressure equipment in the shop and then witness the hydrostatic test after assembly. (Note the extra safety retainers painted yellow in Figure 3.)
Much of our work is performed in areas that are difficult to access by ordinary transportation, and in the past few years, much has focused on cellular phone towers. These towers usually are placed on the highest peaks in the area. Often they can’t be seen from below, because they are higher than the clouds (Figure 4).
The part of the tower that extends high into the sky is fabricated before it’s erected, and its welds are inspected in the out-of-state shops that build these structures. The parts that we inspect are the anchors at the base and on the outer perimeter where the cables are connected to the parts that are anchored into the concrete. Thankfully, no climbing is involved.
Most of the welds are fillet and flare groove welds (Figure 5) that attach stiffener plates to the cable retainers. These welds are made with the components in place, which requires welding in all positions. There can be no defects because the welds are supporting 300- to 400-foot towers that have to withstand very strong winds that are common on mountaintops.
Inspectors’ vehicles must be capable of reaching some of the highest mountains on temporary roads for cell tower and drill rig access. The surface for the cell towers usually is a shallow layer of limestone aggregate.
Temporary roads for drill rigs, which almost always are on high mountains, usually have large aggregate, too large for a vehicle with small wheels. Our CWI group has two Pontiac Vibe®s—one two-wheel drive for traveling longer distances and one all-wheel drive for the tougher terrain. In bad weather and when the going really gets rough, we use our old stand-by, a four-wheel-drive Ford workhorse truck (Figure 6).
Much of the fab shop inspection that we relied on for years has gone by the wayside. There were a number of shops that provided parts and equipment to coal-fired power plants here and throughout the American Electric Power (AEP) system. Because of expanded EPA regulations, we have lost five coal-fired plants that these shops depended on. These shops also built and repaired coal handling and cleaning equipment. Several of them have closed or converted to pipe shops.
Most of the pipe shops have their own in-house inspectors. I recently learned that a person may be certified as a pipe welding inspector by an entity in Burton Texas—the National Welding Inspection School. I received a resume from someone identifying himself as a “certified pipeline welding inspector” (CPWI). The certification doesn’t seem to be linked to any major code or standard, such as API, ASME, or AWS, but he does have a registration number listed. This person has worked for a very prominent gas company in the northern part of our state, so it must not be a bogus certification. In general, the pipe welds require radiography, which is not something we do.
One of our most common job requests is for thickness testing. Several large municipal water tanks in our area are aging. I find it difficult to believe that a 50,000-gallon water tank (Figure 7) is fabricated from ¼-in. material.
I recently tested the thickness on one of these tanks that originally was ¼ in. and now is 3/32 in. in several places near the bottom. This particular tank is on flat ground, but some of these aging structures are on steep hills above housing developments. They should be checked for public safety at least annually. If one should rupture, it could wipe out half of a small town.
We are not a code state, but several area companies are aware that deteriorating air compressor receiver vessels could cause catastrophic events. This is particularly true in the case of an automobile service station where people could be harmed.
The very lowest part of the receiver usually has some residual water from the condensation produced by the heat of the compressor. This causes corrosion and thinning in the receiver vessel. Quite a few of these compressors produce up to 250 pounds per square inch of internal pressure in the receiver. A “corrosion allowance” is stamped on an air receiver that has been produced by a “code” shop. If the thickness is less than the wall thickness, minus the corrosion allowance, it no longer meets the ASME or National Board of Boiler and Pressure Vessel Inspectors’ requirements. I always “red-tag” these vessels, even though I don’t have the authority to shut them down. In most cases, the owner is responsible and caring enough to accept my suggestion that the vessel be taken out of service.
One of the most frightening inspections that we do is on tramways in our state parks. These cable cars typically travel 500 to 600 feet above water or earth, and a malfunction could be catastrophic.
Mounting brackets for the cable cars must be inspected by ultrasound. The bolting is inspected by magnetic particle or penetrant. Anyone who has used either of these methods on threaded material is aware of the possibility for nonrelevant indications and also for the possibility for missing a flaw—which is much worse than calling out a nonrelevant indication.
Buildings can be difficult to inspect if a conflict exists between a local erector and an out-of-state engineering firm. We had one extremely troubling experience with a parking building in our area. The engineering firm specified a weld on a stainless steel pin to be made with a low-hydrogen electrode. The erector did as told, and more than 700 of the welds were rejected. The engineering firm stated that the weld was to be entirely submerged in concrete, and that cracks and craters would not matter. The two companies put us in the middle of the controversy. The engineering firm declared that the erector used improper welding techniques, and the erector stated that the welding material was not correct.
We were called in to analyze the cause of all the failures. In our opinion, the electrode used should have been E309 or E309L. On the other hand, we discovered that the erector did not use proper storage and handling methods for the low-hydrogen electrodes that were used. Before the case went to court, I made the decision to say that “we rejected the welds, and we were not obligated to determine the cause for the failure” (even though we knew). A third party was called in, and they agreed that we were not responsible for determining the cause of the failure, but to discover and report the failures. Before the case was completed in court, one floor of the garage collapsed and the judge ruled in favor of the erector. The owner of the building finally paid us and apologized for holding up the pay.
Our CWI group is a small company in a small, mostly rural state, but we still have many exciting and interesting things to do in the inspection business. To us, our state truly is “Almost Heaven,” “Wild and Wonderful,” and “Some Place Special” (Figure 8).