Liquid Penetrant Testing Services in Tampa

Liquid penetrant testing in Tampa: acid-plant alloys, stainless pipe welds and Florida heat

In Tampa, liquid penetrant testing is used mostly on non-magnetic material. That means stainless and alloy welds and castings at the fertilizer and acid plants south of the city, stainless pipe welds in ship repair, and machined or cast parts that come off line during outages. Atlantis sends PT technicians to the site, quotes each scope on its own, and has an ASNT NDT Level III review the procedures.

Fertilizer and acid plants. Mosaic's Riverview plant has made phosphate fertilizer since 1924. It runs three sulfuric acid plants and a two-train phosphoric acid plant, alongside molten sulfur storage and an auxiliary steam boiler. Magnetic particle testing does not work on austenitic stainless or most nickel alloys and is unreliable on duplex. So in this kind of service, penetrant is the surface method for alloy welds, pump casings and valve bodies. Carbon steel items such as sulfur tanks and boiler parts are better examined by magnetic particle testing in Tampa. On alloy repairs, run penetrant alongside positive material identification to confirm that the correct alloy was used.

Ship repair. Gulf Marine Repair, on the Ybor Channel, lists 6GR stainless steel pipe welding among its welder qualifications. The vessels it repairs include articulated tug-barge units that carry liquid bulk chemicals and petroleum. Stainless cargo and service piping on vessels like these is routine penetrant work: root and cap checks on new welds, and confirmation that a crack has been fully ground out before a repair weld goes in.

Heat, rain and salt. Florida conditions change how penetrant work is done:

• Temperature. ASME Section V Article 6 sets a standard examination temperature range of 40 to 125°F (5 to 52°C). Sun-exposed steel on a Tampa summer afternoon can be hotter than that. Outdoor work is then either scheduled for cooler hours or done to a procedure qualified for non-standard temperatures.
• Moisture. The surface must be dry before the penetrant goes on. In a summer of frequent afternoon thunderstorms, that affects how a day's work is sequenced.
• Salt. After a storm surge, salt deposits have to be cleaned off before examination.
• Penetrant materials. The same Article requires penetrant materials used on austenitic or duplex stainless and titanium to be certified for low halogen content, and those used on nickel alloys to be certified for low sulfur content.

What decides acceptance. An indication is recorded first and evaluated second, against the code that governs the item. For a pressure vessel that is ASME Section VIII, for process piping ASME B31.3, for power piping at plants such as Tampa Electric's Big Bend station ASME B31.1, and for structural steel AWS D1.1. A rounded indication that is acceptable on a vessel weld may be rejectable under another code, so name the acceptance document in the request.

Next steps. Penetrant testing services sets out the national scope. Conventional NDT lists the other surface and volumetric methods that are often bought alongside PT. Teams building their own PT skills can use PT Level II training and the penetrant testing simulator. Request penetrant testing in Tampa with the material, part list, surface condition and access dates.