Acid Cleaning

As part of our arsenal of services, NTS to provides a variety of acid cleaning services to the aerospace industry.

Stainless Steel Pickling

Sooner or later most stainless steel ends up being welded, heat treated or subjected to some type of high temperature process. Pickling stainless steel involves the removal of the resulting scale and any adjacent low chromium layer of metal from the stainless steel surface via the use of chemicals. The damaged layer must be removed to expose the more rust resistant layer underneath.

NTS incorporates both the traditional method of pickling with solutions of nitric (HNO₃) and hydrofluoric (HF) acids and citric acid treatments to restore corrosion resistance. Where a liquid solution is impractical, such as outer layers of large welded structures, NTS field services will use acids in a paste to secure the right length of exposure at the correct place. NTS has extensive experience in pickling all components and systems, whether they can be processed at our clean room facility, or out in the field. Size is not a barrier - NTS has successfully removed rust, scale and discoloration from structures as large as a 3,000 sq. ft, two-story stainless steel chamber.

Acid Cleaning for other metals

To remove oxides, light rust and light oils, phosphoric acid can be used on most metals. Aluminum, copper, and their alloys respond well to nitric acid. For carbon steel, hydrochloric acid may be used. However, using these methods, unprotected low alloy steel will almost immediately flash rust. NTS prefers an environmentally friendly method of removing rust, weld scale, and related imperfections in carbon steels: a multi-step process involving citric acid. In systems and on parts that can be contained within a controllable environment such as a closed loop system, or a controllable chamber, NTS will in one process achieve removal of weld slag, rust and contaminants while passivating carbon steels to retard rusting. The resulting surfaces bear a resemblance to sandblasted alloy metals and are suitable for use with oxygen, some fuels, purge gases, and various other media where cleanliness and resistance to rust are important, while the reduced cost of carbon steel plays a role.

National Technical Systems chooses to employ the citric process in almost all its field applications in order to save clients' money, protect the environment, and speed up the process (due to both faster processing and easier disposal).

Contact NTS today to find out more about how to get your product serviced!

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