Passivation and Corrosion Contractor in Arizona

Yes, across Phoenix, Tucson, Chandler and statewide, on process equipment, water treatment and recovery plant. Work is to ASTM A967 with cleaning per ASTM A380, and the record carries measured values. On recovery trains we establish the concentration factor at each position before recommending anything.

Because recovery concentrates everything it does not remove. Feed water with modest chloride becomes a reject stream with chloride at many times that level, and chloride is the specific agent that breaks down the passive film on austenitic stainless and initiates pitting. The higher the recovery rate, the more concentrated the residual stream.

Because they are in different duties despite being in the same system. Product water is the mildest stream in the plant and equipment there performs indefinitely. Reject handling, concentrate storage, evaporator feed and brine circuits see many times the concentration, and if everything was specified against the feed analysis, only that end is under-specified.

By position in the train, against the water each item actually sees, with the concentration factor calculated during design. A single specification across a recovery system is either wrong at the concentrated end or over-specified at the clean end. Expect the answer to change along the train; that is a normal outcome, not a design failure.

Yes. Chloride attack becomes more aggressive as temperature rises, so anything combining a concentrated stream with heat sits at the hardest point in the system. Evaporative stages are the clearest example and deserve the most attention in both material selection and inspection.

It will give a correctly selected material the best surface it can form, which genuinely helps. It cannot change the alloy. If the installed grade is unsuited to the concentration at that position, passivation improves the surface of an unsuitable material and the pitting returns. In that case the answer is replacement at the concentrated end.

By position and pattern. Free iron contamination shows as scattered rust spotting anywhere in the plant and responds permanently to cleaning and passivation. Chloride pitting concentrated specifically at the high-concentration end, and returning after treatment, is a material selection message rather than a surface condition one.

Necessarily, yes, and it should be part of the decision. Pushing recovery higher concentrates the residual stream further, so a scheme that raises recovery without revisiting materials at the concentrated end is creating a corrosion problem as a by-product of a water saving. Both belong in the same analysis.

Barely. At 7.90 cents per kilowatt-hour against a national average of 8.13 (EIA, 2024), heating a treatment solution is a few hundred dollars. The cost that matters is downtime on a water system the plant depends on, which is why this work is normally sequenced around planned outages rather than run reactively.

Use the form on this page or call 201-450-8280. Useful inputs are where in the system the corrosion appears, your recovery rate and the concentration factor at that point if known, a feed water analysis, the installed materials, and whether the attack has returned after previous treatment. Photographs and position together are usually diagnostic.

Antiscalants are largely benign, but oxidising biocides such as chlorine and bromine attack stainless in the concentrated reject, and dechlorination ahead of the membranes has to be complete for the membranes and for the downstream metal. Treatment chemistry is reviewed for the metal as well as for the membranes.

Fibreglass pressure vessels for the membranes themselves, with stainless or duplex for the manifolds and headers on the concentrate side, and thermoplastics where pressure allows. The vessels avoid the corrosion question; the manifolds between them do not.

In duplex or super duplex for high-pressure concentrate pumps and valves, with seals and trims chosen for the chloride level, and with thermoplastic or lined components where pressure permits. Pumps see the concentrate at velocity and temperature, and they fail before the pipe.

Cooling towers running at high cycles concentrate chloride and sulfate, and the warm, aerated basin water attacks stainless at welds and crevices in the basin, piping and heat exchangers. Tower water is a recovery-style concentrate at lower pressure.

A short interval on the concentrate end, set from the observed pitting rate, with pit depth measurement at known locations, and a longer interval on the feed end, because the corrosion rate rises along the train. The interval is not uniform, and the concentrate end sets it.

A figure calculated from chromium, molybdenum and nitrogen content that ranks alloys for chloride pitting resistance. It is used to compare candidate alloys against the chloride and temperature of the duty, and to explain why 316 fails where a duplex survives.

Oxygen sustains the cathodic reaction that drives pitting, and the reject in an open or aerated system carries it, so deaerated or closed sections corrode more slowly than open tanks and vented lines at the same chloride level. Oxygen is one of the variables, alongside chloride and temperature.

Section by section, with the alloy of each section confirmed and the chemistry matched, and with the treatment following cleaning that removes scale and biofilm. Passivation on a scaled surface treats the scale.

Scale deposits create crevices under which chloride concentrates and the surface cannot repassivate, so scaled equipment pits under the scale. Descaling and passivation are done together, and scale control is part of corrosion control.

With coupons and probes in the concentrate streams, inspection of the highest-risk locations at intervals, and tracking of concentrate chemistry. Monitoring shows whether the materials are keeping up with the recovery rate.

Yes, wherever water is reused to high recovery. The product is irrelevant; the concentrate chemistry is what attacks the equipment.

Arizona's dry climate is mild on external surfaces compared with coastal states, so atmospheric corrosion is a smaller concern. The internal duty in the recovery train is the problem.

Thermal concentrators see the most concentrated chloride in the plant at the highest temperature, so they are built in titanium, high-nickel alloys or duplex depending on the brine, and inspected on a short interval. They are the end of the recovery train and its most demanding equipment.

For tanks and some piping, linings and coatings are effective where temperature and mechanical exposure allow. Heat exchangers and pumps generally need the right alloy.

Analyse the concentrate at the point of failure and compare it with what the alloy can resist. That comparison tells the plant whether it has a passivation job or a materials job, and they cost very different amounts.

Citric is usually the better fit on a recovery train. It chelates the metal ions a concentrated reuse stream leaves behind as well as removing free iron, and its spent solution neutralises to a discharge the plant can handle. Nitric passivation to ASTM A967 works chemically, and in a water-constrained state the rinse volume and the disposal route are what decide it.

The chemical stage uses comparable volume. The difference is the rinse: nitric needs rinsing to a low residual and its effluent needs more neutralising capacity, while citric neutralises more simply. On an Arizona site where rinse water is metered and the concentrate has nowhere cheap to go, that difference is a real number.