BOILER PROBLEMS - SlideShare

Mar 12, 2016 · Caustic embrittlement can be prevented (i) by using sodium phosphate as softening reagent, instead of sodium carbonate in external treatment of boiler water. (ii) by adding tannin or lignin to boiler water which blocks the hair cracks in the boiler walls thereby preventing infiltration of caustic soda solution into these areas. (iii) by

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Boiler Water Treatment Part 2 Internal Treatment

Boiler Water Treatment Part 2 Internal Treatment Temperature increases in furnace tubes could eventually lead to tubes becoming deformed or distorted. The two main methods of deposition control are by either carbonate or phosphate control. Methods of Chemical Dosing .

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Boiler Preparation, Start-Up and Shutdown

boiler will experience major water level control problems when started up, as the greases and oils contribute to foaming conditions. In addition, important sensing lines for instruments and gage glasses can get plugged up. In extreme cases the accumulation of debris in one area of the boiler could impede water circulation

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CHAPTER 39 BOILER WATER TREATMENT

BOILER WATER TREATMENT If phosphate salts are used to treat the boiler water, calcium will preferentially precipitate as the phosphate before pre-cipitating as the carbonate, and calcium phosphate becomes the most prominent deposit coating retards the flow of heat from the furnace gases into the boiler water. This heat resistance

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Marine Engineering: Boiler Water Testing

Dec 15, 2010 · Phosphate ppm Test (PO4) Purpose: 1.It helps to maintain a phosphate reserve in the boiler to counter any possible contamination of the boiler water by corrosive and scale forming salts. However, too much phosphate in the boiler may also contribute to foaming and priming. Procedures: 1.Take the comparator with the 10 ml cells provided.

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Chemical Treatment Requirements for Steam and Hot Water

Jun 12, 2017 · If boiler water solids concentrate or dry out on the boiler surface, trisodium phosphate does not precipitate or dry out as trisodium phosphate (Na 3 PO 4), but rather as a chemical composition of sodium hydrogen phosphate having the composition ratio of Na 2.8 H 0.2 PO 4. The molar ratio of sodium to phosphate is known as the congruent ratio.

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Water Handbook - Boiler System Failures | SUEZ

The boiler water often contains elements that become corrosive when concentrated far beyond normal values as a result of design problems. Many industrial boilers, for example, are treated in such a manner that low concentrations of caustic soda are present in the boiler water. The caustic can become corrosive to steel when the boiler water is

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Boiler Tube Failures

boiler water oxygen content and boiler operation. Leads to the breakdown of the protective magnetite on the ID surface of the boiler tube. The loss of this protective scale exposes tube to corrosion. The locations of attachments and external weldments, such as buckstay attachments, seal plates and scallop bars, are most susceptible. The problem

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Boiler Fundamentals and Best Practices

Internal furnace or fire box as the 1st pass Dry back or wet back design solids in boiler water Blowdown - Removes boiler water with a high concentration of solids which is replaced by feedwater containing a low Phosphate/Polymer Treatment Characteristics

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Finding the Root Cause of Boiler Tube Failures

Symptoms: Aggressive localized boiler tube corrosion and loss of tube wall.Pits can act as stress-concentration sites which can be initiation points for stress-related corrosion mechanisms. Causes: Oxygen pitting occurs with the presence of excessive oxygen in boiler water.It can occur during operation as a result of in-leakage of air at pumps, or failure in operation of preboiler water

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