Definition: Write a phrase, the answer to which is present in the passage. The answer to this question should be completely and unambiguously found in the passage. The query must be about a single or multiple linked entities. 
Input: It can take two forms: caustic gouging or caustic cracking, also called caustic embrittlement. Caustic attack or caustic corrosion, is often encountered in phosphate treated boilers in which deposits of phosphates or other ‘scale’ occur in high heat transfer areas. Boiler water can permeate the porous deposit resulting in localize corrosion. #5. Boiler water pH and PO4 levels need to be in balance, a balance moreover that depends on the operating pressure. In the drum the concentration of chemicals is usually higher than in the boiler feedwater, especially for those (added) compounds that aren't taken out by the steam. water treatment, causing highly alkaline conditions. In boilers, the source of this corrosion is excessive use of hydrazine, or leaking internal de-super-heater elements in boiler drums, which allow alkaline Phosphates-dispersants, polyphosphates-dispersants (softening chemicals): reacting with the alkalinity of boiler water, these products neutralize the hardness of water by forming tricalcium phosphate, and insoluble compound that can be disposed and blow down on a continuous basis or periodically through the bottom of the boiler. Boiler water carryover. Boiler water carryover is the contamination of steam with boiler water solids. Common causes of boiler water carryover are: Bubbles or foam form on the surface of the boiler water and leave with the steam. This is due to high concentrations of insoluble or soluble solids in the boiler water. Criteria: The following criteria for total phosphorus were recommended by US EPA (1986): 1  1. no more than 0.1 mg/L for streams which do not empty into reservoirs, 2  2. no more than 0.05 mg/L for streams discharging into reservoirs, and. 3  3. no more than 0.025 mg/L for reservoirs. Boiler water. Boiler water is the liquid phase of steam within a boiler. The term may also be applied to raw water intended for use in boilers, treated boiler feedwater, steam condensate being returned to a boiler, or boiler blowdown being removed from a boiler. Ph And Phosphate Concentration In Bfw And Steam Drum - posted in Industrial Professionals: Boiler feed water (BFW) pH is to be maintained in the range of 8.0 to 9.5(guidelines) where as in steam drum pH maintaining guidelines is in the range of 9.5 to 11.0. Pressure of steam drum is 34 barg. In general, softening chemicals (phosphates, soda ash, caustic, etc.) are added directly to the fee-water at a point near the entrance to the boiler drum. They may also be fed through a separate line discharging in the feed-water drum of the boiler. Boiler Feedwater Treatment (Part I): Why Water Treatment is Necessary Contents. Water for boilers; Impurities in water; Boiler feedwater; Purity requirements of feedwater; Boiler deposits; Corrosion; Boiler water carryover; Water for boilers. All natural waters contain varying amounts of suspended and dissolved matter as well as dissolved gases.
Output:
effect of phosphate in boiler water