- ASTM A192 Steel Tubes for High-pressure Steel Boiler Tube
- Hardness testing methods of high-pressure boiler tubes
- Difference between thread pipe and spiral pipe
- Boiler tube quality problems
- What is boiler pickling
- 20G seamless steel pipe for boiler
- GB5310 20G boiler steel pipe
- Boiler pipe forming
- Characteristics of boiler pipe
- Heat boiler seamless extrusion technology
- Low and medium pressure boiler pipe
- High-pressure boiler tube heat defect
Boiler pipe often accumulate oxide or other contaminants in the process of manufacturing, transportation and installation, boiler heating surface corrosion damage in the initial running.
The the boiler has safely operated for a period of time, in the high heat load area (such as a burner zone) occurs oxide deposition of the pipe wall, resulting in over-temperature of the heating surface or tube rupture.
Natural water is an aqueous solution of electrolyte contact with the metal can easily generate electrochemical corrosion, salt scale deposition in the steam valve failure and valve leak may cause the valve action. , Boiler installed and ready to run in respect of a series of measures to ensure the cleaning of the heating surfaces.
Boiler pickling operations beginning, Condenser --- feedwater system should be kept filled with demineralized water. And chemical cleaning pump equipment at full capacity flow corresponding to the establishment of recycling, including low-pressure heaters, deaerator, as well as high-pressure heaters, feed pumps should bypass. After the pickling cycle, and the fluid within the system reaches 200F, glycolic acid, formic acid and ammonium chloride inhibitors mixed solution was injected into the system. To ensure the uniformity of the concentration, the acid solution should be injected at a constant rate, i.e. the injection time equal to one complete cycle through the system needs time. Pickling is complete, it can be used in addition to the saline-filled system to discharge waste pickling solution and flush the system. Of condensate should pickling after filling containing 40ppm ammonia and 500ppm hydrazine to inactivate the system. Passivation during the operation, the pH value should be maintained at 9. O or greater, hydrazine concentration above 200ppm. Note that if some of the parts made of stainless steel of the feedwater heater, can not spend France formulated solution pickling.
With caustic period, there may have been suspended solids abrasion damage to the acid solution, or wash pumps and other equipment should be bypassed or remove the inner member. Valves and pipes should be checked to prevent acid accidental discharge, or equipment of accidental contamination. Should continue to cycle in the pickling solution, the first time after the return from the high-pressure heater 4-6 hours, once every half an hour in water samples sampling and analysis of the iron content. Feedwater heater bypass cleaning should change the fluid flow paths in the pickling period.
