What is the typical pH value for boiler feedwater?
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What is the typical pH value for boiler feedwater?
In accordance with GB1576-2008
Industrial boilers are subject to the GB1576-2008 standard, which requires that the pH of the feedwater be greater than or equal to 7; a value lower than 7 is not allowed. GB/T12145-1999 specifies the required pH levels for feedwater in thermal power generation units and steam power equipment: For drum boilers: 1. For pressures of 3.8–5.8 MPa, the pH should be 8.8–9.2; 2. For pressures of 5.9–18.3 MPa, it should be 8.8–9.3 in copper-based systems and 9.0–9.5 in copper-free systems. For once-through boilers, the requirements are the same as those specified in point 2 above
When considering boiler feed water, it’s not enough to only look at the pH value; factors such as water hardness and temperature also need to be taken into account. The water hardness is 0.03, and the temperature should be kept at 50 degrees. This is very beneficial for the long-term stable operation of the furnace
Low-pressure boilers comply with GB1576-2008. Boilers of medium pressure and above shall comply with GB12145-1999. Finding these two national standards will resolve the issue. Since I don’t know the pressure of your boiler, the parameters cannot be determined.
Yes, power station boilers are governed by GB12145-99; the requirements regarding boiler water quality are specified in the standard of the People’s Republic of China titled \"Water and Steam Quality for Thermal Power Generating Units and Steam Power Equipment\", GB12145-99, which covers the quality of boiler feedwater, boiler water, and steam. Water supply quality standards: Hardness, dissolved oxygen, iron, pH (25°C), oil, copper – ≤2 umol/L, ≤15 ug/L, ≤50 ug/L, 8.8~9.2; <1.0 mg/L, ≤10 ug/L. Boiler water quality standards: Phosphates, chloride ions, silica, pH (25°C) – 5~15 mg/L, ≤4 mg/L, ≤2.0 mg/L, 9~11
Our waste heat boiler for sulfuric acid production uses medium pressure, with the boiler feed water pH maintained at 8.8 to 9.2
We keep the water level at 8.5-9.2
We use waste heat steam boilers. Keep the pH between 10 and 12.
It’s not just the pH that matters; factors such as calcium, chloride, total alkalinity, solid particles, iron, phosphate, and hardness in the water also play a role. These are all prerequisites for improving the quality of deoxygenated water.
The pH value should indicate weakly alkaline water; a value between 9 and 10 is generally ideal. Of course, other parameters of the water also need to be taken into consideration.