What is the acceptable chloride value of boiler water?
What is the acceptable chloride value of boiler water?
Formation of chloride ions can be done by controlling the amount and time of boiler blow down. Standard value of chloride ion is less than 300 mg Cl/l. When calcium phosphates is formed it precipitates on the water surface and can be easily removed by blow down.
What is the normal range in ppm of chloride in boiler water?
Boiler water test
| Table 1 – Recommended boiler water characteristics | ||
|---|---|---|
| Boiler pressure bar | pH | Chlorides max ppm CI |
| 0-15 | 10.5-11.5 | 300 |
| 15-30 | 10.5-11.5 | 150 |
What issue do chlorides cause in boilers?
When chlorides are present at an unacceptable level, chloride stress cracking can also occur. Corrosion typically occurs in the parts of the boiler that are heated the most, where high temperatures and cracking in the metals accelerate the breakdown of the materials.
What is the purpose of chloride test in boiler water?
The chloride test is used (often in conjunction with the conductivity test) to regulate boiler blowdown. Blowdown is necessary to keep boiler solids (both dissolved and precipitated) from building up to the level where they might cause scale and carryover.
What is the allowed chloride content?
Threshold chloride concentration values vary but are typically in the range of 0.05 to 0.1% by weight of concrete – about 2 to 4 lbs/yd3. Chloride limits are expressed on the basis of the weight of portland cement.
How do you reduce chloride in water?
The most common water treatment devices for reducing the chloride content of drinking water are reverse osmosis, anion exchange or distillation treatment systems.
What is the ideal pH for boiler water?
pH 11
Boiler water should be maintained at pH 11. Generally, the higher the pH (basic), the less soluble some solids are in the water. The lower the pH (acidic), the more soluble these solids are.
What are the problems may cause if there is chloride sulfate in a boiler feed water?
Chloride and sulfate ions adversely affect the corrosion resistance of most metals and the presence of 100 ppm chloride ions in the water causes pitting corrosion of steel [5] . The chloride ions cause the passive film to break down at certain weak spots on the metal surface and assist corrosion. …
How do you test a water chloride boiler?
To start this test, fill the 100ml beaker with sample water. Next, dissolve chloride tabs one by one until the color of the water changes from yellow to brown. Depending on the number of pills we use, we can then determine the chloride concentration of the water (use the color indicator to determine the levels).
What is the maximum limit ppm for chloride in water?
Cl levels in process waters are controlled to about 650 ppm maximum.
What is chloride threshold?
The chloride threshold, also often referred to as the critical chloride content, is the concentration of chloride in concrete required to break down the passive layer (i.e., depassivate) of the reinforcement that may lead to corrosion initiation.
What should the concentration of chloride in boiler water be?
If ten cycles of concentration are permissible for a given boiler, then the concentration of chlorides should never exceed ten times that of the makeup water. For example, the makeup water chloride concentration is 10ppm so the boiler chloride concentration must never exceed 100ppm.
What should be used to control boiler blow down?
Chlorides, however, are relatively unaffected by other materials in the boiler. When compared to the makeup water chloride concentration, boiler water chloride concentration will most accurately show the cycles of concentration of a boiler. Consequently, chlorides should be used to control boiler blow down.
What happens to the water level in a steam boiler?
As the steam load increases, the water level in the boiler falls more quickly and activates the feed water pumps more often and/or for a longer period of time. Consequently, the chemical addition pump(s) adjust feed rate(s) automatically.
What happens to copper in a high pressure boiler?
In high pressure boiler, by using the sodium sulphite, the sulphite can break down to give hydrogen sulphide which can attack steel brass and copper. If chloride is found too much in your boiler water what will you do? Reduce the boiler load to minimum. If highly contaminant shut down completely and wash out.
