4BE3 U6 C2 Obj 3 EMH

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Questions and Answers

EASY Where should tests be conducted?

In an open space, preferably beneath a fume hood

What should you do before taking a sample from a boiler?

Clean the sampling containers and rinse them with water from the sampling line

Why is it important to cool the sample in a sample cooler?

To prevent dissolved and solid particles from settling out

What is the purpose of a sample cooler?

To cool the sample to a standard temperature Signup and view all the answers

What is used to deliver titration reagents to samples?

A burette Signup and view all the answers

What is the purpose of an automatic sampling arrangement?

To automatically sample the boiler water and test for different characteristics Signup and view all the answers

Why is it important to read the SDS for any unfamiliar chemicals?

To follow the safety guidelines for handling the chemical Signup and view all the answers

What should you do with the sampling containers before taking a sample?

Clean and rinse them with water from the sampling line Signup and view all the answers

What is the purpose of a fume hood in the testing area?

To minimize fume accumulation Signup and view all the answers

What type of water is used for final rinsing of equipment before and after use?

Distilled water Signup and view all the answers

What is the hardness test measuring?

The amount of calcium and magnesium ions in water Signup and view all the answers

Why is it important to maintain a certain pH level in boiler water?

To prevent scaling Signup and view all the answers

What is the purpose of the calcium magnesium hardness buffer in the hardness test?

To indicate the presence of hardness in the sample Signup and view all the answers

Why is it important to recalibrate the pH meter probe?

To increase the accuracy of the pH reading Signup and view all the answers

What is the desired pH range for most boilers?

pH 9.5 to 10.5 Signup and view all the answers

What is the consequence of a strongly basic environment in boiler water?

Corrosion is increased Signup and view all the answers

What is the purpose of the colour comparison test?

To determine the pH level of water Signup and view all the answers

What should the operator do if the boiler phosphate residual is low?

Perform hardness tests on various condensate returns Signup and view all the answers

What does a high condensate pH indicate?

An overfeed of neutralizing amine Signup and view all the answers

Why is it important to follow the prescribed test procedures?

To ensure accurate results Signup and view all the answers

What determines the required water treatment equipment in a plant?

The characteristics of the source water and the needs of the equipment in the plant Signup and view all the answers

What is the purpose of daily testing and recording in a chemical log book?

To verify that the water treatment equipment is working correctly Signup and view all the answers

What is the most important part of any treatment program?

Making the dosing adjustments necessary for maintaining correct boiler water chemistry Signup and view all the answers

Who works with chemical suppliers to develop control ranges for plant water treatment systems?

Power Engineers Signup and view all the answers

What is the purpose of testing boiler water?

To identify the nature and amount of impurities present in the boiler water Signup and view all the answers

Why is it important to wear safety gear when testing boiler water?

To protect against splashes, burns, and respiratory harm Signup and view all the answers

What should be worn when working with acids or bases?

Splash apron and acid/base resistant gloves Signup and view all the answers

Why is it important to have respiratory protection when testing boiler water?

To protect against respiratory harm from specific materials Signup and view all the answers

What is the purpose of adding sodium sulfite to the feedwater system?

To protect the deaerator, feedwater lines, and boiler from corrosion Signup and view all the answers

Why is it important to fill the sample bottle to the top and exclude air when taking a boiler water sample?

To prevent a false low reading of sulfite residual Signup and view all the answers

What is the purpose of the acid starch indicator in the sulfite residual test?

To indicate the end point of the titration reaction Signup and view all the answers

What is the usual range of sulfite residual maintained in operating boilers?

20-60 ppm Signup and view all the answers

What is the purpose of adding sodium phosphate to the boiler water?

To prevent scale formation by reacting with calcium and magnesium ions Signup and view all the answers

What is the purpose of cooling and filtering the boiler water sample before performing the phosphate residual test?

To ensure a accurate reading of the phosphate residual Signup and view all the answers

What is the consequence of excessively high sodium sulfite levels in the boiler water?

Increased scale formation Signup and view all the answers

What is the consequence of low sodium sulfite levels in the boiler water?

Increased waterside corrosion Signup and view all the answers

What is the purpose of the sulfite residual test?

To measure the sulfite residual in the boiler water Signup and view all the answers

What is the consequence of not maintaining the correct sulfite residual level in the boiler water?

Increased waterside corrosion or pitting corrosion Signup and view all the answers

What is the potential consequence of excessively high boiler water pH?

Caustic embrittlement, cracking, and gouging Signup and view all the answers

What is the purpose of reducing the feed of caustic soda (NaOH) to the boiler?

To prevent caustic embrittlement, cracking, and gouging Signup and view all the answers

What is the consequence of excessively low boiler water pH?

Acidic corrosion Signup and view all the answers

What is the purpose of the P and M alkalinity test?

To determine the hydroxyl (OH-) alkalinity Signup and view all the answers

What is the unit of measurement for conductivity?

Millisiemens per centimeter Signup and view all the answers

What happens when the TDS is high?

The continuous blowdown valve should be opened more Signup and view all the answers

What is the purpose of molybdate in boiler treatment?

To inhibit corrosion Signup and view all the answers

What is the purpose of the molybdenum test?

To determine the residual molybdate levels Signup and view all the answers

What is the first step in the molybdate test procedure?

Measure and filter a 50 ml sample into a flask Signup and view all the answers

What is the endpoint of the molybdate test?

A pale yellow color develops Signup and view all the answers

What is alkalinity a measure of in a solution?

Ability to resist changes in pH Signup and view all the answers

What is the purpose of testing source water alkalinity?

To determine the efficacy of the feedwater treatment program Signup and view all the answers

What is the function of phenolphthalein indicator in the P-alkalinity test?

To indicate the presence of hydroxides and carbonates Signup and view all the answers

What is the formula to calculate P-alkalinity in ppm of CaCO3?

ml of titrant × 20 Signup and view all the answers

What is the purpose of the M-alkalinity test?

To determine the total alkalinity of the boiler water Signup and view all the answers

What is the formula to calculate M-alkalinity in ppm of CaCO3?

ml of titrant × 20 Signup and view all the answers

What is the relationship between OH– and HCO3– alkalinity?

They cannot exist together in solution Signup and view all the answers

How is OH– alkalinity calculated from the P-alkalinity and M-alkalinity tests?

2P - M Signup and view all the answers

What is the purpose of the molybdate test?

To determine the Molybdenum as Mo concentration Signup and view all the answers

What is the control range recommended by the water treatment company for?

Molybdenum as Mo concentration Signup and view all the answers

What should be done when the phosphate concentration is excessively high?

Reduce or halt the amount of phosphate fed to the boiler Signup and view all the answers

What is the consequence of excessively low phosphate levels?

Scale formation Signup and view all the answers

What should the operator do when the phosphate residual is low?

Increase the phosphate feed rate Signup and view all the answers

What should be recorded on the water treatment log sheet?

The results of all the water tests Signup and view all the answers

What should the operator do if there is an unusual drop in phosphate?

Check the hardness of the condensate and softener effluent Signup and view all the answers

What is the purpose of the water treatment log sheet?

To compare the latest results with those of previous water tests Signup and view all the answers

What should be done with the reading of 7.9 mg/L PO43–?

Review the previous test and check the trend Signup and view all the answers

What is the result of excessively high phosphate levels?

Foaming and carryover Signup and view all the answers

What is the formula to calculate OH– alkalinity?

2P - M Signup and view all the answers

What is the unit of measurement for alkalinity test results?

ppm CaCO3 Signup and view all the answers

What is the purpose of maintaining a minimum level of OH– alkalinity in boiler water?

To neutralize acidic conditions and reduce scale deposition Signup and view all the answers

What happens if the total alkalinity is excessively high?

Foaming or carryover may occur Signup and view all the answers

What is the consequence of excessively low OH– alkalinity in boiler water?

Waterside corrosion may occur Signup and view all the answers

What is the formula to calculate CO32– alkalinity when P is greater than one half of M?

2(M - P) Signup and view all the answers

What is the consequence of excessively high OH– alkalinity in boiler water?

Caustic gouging or destabilization of protective magnetite layers may occur Signup and view all the answers

What is the purpose of increasing the rate of continuous blowdown in boiler operation?

To reduce the risk of caustic embrittlement Signup and view all the answers

What is the consequence of excessively low total alkalinity in boiler water?

A costly loss of boiler water, chemicals, and heat energy may occur Signup and view all the answers

What is the role of NaOH in a coordinated phosphate treatment program?

To be eliminated until the OH– alkalinity drops Signup and view all the answers

MEDIUM What is the primary factor in determining the required water treatment equipment in a plant?

The characteristics of the source water Signup and view all the answers

What is the purpose of testing the water treatment equipment and chemical effectiveness?

To ensure proper system chemistry Signup and view all the answers

What should the operator do to stay within the control ranges?

Adjust the chemical feed, blowoff, and blowdown as required Signup and view all the answers

Why is it important to wear safety gear when testing boiler water?

To prevent injury from splashes and burns Signup and view all the answers

What is the purpose of daily testing and recording in a chemical log book?

To track the effectiveness of the treatment program Signup and view all the answers

What is the primary purpose of the P-Alkalinity test?

To measure the hydroxide and carbonate alkalinity in the boiler water Signup and view all the answers

Who is responsible for developing control ranges for plant water treatment systems?

The Power Engineer and chemical supplier jointly Signup and view all the answers

What is the primary purpose of testing boiler water?

To determine the nature and amount of impurities present Signup and view all the answers

What is the endpoint of the phenolphthalein alkalinity test?

pH 8.2 to 8.3 Signup and view all the answers

What is the most important part of any treatment program?

Making dosing adjustments to maintain correct boiler water chemistry Signup and view all the answers

What is the formula to calculate the P-Alkalinity (P) as ppm of CaCO3?

ml of titrant × 20 Signup and view all the answers

What is the purpose of the M-Alkalinity test?

To measure the total alkalinity in the boiler water Signup and view all the answers

What is the formula to calculate the M-Alkalinity (M) as ppm of CaCO3?

ml of titrant × 20 Signup and view all the answers

What is the purpose of the methyl purple indicator in the M-Alkalinity test?

To indicate the endpoint of the titration Signup and view all the answers

What is the relationship between P-Alkalinity and OH- alkalinity?

P-Alkalinity is equal to OH- alkalinity and half of the CO32- alkalinity Signup and view all the answers

How is the OH- alkalinity calculated from the P-Alkalinity and M-Alkalinity tests?

OH- = 2P - M Signup and view all the answers

What is the purpose of the alkalinity tests in boiler water treatment?

To measure the ability of the boiler water to resist changes in pH Signup and view all the answers

What is alkalinity a measure of in a solution?

The ability of the solution to resist changes in pH Signup and view all the answers

What is the main reason for conducting hardness tests on raw water entering a plant site?

To determine the total amount of calcium and magnesium ions present in the water Signup and view all the answers

What is the purpose of adding calcium magnesium hardness buffer to the water sample during the hardness test?

To prepare the sample for titration Signup and view all the answers

What is the significance of a pH level below 8.5 in boiler water?

It increases the risk of corrosion Signup and view all the answers

What is the primary purpose of using a fume hood in the testing area?

To prevent the accumulation of fumes Signup and view all the answers

What is the purpose of recalibrating the pH meter probe?

To increase the accuracy of the pH readings Signup and view all the answers

Why is it important to rinse the sampling containers before taking a sample?

To prevent contamination of the sample Signup and view all the answers

What action should the operator take if the boiler phosphate residual is low?

Perform hardness tests on various condensate returns Signup and view all the answers

What is the purpose of using an automatic sampling arrangement?

To continuously test for different characteristics of the boiler water Signup and view all the answers

What is the consequence of an overfeed of neutralizing amine in boiler water?

It results in excessively high condensate pH Signup and view all the answers

What is the purpose of using a sample cooler?

To cool the sample to a standard temperature Signup and view all the answers

What is the purpose of titrating the water sample with sodium EDTA solution during the hardness test?

To determine the total hardness of the water Signup and view all the answers

What is the significance of a high hardness value in boiler water?

It indicates the presence of scaling compounds Signup and view all the answers

Why is it important to follow the plant's testing and safety procedures?

To minimize the risk of accidents and injuries Signup and view all the answers

What is the purpose of the triple rinse of the sampling container with the sample water?

To reduce the risk of contamination of the sample Signup and view all the answers

What is the purpose of using an electronic pH meter to measure the pH level of boiler water?

To measure the pH level accurately and quickly Signup and view all the answers

What should the operator do if the hardness test result shows a high hardness value in the outlet of the water softener?

Regenerate the water softener Signup and view all the answers

What should be done with the sample after it is taken?

It should be sealed to prevent contamination Signup and view all the answers

Why is it important to read the SDS for any unfamiliar chemicals?

To follow the safety guidelines and precautions Signup and view all the answers

What is the purpose of using distilled water for final rinsing of equipment?

To ensure the equipment is clean and free of impurities Signup and view all the answers

Why is it important to take a sample from a representative location?

To ensure the sample is representative of the boiler water Signup and view all the answers

What should the operator do if the boiler phosphate residual is low?

Increase the phosphate feed rate Signup and view all the answers

What is the consequence of excessively high phosphate concentration in the boiler?

Foaming and carryover Signup and view all the answers

What should be checked when there is an unusual drop in phosphate concentration?

Condensate and softener effluent for hardness Signup and view all the answers

What is the purpose of the water treatment log sheet?

To record water test results Signup and view all the answers

What happens when phosphate concentrations fall in an operating boiler?

Phosphate feed rate decreases Signup and view all the answers

What is the result of excessively low phosphate concentration in the boiler?

Scale formation Signup and view all the answers

What happens when the timer expires during the phosphate residual test?

The meter resets to zero Signup and view all the answers

Where should the operator record the phosphate concentration reading?

Water treatment log sheet Signup and view all the answers

What is the consequence of excessively high boiler water pH?

Increased risk of caustic embrittlement, cracking, and gouging Signup and view all the answers

Why is it important to know the hydroxyl (OH-) alkalinity in boiler water?

It is more important than knowing the pH level in boiler water Signup and view all the answers

What is the purpose of increasing the rate of continuous blowdown in a boiler?

To reduce the amount of dissolved solids in the boiler water Signup and view all the answers

What is the consequence of excessively low boiler water pH?

Increased risk of acidic corrosion Signup and view all the answers

What is the purpose of using molybdate in boiler treatment?

To act as a corrosion inhibitor Signup and view all the answers

What is the unit of measurement for conductivity in a conductivity meter?

Microsiemens per centimeter (μS/cm) Signup and view all the answers

What is the purpose of the molybdenum test?

To determine the residual molybdate levels in the boiler water Signup and view all the answers

What happens when the total dissolved solids (TDS) in a boiler water is high?

Foaming, priming, and carryover occur Signup and view all the answers

Why is it important to reduce the amount of blowdown and blowoff in a boiler?

To reduce water, heat energy, and chemical waste Signup and view all the answers

What is the purpose of the P and M alkalinity test in boiler water treatment?

To determine the hydroxyl alkalinity in the boiler water Signup and view all the answers

What is the mathematical relationship between P, M, and OH– alkalinity?

OH– = 2P - M Signup and view all the answers

If P > ½M, what is the formula to determine CO32– alkalinity?

CO32– = 2(M - P) Signup and view all the answers

What is the consequence of excessively high total alkalinity in boiler water?

Foaming or carryover Signup and view all the answers

Why is it necessary to maintain a minimum level of OH– alkalinity in boiler water?

To neutralize acidic conditions and prevent corrosion Signup and view all the answers

What is the consequence of excessively high OH– alkalinity in boiler water?

Caustic gouging and destabilization of protective magnetite layers Signup and view all the answers

What is the purpose of sodium sulfite in boiler water treatment?

To remove dissolved oxygen and prevent corrosion Signup and view all the answers

What is the unit of measurement for P and M alkalinity tests?

Parts per million (ppm) as CaCO3 Signup and view all the answers

What is the consequence of excessively low OH– alkalinity in boiler water?

Waterside corrosion and decreased effectiveness of phosphate treatment Signup and view all the answers

What is the purpose of the P and M alkalinity test in boiler water treatment?

To determine the concentration of alkalinity species in boiler water Signup and view all the answers

What should the operator do if the total alkalinity is excessively high?

Increase the rate of continuous blowdown and bottom blowoff Signup and view all the answers

What is the primary purpose of adding sodium sulfite to the boiler water?

To eliminate the presence of dissolved oxygen Signup and view all the answers

What is the recommended range of sulfite residual maintained in operating boilers?

20 to 60 ppm Signup and view all the answers

What is the consequence of excessively high sodium sulfite levels in the boiler water?

Increased sludge and scale formation Signup and view all the answers

What is the purpose of the acid starch indicator in the sulfite residual test?

To indicate the presence of sulfite Signup and view all the answers

What is the consequence of low sodium sulfite levels in the boiler water?

Increased corrosion rate Signup and view all the answers

What is the purpose of adding sodium phosphate to the boiler water?

To prevent scale formation Signup and view all the answers

Why is it important to cool and filter the boiler water sample before performing the phosphate residual test?

To prevent interference from other chemicals Signup and view all the answers

What is the recommended range of phosphate residual maintained in operating boilers?

20 to 60 ppm Signup and view all the answers

What is the purpose of the sulfite residual test?

To determine the level of sulfite residual Signup and view all the answers

What is the consequence of not maintaining the correct sulfite residual level in the boiler water?

Increased corrosion rate Signup and view all the answers

What is the primary purpose of water analysis for the raw water supply?

To identify the required water treatment equipment Signup and view all the answers

Why is daily testing and recording in a chemical log book crucial?

To ensure proper system chemistry Signup and view all the answers

What is the primary responsibility of Power Engineers in water treatment?

To develop control ranges for plant water treatment systems Signup and view all the answers

What is the most critical aspect of any treatment program?

Making dosing adjustments for correct boiler water chemistry Signup and view all the answers

Why is it essential to wear protective gear when testing boiler water?

To protect against chemical splashes Signup and view all the answers

What is the primary purpose of testing boiler water?

To determine the nature and amount of impurities Signup and view all the answers

What determines the required water treatment equipment in a plant?

The local water chemistry and equipment needs Signup and view all the answers

Who is responsible for adjusting chemical feed, blowoff, and blowdown?

The plant operator Signup and view all the answers

What is the primary reason for ensuring the sample is representative of the boiler water?

To ensure accurate results for the water treatment program Signup and view all the answers

What is the primary purpose of using a compression fitting in a sample cooler?

To prevent flash-off and settlement of dissolved particles Signup and view all the answers

What is the primary advantage of using an automatic sampling arrangement in a power plant?

It reduces the need for manual sampling and testing Signup and view all the answers

What is the primary purpose of having a supply of distilled water in the testing area?

To maximize the accuracy of results during titration Signup and view all the answers

What is the primary reason for ensuring the testing area is well-ventilated and equipped with a fume hood?

To prevent the accumulation of fumes during testing Signup and view all the answers

What is the primary purpose of using a burette in titration?

To deliver a precise amount of titration reagent to the sample Signup and view all the answers

What is the primary consequence of not following the prescribed test procedures?

Inaccurate results for the water treatment program Signup and view all the answers

What is the primary purpose of testing boiler water in a power plant?

To optimize the water treatment program for the boiler Signup and view all the answers

What is the primary advantage of using an autofill burette in a power plant?

It automates the process of filling the burette with titration reagent Signup and view all the answers

What is the primary purpose of using a sample header in an automatic sampling arrangement?

To deliver the sample to the automatic analyzers Signup and view all the answers

What is the primary function of phenolphthalein indicator in the P-alkalinity test?

To indicate the presence of hydroxide ions Signup and view all the answers

What is the purpose of the M-alkalinity test?

To determine the total alkalinity Signup and view all the answers

What is the unit of measurement for P-alkalinity and M-alkalinity?

ppm of CaCO3 Signup and view all the answers

What is the primary reason for reducing the feed of caustic soda (NaOH) to the boiler?

To prevent caustic embrittlement and gouging Signup and view all the answers

What is the consequence of excessively low boiler water pH?

Acidic corrosion and inhibited phosphate compounds Signup and view all the answers

How is the OH- alkalinity calculated?

By subtracting M-alkalinity from 2P Signup and view all the answers

What is the purpose of the P and M alkalinity test?

To determine the hydroxyl (OH–) alkalinity Signup and view all the answers

What is the reaction that occurs when a sample is titrated with sulfuric acid in the P-alkalinity test?

All of the above Signup and view all the answers

What is the purpose of the molybdenum test?

To determine the molybdenum residual in the boiler water Signup and view all the answers

What happens when the total dissolved solids (TDS) content is high?

Foaming, priming, and carryover occur Signup and view all the answers

What is the relationship between P-alkalinity and OH- alkalinity?

P-alkalinity is equal to OH- alkalinity plus half the carbonate alkalinity Signup and view all the answers

What is the purpose of increasing the rate of continuous blowdown?

To reduce the total dissolved solids (TDS) content Signup and view all the answers

What is the consequence of excessively low total dissolved solids (TDS) content?

Excessive blowdown and blowoff, wasting water and energy Signup and view all the answers

What is the purpose of the alkalinity tests?

To determine the types of alkalinity present in the boiler water Signup and view all the answers

What is the unit of measurement for conductivity?

Microsiemens per centimeter (μS/cm) Signup and view all the answers

What is the effect of high alkalinity on the boiler water?

It increases the risk of corrosion Signup and view all the answers

What is the purpose of molybdate in boiler treatment?

To act as a corrosion inhibitor Signup and view all the answers

What is the purpose of the P-alkalinity and M-alkalinity tests?

To determine the types of alkalinity present in the boiler water Signup and view all the answers

What is the endpoint of the molybdate test?

A pale yellow color is observed Signup and view all the answers

What is the consequence of not maintaining the correct sulfite residual level in the boiler water?

Acidic corrosion and oxygen pitting Signup and view all the answers

What is the primary reason for performing hardness tests on raw water entering a plant site?

To measure the amount of calcium and magnesium ions present Signup and view all the answers

What is the consequence of not following the prescribed test procedures for water testing?

The results will vary widely and may not be valid Signup and view all the answers

What is the purpose of titrating with sodium EDTA solution in the hardness test?

To reach a single drop endpoint Signup and view all the answers

What is the desired pH range for most boilers?

pH 9.5 to 10.5 Signup and view all the answers

HARD What is the consequence of excessively high phosphate levels in a boiler?

Foaming and carryover Signup and view all the answers

What is the consequence of a strongly basic environment in boiler water?

Increased scale formation Signup and view all the answers

What should the operator do if the boiler phosphate residual is low?

Increase the phosphate feed rate Signup and view all the answers

What is the purpose of testing condensate returns?

To pinpoint the source of hardness contamination Signup and view all the answers

What is the purpose of recording water test results on the water treatment log sheet?

To compare results with previous tests Signup and view all the answers

What is the consequence of excessively high condensate pH?

Overfeed of neutralizing amine Signup and view all the answers

What is the purpose of recalibrating the pH meter probe?

To increase the accuracy of the pH meter Signup and view all the answers

What should the operator do if there is an unusual drop in phosphate concentration?

Check the condensate and softener effluent for hardness Signup and view all the answers

What is the consequence of excessively low phosphate levels in a boiler?

Scale formation Signup and view all the answers

What is the consequence of not regenerating an ion-exchange softener?

Increased hardness in the boiler water Signup and view all the answers

What is the purpose of adding calcium magnesium hardness buffer to the sample in the hardness test?

To indicate the presence of hardness in the water Signup and view all the answers

What is the purpose of reviewing the trend and checking the previous test when phosphate levels are low?

To compare results with previous tests Signup and view all the answers

What is the consequence of not maintaining the correct phosphate levels in a boiler?

Scale formation Signup and view all the answers

What is the purpose of recording test results on the water log sheet?

To compare results with previous tests Signup and view all the answers

What is the mathematical relationship between P and M alkalinity that can be used to determine the concentration of hydroxyl alkalinity in boiler water?

2P – M = OH– Signup and view all the answers

If the majority of the alkalinity is due to bicarbonate, what is the likely consequence?

Free corrosive carbon dioxide is released Signup and view all the answers

What is the purpose of maintaining a minimum level of OH– alkalinity in boiler water?

To neutralize acidic conditions and prevent waterside corrosion Signup and view all the answers

What is the consequence of excessively low total alkalinity in boiler water?

Costly loss of boiler water, chemicals, and heat energy occurs Signup and view all the answers

What is the purpose of increasing the rate of continuous blowdown when total alkalinity is excessively high?

To prevent foaming or carryover Signup and view all the answers

What is the consequence of excessively high OH– alkalinity in boiler water?

Caustic embrittlement increases Signup and view all the answers

What is the purpose of reducing or eliminating the feed of NaOH to the boiler when OH– alkalinity is excessively high?

To reduce caustic embrittlement Signup and view all the answers

What is the purpose of feeding NaOH to the boiler in small amounts when OH– alkalinity is excessively low?

To neutralize acidic conditions and prevent waterside corrosion Signup and view all the answers

What is the mathematical relationship between P and M alkalinity that can be used to determine the concentration of carbonate alkalinity when P is greater than one half of M?

CO32– = 2(M – P) Signup and view all the answers

What is the purpose of analyzing the results of P and M alkalinity tests?

To determine the predominant species affecting the alkalinity Signup and view all the answers

What is the primary reason for maintaining a sulfite residual in the boiler water?

To prevent waterside corrosion Signup and view all the answers

What is the consequence of excessively high sodium sulfite levels in the boiler water?

Formation of sludge and scale Signup and view all the answers

What is the purpose of the acid starch indicator in the sulfite residual test?

To indicate the end point of the titration Signup and view all the answers

What is the typical range of sulfite residual maintained in operating boilers?

20 to 60 ppm Signup and view all the answers

What is the purpose of cooling and filtering the boiler water sample before performing the phosphate residual test?

To prevent false high readings Signup and view all the answers

What is the consequence of low sodium sulfite levels in the boiler water?

Increased risk of waterside corrosion Signup and view all the answers

What is the purpose of adding sodium phosphate to the boiler water?

To prevent scale formation Signup and view all the answers

What is the purpose of the sulfite residual test?

To determine the level of excess sodium sulfite in the boiler water Signup and view all the answers

What is the consequence of not maintaining the correct sulfite residual level in the boiler water?

Increased risk of waterside corrosion Signup and view all the answers

What is the purpose of the phosphate residual test?

To determine the level of sodium phosphate in the boiler water Signup and view all the answers

Study Notes

Water Treatment Equipment

The required water treatment equipment is determined by the needs of the equipment in the plant and the characteristics of the source water.
Local water chemistry must be known to identify the conditions that need treatment and select and size the equipment.

Testing and Safety

Daily testing and recording in a chemical log book is recommended to ensure proper system chemistry.
Operators must adjust chemical feed, blowoff, and blowdown to stay within control ranges.
When testing boiler water, wear safety gear, including eye protection, protective coveralls, heat-resistant gloves, and a splash apron.
Always conduct tests in an open area, preferably under a fume hood, and follow the plant's testing and safety procedures.

Sampling Methods

A standard sampling process is essential for effective water management.
Ensure the sample is representative of the boiler water, and avoid stagnant water.
Clean sampling containers to ensure accurate results, and rinse them with water from the sampling line before taking the sample.
Cool samples as necessary to prevent settling or flash-off.

Testing Methods

Titration is a method of analysis that allows precise determination of a reaction endpoint.
A burette is used to deliver titration reagents to samples.
Autofill burettes are commonly used in power plants.

Tests

Hardness test: measures the amount of calcium and magnesium ions in water.
pH test: crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conductivity test: measures dissolved solids, which can cause scale and corrosion.
Molybdate test: determines residual molybdate levels to ensure corrosion inhibitors are present.
Alkalinity tests: measure a solution's ability to resist changes in pH, and determine the efficacy of the feedwater treatment program.

Hardness Test

Determines the amount of calcium and magnesium ions in water, which affects scale formation on heating surfaces.
Conducted using a water sample, calcium magnesium hardness buffer, and hardness indicator.
Results are expressed as ppm of equivalent CaCO3.

pH Test

Crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conducted using an electronic pH meter or colour comparison test.
Results are expressed as a pH level, which should be between 9.5 and 10.5 for most boilers.

Dissolved Solids Test

Measures the concentration of dissolved solids, which can cause scale and corrosion.
Conducted using a conductivity meter.
Results are expressed in microsiemens per centimeter (μS/cm) or millisiemens per centimeter (mS/cm).

Molybdate Test

Determines residual molybdate levels to ensure corrosion inhibitors are present.
Conducted using a drop kit and Mo indicator.
Results are expressed as mg/L Molybdenum as Mo.

Alkalinity Tests

Phenolphthalein alkalinity test (P-alkalinity): measures hydroxide and carbonate alkalinity.
Methyl alkalinity test (M-alkalinity): measures hydroxide, carbonate, and bicarbonate alkalinity.
Results are expressed as ppm of CaCO3 equivalent.
Hydroxyl alkalinity (OH-) can be calculated from P-alkalinity and M-alkalinity results.

Operator Response to Tests

Hardness test: adjust chemical feed rate to maintain control range.
pH test: adjust chemical feed rate to maintain control range.
Dissolved solids test: adjust continuous blowdown valve to maintain control range.
Molybdate test: adjust molybdate feed rate to maintain control range.
Alkalinity tests: adjust chemical feed rate to maintain control range and prevent corrosion.### Alkalinity Control
Excessively high total alkalinity requires increasing continuous blowdown and bottom blowoffs to prevent costly losses and maintain boiler water chemistry within prescribed limits.
Excessively low total alkalinity indicates excessive blowdown or blowoff, resulting in losses and destabilized boiler water chemistry; decrease blowdown and blowoff rates.
High OH– alkalinity can cause caustic gouging, destabilization of protective magnetite layers, or caustic embrittlement; increase continuous blowdown or reduce NaOH feed to the boiler.
OH– alkalinity must be present in boiler water to:
- Neutralize acidic conditions preventing waterside corrosion.
- Enable precipitation reactions reducing scale deposition in a coordinated phosphate treatment program.

Sodium Sulfite Control

Dissolved oxygen in boiler water causes corrosion; maintaining a residual of excess sodium sulfite eliminates oxygen.
Sodium sulfite (Na2SO3) combines with dissolved oxygen to form Na2SO4, preventing waterside corrosion.
Sodium sulfite is added to the feedwater system to protect deaerator, feedwater lines, and feedwater pumps, as well as the boiler.
Sulfite residual test procedure involves:
- Taking a representative boiler water sample protected from atmospheric oxygen.
- Measuring a 50 ml sample and adding acid starch indicator.
- Titration with potassium iodide-iodate solution.
- Recording the volume of titrant used and multiplying by 20 to find ppm of excess sodium sulfite.
Operator response to sulfite residual test:
- Adjusting sodium sulfite feed pump setting to maintain 20-60 ppm range for operating boilers and up to 80 ppm for boilers in wet layup.
- Reducing sulfite addition to stabilize concentration within the control range.
- Increasing sulfite feed to address low sulfite residual and prevent pitting corrosion.

Phosphate Control

Sodium phosphate is added directly into the boiler to prevent scale formation by reacting with calcium and magnesium ions, forming precipitates blown off from the boiler.
Phosphate residual is maintained, usually in the range of 20-60 ppm.
Residual phosphate test procedure involves:
- Taking a cooled and filtered boiler water sample.
- Using an electronic meter or color comparison against a standard.
Operator response to residual phosphate test:
- Reducing or halting phosphate feed to the boiler if excessively high, causing foaming and carryover.
- Increasing phosphate feed rate if excessively low, causing scale formation.

Water Treatment Log

Recording test results on the water treatment log sheet, including each piece of equipment in the plant and prescribed control ranges.
Comparing latest results with previous tests and taking specific action based on test results.

Water Treatment Equipment

The required water treatment equipment is determined by the needs of the equipment in the plant and the characteristics of the source water.
Local water chemistry must be known to identify the conditions that need treatment and select and size the equipment.

Testing and Safety

Daily testing and recording in a chemical log book is recommended to ensure proper system chemistry.
Operators must adjust chemical feed, blowoff, and blowdown to stay within control ranges.
When testing boiler water, wear safety gear, including eye protection, protective coveralls, heat-resistant gloves, and a splash apron.
Always conduct tests in an open area, preferably under a fume hood, and follow the plant's testing and safety procedures.

Sampling Methods

A standard sampling process is essential for effective water management.
Ensure the sample is representative of the boiler water, and avoid stagnant water.
Clean sampling containers to ensure accurate results, and rinse them with water from the sampling line before taking the sample.
Cool samples as necessary to prevent settling or flash-off.

Testing Methods

Titration is a method of analysis that allows precise determination of a reaction endpoint.
A burette is used to deliver titration reagents to samples.
Autofill burettes are commonly used in power plants.

Tests

Hardness test: measures the amount of calcium and magnesium ions in water.
pH test: crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conductivity test: measures dissolved solids, which can cause scale and corrosion.
Molybdate test: determines residual molybdate levels to ensure corrosion inhibitors are present.
Alkalinity tests: measure a solution's ability to resist changes in pH, and determine the efficacy of the feedwater treatment program.

Hardness Test

Determines the amount of calcium and magnesium ions in water, which affects scale formation on heating surfaces.
Conducted using a water sample, calcium magnesium hardness buffer, and hardness indicator.
Results are expressed as ppm of equivalent CaCO3.

pH Test

Crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conducted using an electronic pH meter or colour comparison test.
Results are expressed as a pH level, which should be between 9.5 and 10.5 for most boilers.

Dissolved Solids Test

Measures the concentration of dissolved solids, which can cause scale and corrosion.
Conducted using a conductivity meter.
Results are expressed in microsiemens per centimeter (μS/cm) or millisiemens per centimeter (mS/cm).

Molybdate Test

Determines residual molybdate levels to ensure corrosion inhibitors are present.
Conducted using a drop kit and Mo indicator.
Results are expressed as mg/L Molybdenum as Mo.

Alkalinity Tests

Phenolphthalein alkalinity test (P-alkalinity): measures hydroxide and carbonate alkalinity.
Methyl alkalinity test (M-alkalinity): measures hydroxide, carbonate, and bicarbonate alkalinity.
Results are expressed as ppm of CaCO3 equivalent.
Hydroxyl alkalinity (OH-) can be calculated from P-alkalinity and M-alkalinity results.

Operator Response to Tests

Hardness test: adjust chemical feed rate to maintain control range.
pH test: adjust chemical feed rate to maintain control range.
Dissolved solids test: adjust continuous blowdown valve to maintain control range.
Molybdate test: adjust molybdate feed rate to maintain control range.
Alkalinity tests: adjust chemical feed rate to maintain control range and prevent corrosion.### Alkalinity Control
Excessively high total alkalinity requires increasing continuous blowdown and bottom blowoffs to prevent costly losses and maintain boiler water chemistry within prescribed limits.
Excessively low total alkalinity indicates excessive blowdown or blowoff, resulting in losses and destabilized boiler water chemistry; decrease blowdown and blowoff rates.
High OH– alkalinity can cause caustic gouging, destabilization of protective magnetite layers, or caustic embrittlement; increase continuous blowdown or reduce NaOH feed to the boiler.
OH– alkalinity must be present in boiler water to:
- Neutralize acidic conditions preventing waterside corrosion.
- Enable precipitation reactions reducing scale deposition in a coordinated phosphate treatment program.

Sodium Sulfite Control

Dissolved oxygen in boiler water causes corrosion; maintaining a residual of excess sodium sulfite eliminates oxygen.
Sodium sulfite (Na2SO3) combines with dissolved oxygen to form Na2SO4, preventing waterside corrosion.
Sodium sulfite is added to the feedwater system to protect deaerator, feedwater lines, and feedwater pumps, as well as the boiler.
Sulfite residual test procedure involves:
- Taking a representative boiler water sample protected from atmospheric oxygen.
- Measuring a 50 ml sample and adding acid starch indicator.
- Titration with potassium iodide-iodate solution.
- Recording the volume of titrant used and multiplying by 20 to find ppm of excess sodium sulfite.
Operator response to sulfite residual test:
- Adjusting sodium sulfite feed pump setting to maintain 20-60 ppm range for operating boilers and up to 80 ppm for boilers in wet layup.
- Reducing sulfite addition to stabilize concentration within the control range.
- Increasing sulfite feed to address low sulfite residual and prevent pitting corrosion.

Phosphate Control

Sodium phosphate is added directly into the boiler to prevent scale formation by reacting with calcium and magnesium ions, forming precipitates blown off from the boiler.
Phosphate residual is maintained, usually in the range of 20-60 ppm.
Residual phosphate test procedure involves:
- Taking a cooled and filtered boiler water sample.
- Using an electronic meter or color comparison against a standard.
Operator response to residual phosphate test:
- Reducing or halting phosphate feed to the boiler if excessively high, causing foaming and carryover.
- Increasing phosphate feed rate if excessively low, causing scale formation.

Water Treatment Log

Recording test results on the water treatment log sheet, including each piece of equipment in the plant and prescribed control ranges.
Comparing latest results with previous tests and taking specific action based on test results.

Water Treatment Equipment

The required water treatment equipment is determined by the needs of the equipment in the plant and the characteristics of the source water.
Local water chemistry must be known to identify the conditions that need treatment and select and size the equipment.

Testing and Safety

Daily testing and recording in a chemical log book is recommended to ensure proper system chemistry.
Operators must adjust chemical feed, blowoff, and blowdown to stay within control ranges.
When testing boiler water, wear safety gear, including eye protection, protective coveralls, heat-resistant gloves, and a splash apron.
Always conduct tests in an open area, preferably under a fume hood, and follow the plant's testing and safety procedures.

Sampling Methods

A standard sampling process is essential for effective water management.
Ensure the sample is representative of the boiler water, and avoid stagnant water.
Clean sampling containers to ensure accurate results, and rinse them with water from the sampling line before taking the sample.
Cool samples as necessary to prevent settling or flash-off.

Testing Methods

Titration is a method of analysis that allows precise determination of a reaction endpoint.
A burette is used to deliver titration reagents to samples.
Autofill burettes are commonly used in power plants.

Tests

Hardness test: measures the amount of calcium and magnesium ions in water.
pH test: crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conductivity test: measures dissolved solids, which can cause scale and corrosion.
Molybdate test: determines residual molybdate levels to ensure corrosion inhibitors are present.
Alkalinity tests: measure a solution's ability to resist changes in pH, and determine the efficacy of the feedwater treatment program.

Hardness Test

Determines the amount of calcium and magnesium ions in water, which affects scale formation on heating surfaces.
Conducted using a water sample, calcium magnesium hardness buffer, and hardness indicator.
Results are expressed as ppm of equivalent CaCO3.

pH Test

Crucial for safe boiler operation, as acidic or basic environments can cause corrosion.
Conducted using an electronic pH meter or colour comparison test.
Results are expressed as a pH level, which should be between 9.5 and 10.5 for most boilers.

Dissolved Solids Test

Measures the concentration of dissolved solids, which can cause scale and corrosion.
Conducted using a conductivity meter.
Results are expressed in microsiemens per centimeter (μS/cm) or millisiemens per centimeter (mS/cm).

Molybdate Test

Determines residual molybdate levels to ensure corrosion inhibitors are present.
Conducted using a drop kit and Mo indicator.
Results are expressed as mg/L Molybdenum as Mo.

Alkalinity Tests

Phenolphthalein alkalinity test (P-alkalinity): measures hydroxide and carbonate alkalinity.
Methyl alkalinity test (M-alkalinity): measures hydroxide, carbonate, and bicarbonate alkalinity.
Results are expressed as ppm of CaCO3 equivalent.
Hydroxyl alkalinity (OH-) can be calculated from P-alkalinity and M-alkalinity results.

Operator Response to Tests

Hardness test: adjust chemical feed rate to maintain control range.
pH test: adjust chemical feed rate to maintain control range.
Dissolved solids test: adjust continuous blowdown valve to maintain control range.
Molybdate test: adjust molybdate feed rate to maintain control range.
Alkalinity tests: adjust chemical feed rate to maintain control range and prevent corrosion.### Alkalinity Control
Excessively high total alkalinity requires increasing continuous blowdown and bottom blowoffs to prevent costly losses and maintain boiler water chemistry within prescribed limits.
Excessively low total alkalinity indicates excessive blowdown or blowoff, resulting in losses and destabilized boiler water chemistry; decrease blowdown and blowoff rates.
High OH– alkalinity can cause caustic gouging, destabilization of protective magnetite layers, or caustic embrittlement; increase continuous blowdown or reduce NaOH feed to the boiler.
OH– alkalinity must be present in boiler water to:
- Neutralize acidic conditions preventing waterside corrosion.
- Enable precipitation reactions reducing scale deposition in a coordinated phosphate treatment program.

Sodium Sulfite Control

Dissolved oxygen in boiler water causes corrosion; maintaining a residual of excess sodium sulfite eliminates oxygen.
Sodium sulfite (Na2SO3) combines with dissolved oxygen to form Na2SO4, preventing waterside corrosion.
Sodium sulfite is added to the feedwater system to protect deaerator, feedwater lines, and feedwater pumps, as well as the boiler.
Sulfite residual test procedure involves:
- Taking a representative boiler water sample protected from atmospheric oxygen.
- Measuring a 50 ml sample and adding acid starch indicator.
- Titration with potassium iodide-iodate solution.
- Recording the volume of titrant used and multiplying by 20 to find ppm of excess sodium sulfite.
Operator response to sulfite residual test:
- Adjusting sodium sulfite feed pump setting to maintain 20-60 ppm range for operating boilers and up to 80 ppm for boilers in wet layup.
- Reducing sulfite addition to stabilize concentration within the control range.
- Increasing sulfite feed to address low sulfite residual and prevent pitting corrosion.

Phosphate Control

Sodium phosphate is added directly into the boiler to prevent scale formation by reacting with calcium and magnesium ions, forming precipitates blown off from the boiler.
Phosphate residual is maintained, usually in the range of 20-60 ppm.
Residual phosphate test procedure involves:
- Taking a cooled and filtered boiler water sample.
- Using an electronic meter or color comparison against a standard.
Operator response to residual phosphate test:
- Reducing or halting phosphate feed to the boiler if excessively high, causing foaming and carryover.
- Increasing phosphate feed rate if excessively low, causing scale formation.

Water Treatment Log

Recording test results on the water treatment log sheet, including each piece of equipment in the plant and prescribed control ranges.
Comparing latest results with previous tests and taking specific action based on test results.

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