Enviro Guard Catalyzed sodium sulfite for corrosion prevention. Generally speaking, sulfite is not present in natural water. In boiler feedwater conditioning sodium sulfite is fed to a boiler to remove dissolved oxygen and thus prevent pitting. For the reaction between sulfite and oxygen to proceed rapidly and completely, it is necessary to maintain an excess sulfite concentration at an elevated temperature.
Theoretically, 3.5 Kg of chemically pure sodium sulfite are required to remove approx 400 gram of oxygen. The efficiency of the oxygen removal is estimated at 75 per cent to allow for oxidation in contact with air, blowdown losses, etc. Therefore it is estimated that 4.5 Kg of commercial sodium sulfite are required for 450 Gram of oxygen removed (or 10 ppm sulfite per 1 ppm dissolved oxygen.)
The use of sodium sulfite as a chemical deoxygenator is economical within certain limitations imposed by the dissolved oxygen content of the feedwater. If appreciable quantities of dissolved oxygen are permitted to enter the boiler, costs will be high if sulfite is relied on as the sole means of oxygen removal. Generally, costs are balanced by removal of as much of the oxygen as feasible by mechanical means, e.g. deaerator and by using sulfite to react with the residual oxygen.
To prevent corrosion and pitting in feed lines, closed heaters and economizers, it is desirable to feed the sulfite continuously to the boiler feedwater rather than directly to the boiler feedwater rather than directly to the boiler. Reaction between sulfite and oxygen is not instantaneous and the completion of the reaction is aided by the longer contact times provided by feeding sulfite to the feedwater.
Catalyzed sodium sulfite will, however, react almost instantaneously with dissolved oxygen even at cold water temperatures. Because of this property, catalyzed sulfite has found increased use in the treatment of cooling water, process water, distribution system, etc. for preventing oxygen corrosion.
Enviro Guard Sulfite is a white granular material.
White, free flowing crystalline Odorless powder
Dose of Enviro Guard Sulfite can be controlled by this method ::: Because it readily reacts with oxygen to form sulfate, sulfite is not usually found in natural water systems. In its most common form, sodium sulfite, it is widely used as an oxygen scavenger in feedwater conditioning to prevent pitting in boilers; as a pulping or pulp-bleaching agent by the paper industry; to neutralize residual chlorine in potable water, sewage, industrial effluents, and textile process waters; and as a reducing agent in still other manufacturing processes.
Sample water over 100°F will cause a false-high reading; therefore, quickly cool to room temperature before testing. To prevent a false-low reading caused by the reaction between sulfite and ambient air or dissolved oxygen, water samples should be capped while cooling and then tested without delay. An iodometric drop test is the most popular field method for determining sodium sulfite concentrations.
Reagent packs, containing an instruction and chemicals only, may be purchased for use with buret setups. Note: Sulfide and ferrous iron cause positive interference; copper and nitrite cause negative interference.
Sulfite, Titrimetric Method(0-100ppm)
The test for sulfite is based on the colour change end point reaction. At the end point reagent combines with the indicator to form a blue color.
Apparatus Required
Buret, automatic, 25 ml - 1 ( Sample Tube, Graduated, 25 mL, plastic w/cap and white dot )
Casserole porcelain, 210 ml - 1
Cylinder, graduated, 50 ml - 1
Measuring dipper (plastic) - 1
Stirring rod, glass - 1
Chemicals Required
TK - 13 ::: RXSOL-62-5503-002
TK - 14 ::: RXSOL-62-5503-003
TK - 15 ::: RXSOL-62-5503-004 ( 1 ml =0.5 mg SO3 )
Procedure for Test
The water sample should be freshly obtained with as little contact as possible with air. Do not filter the sample, but cool it to room temperature (70 to 800F).
NOTE:
Sample must be cooled to less than 100ºF (38ºC) to prevent high test results.
Sample must be protected from air contact while cooling to prevent low test results.
1. Measure 50 ml of the water sample with the graduated cylinder . For error free result Collect water to be tested in a clean, preferably large-mouthed, bottle to overflowing. Immediately cap and cool to room temperature.
2. Add three or four drops of TK - 13 ::: RXSOL-62-5503-002 to the sample Swirl to mix. Sample should turn red.
3. Add TK - 14 ::: RXSOL-62-5503-003 Powder a dipper at a time, swirling after each dipper, until color changes from red to colorless. Add 2 more dippers. Swirl until dissolved. ( Note : Use the plastic dipper to add TK - 14 ::: RXSOL-62-5503-003 to the sample. Add only one measure at a time and stir thoroughly between each addition of TK - 14 ::: RXSOL-62-5503-003. All the particle of TK - 14 ::: RXSOL-62-5503-003 may not dissolve and this may create a slight haze in the sample. Continue to add the TK - 14 in this manner until the red color disappears. It is not necessary that the sample solution be exactly neutralized, only that the sample turn colorless. When the sample is colorless, add one additional measure of TK - 14 ::: RXSOL-62-5503-003 and stir. )
4. Add TK - 15 ::: RXSOL-62-5503-004 Reagent dropwise, swirling and counting after each drop, until color changes from colorless to a faint but permanent blue. Always hold bottle in vertical position.
This color change is taken as the endpoint. Record the ml of TK - 15 ::: RXSOL-62-5503-004 solution used.
Calculation of Results
FORMULA: ppm sulfite as SO3 = ml of TK - 15 ::: RXSOL-62-5503-004 x 500 / ml SAMPLE
Using a 50 ml sample, sulfite, in parts per million as SO3 is equal to the ml of TK - 15 ::: RXSOL-62-5503-004 required multiplied by 10.
Limitations of Test :::
This method is rapid and adaptable to field determinations. It is affected by any oxidizable substances in the water such as organic matter sulfides and nitrites. The presence of these interfering substances will cause the sulfite content obtained from this titration to by shown as a higher value than actually exists.
The use of untreated water in a boiler can cause scale buildup and corrosion. Treating the boiler water with chemicals - known as boiler feed water treatment - will increase the life of the boiler and reduce maintenance costs. Scale is formed from calcium and magnesium salts that are carried in solution in the water used in the boiler. Treatment of the boiler water by raising the pH with the addition of alkaline salts – such as sodium or potassium hydroxide – will prohibit most of the calcium and magnesium salts from precipitating and causing scale buildup in the boiler. Sodium sulfite is a constituent of some boiler feed water treatments. This constituent acts as an oxygen scavenger. The presence of oxygen in boiler water will lead to corrosion of the boiler . A chelating agent, sodium hexametaphosphate is sometimes added to boiler water to inhibit hard water salts from precipitating to form scale. Hydrochloric acid is sometimes utilized in acid boils to remove scale form the boiler.
Oxygen Control
Chemical Oxygen Scavengers. The oxygen scavengers most commonly used in boiler systems are sodium sulfite, sodium bisulfite, hydrazine, catalyzed versions of the sulfites and hydrazine, and organic oxygen scavengers, such as hydroquinone and ascorbate.
It is of critical importance to select and properly use the best chemical oxygen scavenger for a given system. Major factors that determine the best oxygen scavenger for a particular application include reaction speed, residence time in the system, operating temperature and pressure, and feedwater pH. Interferences with the scavenger/oxygen reaction, decomposition products, and reactions with metals in the system are also important factors. Other contributing factors include the use of feedwater for attemperation, the presence of economizers in the system, and the end use of the steam. Chemical oxygen scavengers should be fed to allow ample time for the scavenger/oxygen reaction to occur. The deaerator storage system and the feedwater storage tank are commonly used feed points.
In boilers operating below 1,000 psig, sodium sulfite and a concentrated liquid solution of catalyzed sodium bisulfite are the most commonly used materials for chemical deaeration due to low cost and ease of handling and testing. The oxygen scavenging property of sodium sulfite is illustrated by the following reaction:
| 2Na2SO3 | + | O2 | ® | 2Na2SO4 |
| sodium Sulfite | oxygen | sodium sulfate |
Theoretically, 7.88 ppm of chemically pure sodium sulfite is required to remove 1.0 ppm of dissolved oxygen. However, due to the use of technical grades of sodium sulfite, combined with handling and blowdown losses during normal plant operation, approximately 10 lb of sodium sulfite per pound of oxygen is usually required. The concentration of excess sulfite maintained in the feedwater or boiler water also affects the sulfite requirement.
Sodium sulfite must be fed continuously for maximum oxygen removal. Usually, the most suitable point of application is the drop leg between the deaerator and the storage compartment. Where hot process softeners are followed by hot zeolite units, an additional feed is recommended at the filter effluent of the hot process units (prior to the zeolite softeners) to protect the ion exchange resin and softener shells.
As with any oxygen scavenging reaction, many factors affect the speed of the sulfite-oxygen reaction. These factors include temperature, pH, initial concentration of oxygen scavenger, initial concentration of dissolved oxygen, and catalytic or inhibiting effects. The most important factor is temperature. As temperature increases, reaction time decreases; in general, every 18°F increase in temperature doubles reaction speed. At temperatures of 212°F and above, the reaction is rapid. Overfeed of sodium sulfite also increases reaction rate. The reaction proceeds most rapidly at pH values in the range of 8.5-10.0.
The following operational conditions necessitate the use of catalyzed sodium sulfite:
- low feedwater temperature
- incomplete mechanical deaeration
- rapid reaction required to prevent pitting in the system
- short residence time
- use of economizers
High feedwater sulfite residuals and pH values above 8.5 should be maintained in the feedwater to help protect the economizer from oxygen attack.
Some natural waters contain materials that can inhibit the oxygen/sulfite reaction. For example, trace organic materials in a surface supply used for makeup water can reduce speed of scavenger/oxygen reaction time. The same problem can occur where contaminated condensate is used as a portion of the boiler feedwater. The organic materials complex metals (natural or formulated catalysts) and prevent them from increasing the rate of reaction.
Sodium sulfite must be fed where it will not contaminate feedwater to be used for attemporation or desuperheating. This prevents the addition of solids to the steam.
At operating pressures of 1,000 psig and higher, hydrazine or organic oxygen scavengers are normally used in place of sulfite. In these applications, the increased dissolved solids contributed by sodium sulfate (the product of the sodium sulfite-oxygen reaction) can become a significant problem. Also, sulfite decomposes in high-pressure boilers to form sulfur dioxide (SO2) and hydrogen sulfide (H2S). Both of these gases can cause corrosion in the return condensate system and have been reported to contribute to stress corrosion cracking in turbines. Hydrazine has been used for years as an oxygen scavenger in high-pressure systems and other systems in which sulfite materials cannot be used. Hydrazine is a reducing agent that removes dissolved oxygen by the following reaction:
| N2H4 | + | O2 | ® | 2H2O | + | N2 |
| hydrazine | oxygen | water | nitrogen |
Because the products of this reaction are water and nitrogen, the reaction adds no solids to the boiler water. The decomposition products of hydrazine are ammonia and nitrogen. Decomposition begins at approximately 400°F and is rapid at 600°F. The alkaline ammonia does not attack steel. However, if enough ammonia and oxygen are present together, copper alloy corrosion increases. Close control of the hydrazine feed rate can limit the concentration of ammonia in the steam and minimize the danger of attack on copper-bearing alloys. The ammonia also neutralizes carbon dioxide and reduces the return line corrosion caused by carbon dioxide.
Hydrazine is a toxic material and must be handled with extreme care. Because the material is a suspected carcinogen, federally published guidelines must be followed for handling and reporting. Because pure hydrazine has a low flash point, a 35% solution with a flash point of greater than 200°F is usually used. Theoretically, 1.0 ppm of hydrazine is required to react with 1.0 ppm of dissolved oxygen. However, in practice 1.5-2.0 parts of hydrazine are required per part of oxygen.
The factors that influence the reaction time of sodium sulfite also apply to other oxygen scavengers. Rate of reaction as a function of temperature and hydrazine concentration. The reaction is also dependent upon pH (the optimum pH range is 9.0-10.0)
| Porduct Name | Enviro Guard Sulfite |
| Part Number | RXSOL-23-1304-026 |
Company Details:....
RX MARINE INTERNATIONAL
105, A wing , BSEL , TECH PARK.
VASHI ,NEW BOMBAY 400703 INDIA
Branch : Kandla, Mumbai , Chennai, Vizag, Kolkata, UAE , OMAN , CANADA and KENYA
| Phone | +91 22 20871200 - 1400 |
| Fax | +91 22 27612100 :::AOH :0091 9821214367 |
| mail@rxmarine.com | |
| Website | www.rxmraine.com |
Substances
| Formula | Na2O3S |
| Molecular weight | 126,04 g/mol |
| CAS-No | 7757-83-7 |
| EC-No. | 231-821-4 |
| Classification of the substance or mixture | Not a hazardous substance or mixture according to Regulation (EC) No 1272/2008. |
| Label elements | No hazard pictogram, no signal word, no hazard statement(s), no precautionary statement(s) required |
| Other hazards |
This substance/mixture contains no components considered to be either persistent,
bioaccumulative and toxic (PBT), or very persistent and very bioaccumulative (vPvB) at
levels of 0.1% or higher.
Ecological information:
The substance/mixture does not contain components considered to have endocrine
disrupting properties according to REACH Article 57(f) or Commission Delegated regulation
(EU) 2017/2100 or Commission Regulation (EU) 2018/605 at levels of 0.1% or higher.
Toxicological information:
The substance/mixture does not contain components considered to have endocrine
disrupting properties according to REACH Article 57(f) or Commission Delegated regulation
(EU) 2017/2100 or Commission Regulation (EU) 2018/605 at levels of 0.1% or higher.
|
Description of first aid measures
| If inhaled | After inhalation: fresh air. |
| In case of skin contact | In case of skin contact: Take off immediately all contaminated clothing. Rinse skin with water/ shower |
| In case of eye contact | After eye contact: rinse out with plenty of water. Remove contact lenses. |
| If swallowed | After swallowing: make victim drink water (two glasses at most). Consult doctor if feeling unwell. |
| Most important symptoms and effects, both acute and delayed | The most important known symptoms and effects are described in the labelling (see section 2.2) and/or in section 11 |
| Indication of any immediate medical attention and special treatment needed | No data available |
Extinguishing media
| Suitable extinguishing media | Use extinguishing measures that are appropriate to local circumstances and the surrounding environment. |
| Unsuitable extinguishing media | For this substance/mixture no limitations of extinguishing agents are given. |
| Special hazards arising from the substance or mixture |
Highly flammable liquid and vapor. Runoff to sewer may create fire or explosion hazard.
In a fire or if heated, a pressure increase will occur and the container may burst, with the
risk of a subsequent explosion. The vapor/gas is heavier than air and will spread along
the ground. Vapors may accumulate in low or confined areas or travel a considerable
distance to a source of ignition and flash back.
Highly flammable liquid and vapor. Runoff to sewer may create fire or explosion hazard.
In a fire or if heated, a pressure increase will occur and the container may burst, with the
risk of a subsequent explosion. The vapor/gas is heavier than air and will spread along
the ground. Vapors may accumulate in low or confined areas or travel a considerable
distance to a source of ignition and flash back.
Highly flammable liquid and vapor. Runoff to sewer may create fire or explosion hazard.
In a fire or if heated, a pressure increase will occur and the container may burst, with the
risk of a subsequent explosion. The vapor/gas is heavier than air and will spread along
the ground. Vapors may accumulate in low or confined areas or travel a considerable
distance to a source of ignition and flash back.
Sulfur oxides
Sodium oxides
Not combustible.
Ambient fire may liberate hazardous vapours.
|
| Advice for firefighters |
In the event of fire, wear self-contained breathing apparatus. |
| Further information |
Suppress (knock down) gases/vapors/mists with a water spray jet. Prevent fire extinguishing water from contaminating surface water or the ground water system.
spray to keep fire-exposed containers cool.Promptly isolate the scene by removing all persons from the vicinity of the incident if
there is a fire. No action shall be taken involving any personal risk or without suitable
training. Move containers from fire area if this can be done without risk. Use water
spray to keep fire-exposed containers cool.
|
| Personal precautions, protective equipment and emergency procedures |
Advice for non-emergency personnel: Avoid inhalation of dusts. Evacuate the danger area, observe emergency procedures, consult an expert.
For personal protection see section 8.
|
| Environmental precautions | Do not let product enter drains. |
| Methods and materials for containment and cleaning up | Cover drains. Collect, bind, and pump off spills. Observe possible material restrictions (see sections 7 and 10). Take up dry. Dispose of properly. Clean up affected area. Avoid generation of dusts. |
| Reference to other sections | For disposal see section 13. |
| Precautions for safe handling | For precautions see section 2.2. |
|
Conditions for safe storage, including any incompatibilities Storage conditions |
Tightly closed. Dry.
Air and moisture sensitive.
Recommended storage temperature see product label.Tightly closed.
Recommended storage temperature see product label.
|
| Specific end use(s) | Apart from the uses mentioned in section 1.2 no other specific uses are stipulated |
Control parameters
| Eye/face protection | Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU). Safety glasses |
| Skin protection |
This recommendation applies only to the product stated in the safety data sheet,
supplied by us and for the designated use. When dissolving in or mixing with other
substances and under conditions deviating from those stated in EN 16523-1 please
contact the supplier of CE-approved gloves (e.g. KCL GmbH, D-36124 Eichenzell,
Internet: www.kcl.de).
Full contact
Material: Nitrile rubber
Minimum layer thickness: 0,11 mm
Break through time: 480 min
Material tested:KCL 741 Dermatril® L
This recommendation applies only to the product stated in the safety data sheet,
supplied by us and for the designated use. When dissolving in or mixing with other
substances and under conditions deviating from those stated in EN 16523-1 please
contact the supplier of CE-approved gloves (e.g. KCL GmbH, D-36124 Eichenzell,
Internet: www.kcl.de).
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0,11 mm
Break through time: 480 min
Material tested:KCL 741 Dermatril® L
|
| Respiratory protection |
Required when dusts are generated.
Our recommendations on filtering respiratory protection are based on the following
standards: DIN EN 143, DIN 14387 and other accompanying standards relating to
the used respiratory protection system.
Recommended Filter type: Filter type P1
The entrepeneur has to ensure that maintenance, cleaning and testing of respiratory
protective devices are carried out according to the instructions of the producer.
These measures have to be properly documented.
|
| Control of environmental exposure | Do not let product enter drains.. |
Information on basic physical and chemical properties
| Physical state | Solid |
| Color | No data available |
| Odor | No data available |
| Melting point/freezing point | Decomposes before melting. |
| Initial boiling point and boiling range | Not applicable |
| Flammability (solid, gas) | The product is not flammable. |
| Upper/lower flammability or explosive limits | No data available |
| Flash point | No data available |
| Autoignition temperature | does not ignite |
| Decomposition temperature |
No data available
materials.Extremely flammable in the presence of the following materials or conditions: oxidizing
materials.
|
| pH |
9,0 - 10,5 at 126 g/l at 25 °C |
| Viscosity |
Viscosity, kinematic: No data available
Viscosity, dynamic: No data available
|
| Water solubility | 126 g/l at 20 °C - completely soluble |
| Partition coefficient: n-octanol/water | No data available |
| Vapor pressure | No data available |
| Density | 2,630 g/cm3 |
| Relative density | No data available |
| Relative vapor density | No data available |
| Particle characteristics | No data available |
| Explosive properties | Not explosive |
| Oxidizing properties | The substance or mixture is not classified as oxidizing. |
| Other safety information | No data available |
| Reactivity | No data available |
| Chemical stability | The product is chemically stable under standard ambient conditions (room temperature) |
| Possibility of hazardous reactions |
Violent reactions possible with:
nitrites
Exothermic reaction with:
Oxidizing agents
Generates dangerous gases or fumes in contact with:
acids
|
| Conditions to avoid |
Exposure to air may affect product quality. Exposure to moisture may affect product
quality.
No information available |
| Incompatible materials |
No data available
|
| Hazardous decomposition products | In the event of fire: see section 5 |
Information on toxicological effects
| Acute toxicity |
LD50 Oral - Rat - 3.560 mg/kg
LC50 Inhalation - Rat - 4 h - > 5.500 mg/m3 - dust/mist
LD50 Dermal - Rat - > 2.000 mg/kg
(OECD Test Guideline 402)
|
| Skin corrosion/irritation |
Skin - Rabbit
Result: No skin irritation
(OECD Test Guideline 404)
|
| Serious eye damage/eye irritation |
Eyes - Rabbit
Result: Mild eye irritation
(OECD Test Guideline 405)
|
| Respiratory or skin sensitization |
Prolonged or repeated exposure may cause allergic reactions in certain sensitive
individuals.
in vivo assay - Mouse
Result: Did not cause sensitization on laboratory animals.
|
| Germ cell mutagenicity | No data available |
| Carcinogenicity |
This product is or contains a component that is not classifiable as to its carcinogenicity based on its IARC, ACGIH, NTP, or EPA classification.
|
| Reproductive toxicity | No data available |
| Specific target organ toxicity - single exposure | No data available |
| Specific target organ toxicity - repeated exposure | No data available |
| Aspiration hazard | No data available |
| Toxicity | |
|
Toxicity to fish LC50 - Gambusia affinis (Mosquito fish) - 660 mg/l - 96 h
Toxicity to
fish(Chronic toxicity)
|
LC50 - Gambusia affinis (Mosquito fish) - 660 mg/l - 96 h
NOEC - Danio rerio (zebra fish) - > 316 mg/l - 34 d
(OECD Test Guideline 210)
|
| Persistence and degradability | The methods for determining biodegradability are not applicable to inorganic substances. |
| Bioaccumulative potential | No data available |
| Mobility in soil | No data available |
| Results of PBT and vPvB assessment |
This substance/mixture contains no components considered to be either persistent, bioaccumulative and toxic (PBT), or very persistent and very bioaccumulative (vPvB) at
levels of 0.1% or higher
|
|
Endocrine disrupting properties Product |
|
| Assessment | The substance/mixture does not contain components considered to have endocrine disrupting properties according to REACH Article 57(f) or Commission Delegated regulation (EU) 2017/2100 or Commission Regulation (EU) 2018/605 at levels of 0.1% or higher. |
| Other adverse effects | No data available . |
| Waste treatment Method | No data available . |
| UN number | ADR/RID: IMDG: IATA: |
| UN proper shipping name |
ADR/RID: Not dangerous goods
IMDG: Not dangerous goods
IATA: Not dangerous goods
|
| Transport hazard class(es) | ADR/RID: IMDG: IATA: |
| Packaging group | ADR/RID: IMDG: IATA: |
| Environmental hazards | ADR/RID: No IMDG: No IATA: No |
| Special precautions for user | No data available |
| Further information | Not classified as dangerous in the meaning of transport regulations. |
| Safety, health and environmental regulations/legislation specific for the substance or mixture | This material safety data sheet complies with the requirements of Regulation (EC) No. 1907/2006. |
| Other regulations | Observe work restrictions regarding maternity protection in accordance to Dir 92/85/EEC or stricter national regulations where applicable. Take note of Dir 94/33/EC on the protection of young people at work. |
| Chemical Safety Assessment | For this product a chemical safety assessment was not carried out |
| Other Information |
The information above is believed to be accurate and represents the best information currently available to us. However, we make no warranty of merchantability or any other warranty, express or implied, with respect to such information, and weassume no liability resulting from its use. Users should make their own investigations to determine the suitability of the information for their particular purposes. In no event shall be liable for any claims, losses, or damages of any third party or for lost profits or any special, indirect, incidental, consequential or exemplary damages, howsoever arising, even if Rx Marine International has been advised of the possibility of such damages. DISCLAIMER OF LIABILITY :The information in this SDS was obtained from sources which we believe are reliable. However, the information is provided without any warranty, express or implied, regarding its correctness. The conditions or methods of handling, storage, use or disposal of the product are beyond our control and may be beyond our knowledge. For this and other reasons, we do not assume responsibility and expressly disclaim liability for loss, damage or expense arising out of or in any way connected with the handling, storage, use or disposal of the product. This MSDS was prepared and is to be used only for this product. If the product is used as a component in another product, this MSDS information may not be applicable. |