IE47613B1 - Composition and method for inhibiting corrosion in steam condensate systems - Google Patents
Composition and method for inhibiting corrosion in steam condensate systemsInfo
- Publication number
- IE47613B1 IE47613B1 IE2443/78A IE244378A IE47613B1 IE 47613 B1 IE47613 B1 IE 47613B1 IE 2443/78 A IE2443/78 A IE 2443/78A IE 244378 A IE244378 A IE 244378A IE 47613 B1 IE47613 B1 IE 47613B1
- Authority
- IE
- Ireland
- Prior art keywords
- corrosion
- steam condensate
- composition
- hydrazine
- amine
- Prior art date
Links
- 238000005260 corrosion Methods 0.000 title claims abstract description 28
- 230000007797 corrosion Effects 0.000 title claims abstract description 28
- 239000000203 mixture Substances 0.000 title claims description 10
- 230000002401 inhibitory effect Effects 0.000 title claims 8
- 238000000034 method Methods 0.000 title claims 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims abstract description 30
- FAXDZWQIWUSWJH-UHFFFAOYSA-N 3-methoxypropan-1-amine Chemical compound COCCCN FAXDZWQIWUSWJH-UHFFFAOYSA-N 0.000 claims abstract description 12
- 150000001412 amines Chemical class 0.000 abstract description 24
- 230000003472 neutralizing effect Effects 0.000 abstract description 13
- 239000007787 solid Substances 0.000 abstract description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 15
- YNAVUWVOSKDBBP-UHFFFAOYSA-N Morpholine Chemical compound C1COCCN1 YNAVUWVOSKDBBP-UHFFFAOYSA-N 0.000 description 14
- PAFZNILMFXTMIY-UHFFFAOYSA-N cyclohexylamine Chemical compound NC1CCCCC1 PAFZNILMFXTMIY-UHFFFAOYSA-N 0.000 description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 10
- 239000001301 oxygen Substances 0.000 description 10
- 229910052760 oxygen Inorganic materials 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- 239000001257 hydrogen Substances 0.000 description 8
- 229910052739 hydrogen Inorganic materials 0.000 description 8
- 229910002092 carbon dioxide Inorganic materials 0.000 description 7
- 239000001569 carbon dioxide Substances 0.000 description 7
- 229910052742 iron Inorganic materials 0.000 description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- 239000003112 inhibitor Substances 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 239000012267 brine Substances 0.000 description 5
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 5
- -1 hydrogen ions Chemical class 0.000 description 4
- 230000005764 inhibitory process Effects 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- BFSVOASYOCHEOV-UHFFFAOYSA-N 2-diethylaminoethanol Chemical compound CCN(CC)CCO BFSVOASYOCHEOV-UHFFFAOYSA-N 0.000 description 2
- CBTVGIZVANVGBH-UHFFFAOYSA-N aminomethyl propanol Chemical compound CC(C)(N)CO CBTVGIZVANVGBH-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N EtOH Substances CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- HPNMFZURTQLUMO-UHFFFAOYSA-N diethylamine Chemical compound CCNCC HPNMFZURTQLUMO-UHFFFAOYSA-N 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 238000013022 venting Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
- C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
Use of methoxypropylamine as a neutralizing amine in combination with hydrazine to prevent corrosion in steam condensate systems or in other low solids aqueous systems.
Description
This invention relates to corrosion control in steam condensate systems and other aqueous systems in which the mineral content is relatively low.
More particularly, this invention relates to the use of methoxypropylamine in combination with hydrazine to control corrosion in steam condensate systems or in other low solids aqueous systems.
Condensate corrosion protection is becoming an in10 creasingly important aspect of plant operation. In these energy-conscious -times, an increase in the quantity and quality of condensate will result in water and heat
- savings for the total boiler system.
Historically, the action of distilled gases such as oxygen and carbon dioxide have been two of the main factors that lead to condensate corrosion.
In order to understand the role of oxygen and carbon dioxide in corrosion, one must understand the electrochemical nature of corrosion. Pure water has very little effect on pure .iron, but this situation is seldom encountered. Under most conditions, there is a tendency for iron to dissolve in water, and two electrons are released for each atom that dissolves. These electrons are transferred to hydrogen ions present in water, and the ions are reduced to elemental gaseous hydrogen. All action ceases at this point if the hydrogen remains on the surface of the metal since a protective coating is formed that interferes with the passage of electrons. However, any agent which increases the number of hydrogen ions present in the water, or which will cause the removal of the protective film, serves to increase the rate of corrosion.
When carbon dioxide dissolves, it reacts with water to form carbonic acid, which supplies additional active hydrogen to the system. Iron displaces the hydrogen from this acid. When oxygen is also present in the water, a two-fold reaction takes place. Some molecules of oxygen combine with the . displaced hydrogen and thus exposes the metal to fresh attack. Other oxygen molecules combine with iron ions to form insoluble rust compounds.
A greater corroding influence than the mere dissolving tendency of iron is the existence of a heterogeneous surface in commercial iron and steel due to the presence of surface imperfections which tend to form couples with the adjacent base metal.
Electrons are released from the anodes of these couples to the hydrogen ions at the adjacent cathodic surface, thus increasing the corroding area and accelerating the rate of corrosion.
The first product of corrosion may be converted to ferric oxide, which is only loosely adherent and aggravates corrosion by blocking off areas to oxygen access. These areas become anodic and iron oxide couples are set up. The iron under the oxide deposit then dissolves, and pitting develops. Carbon dioxide attack results in thinning or grooving of the metal.
For those systems that will permit it, filming amines will give condensate corrosion protection against both oxygen and carbon dioxide. However, many idustrial systems cannot tolerate filming amines and must use neutralizing amines.
The ideal neutralizing amine should have the following characteristics:
1. The distribution ratio should be high enough so that a considerable amount of the neutralizing amine fed to the boiler will end up in the condensate. This will reduce the loss of neutralizing amine via blowdown.
2. The distribution ratio should not be too high in order to keep losses due to aeration and venting to a minimum. The distribution ratio is the ratio of the amount of amine in the vapor phase to that in the liquid phase.
3. The basicity value should be moderately high or very high so that the amine will efficiently neutralize all carbon dioxide that it encounters.
4. The neutralizing amine should have sufficient hydrolytic-thermal stability so that it will not break down to ammonia and other compounds in the boiler or in superheated or saturated steam.
. The neutralizing amine should be a watersoluble liquid for feeding convenience.
Neutralizing amines such as cyclohexylamine and morpholine have been used but they have several disadvantages. For example, cyclohexylamine has a high distribution ratio and accordingly, substantial cyclohexylamine escapes the system through the deaerator vent. Morpholine, on the other hand, has a low basicity value which means that more morpholine is required to attain high pH's in the condensate system and it also has a very low distribution ratio which means that substantial amounts are lost via blowdown.
SUMMARY OF THE INVENTION
The neutralizing amine of this invention overcomes the above-mentioned disadvantages of cyclohexylamine and morpholine. Methoxypropylamine has a very desirable distribution ratio and a fairly high basicity value.
Methoxypropylamine may be used alone or in combination with an oxygen corrosion inhibitor such as hydrazine. In use, concentrations of 0.1 to 1000 mg/1, and preferably 1 to 100 mg/1, should be maintained in the steam condensate system. When used in combination with hydrazine or another oxygen corrosion inhibitor, the composition should contain on an active basis from about 17« to about 99% methoxypropylamine and from about 0.1% tp.about 50%, preferably about 1% to about 15%, of the oxygen corrosion inhibitor. The compositions of this invention may be fed to the steam condensate system being treated by conventional liquid feeding means or may be fed to the boiler feedwater or directly to the steam supply lines.
The following examples will illustrate the use of methoxypropylamine, alone and in combination with hydrazine, as a steam condensate corrosion inhibitor in accordance with the teachings of this invention.
EXAMPLE 1
Distribution ratios of a number of neutralizing amines were calculated by preparing solutions of each amine having a concentration of 100 mg/1 and adding 500 ml of this solution to a brine pot which is slowly and uniformly heated so that 100 ml of distillate is produced every 40 minutes. Additional solution is manually introduced to the brine pot every 5 to 10 minutes to maintain the brine pot solution at the 500 ml mark. Each 100 ml aliquot of distillate is collected and pH determined until constant pH is attained for three successive aliquots. This is taken to represent the establishment of equilibrium conditions. At equilibrium, the brine and the final 100 mis are analyzed by gas chromatography to determine the amount of amine in each and the Distribution Ratio (D.R.) calculated by the following formula:
η r » Amine Concentration in Final 100 mis u' ' Amine Concentration in Brine
Similarly, the basicity value (K^) or measure of the amine's ability to react with carbon dioxide is calculated in accordance with the formula:
*b [BH+] [OH-]
-[b‘1 wherein [BH+], [OH-] and [BeJ are defined as:
[BH+] = concentration of dissociated amine [OH-] » hydroxide concentration £Be] = concentration of free, undissociated amine
The results of these tests and calculations are set forth in Table I.
Table I
Amine Properties
Molecular Weight «h Distribution Ratio Cyclohexylamine 99 153 x 10“6 3.8 Morpholine 87 2.4 x 10° 0.4 Diethylaraino- ethanol 117 52 χ IO’6 2.7 2-amino,2-methylpropanol 89 40 x 10‘6 0.3 Methoxypropyl- amine 89 130 x IO'6 1.0 Hydrazine 32 1.7 χ 10-6 ...
EXAMPLE 2
The hydrolytic-thermal stability of various neutralizing amines is measured by a test in which the neutralizing amine at a concentration of 1000 mg/1 is autoclaved for 24 hours at 41 bar (600 psi) at 254°C (489°F) and the final concentration of ammonia measured.
The results of this test are set forth in Table IX.
Table II
Amine mg/1 NH3
Methoxypropylamine <1.0
Morpholine 1.6
Cyclohexylamine 3.3
Diethylaminoethanol* 2.4
Aminomethylpropanol 124.0 *Diethylaminoethanol breaks down appreciably to diethylamine.
EXAMPLE 3
A condensate test system is used to evaluate neutralizing amines. This system comprises a boiler capable of producing 45 kilograms/hour of a steam at pressure of 13 ,7'bar (200 psi), pumps and metering devices to control the composition of the make-up water to the boiler, and cooling coils with temperature control means to condense the steam. The condensate is recirculated through a test loop where metal coupons and corrosometer probes evaluate the corrosion rate.
The test water is distilled water containing <1 mg/1 SO^, <1 mg/1 Cl, <1 mg/1 Si02 and 10 mg/1 C02Table III sets forth the results of corrosion tests in this system.
Table III
Inhibitor pH ' Concen- tration Corrosion Rate % Reduction from Control Control 0 0% Cyclohexylamine 8.5 37.5 mg/1 48% Morpholine 8.5 152 mg/1 73% Methoxypropylamine 8.5 106 mg/1 75% EXAMPLE 4 The condensate test : system of EXAMPLE 3 was used to demonstrate the effect of the addition of
hydrazine to methoxypropylamine in the inhibition of corrosion.
Table IV
Inhibitor eS Amount of Inhibition In System Inhibition Inhibition per ppm of Availabe Product Control — 0% 0.00% MPA 8.5 106 ppm 75% 0.71% 7% Hydrazine/ 93% MPA 8.5 61 ppm 83% 1.36% 15% Hydrazine/ 85% MPA 8.5 61 ppm 71% 1.16% Hydrazine 8.5 22 ppm 19% 0.86% 1% Hydrazine/ 99% MPA 8.5 49.5 ppm 55% 1.11%
*MPA - Methoxypropylamine
Claims (7)
1. A steam condensate corrosion inhibiting composition consisting essentially of methoxypropylamine and hydrazine.
2. A steam condensate corrosion inhibiting composition of Claim 1 which contains from 1 to 157. by weight hydrazine.
3. A method of inhibiting corrosion in steam condensate systems which comprises maintaining an effective 10 amount of a composition consisting essentially of methoxypropylamine and hydrazine.
4. A method of inhibiting corrosion in steam condensate systems as in Claim 3 wherein a concentration of at least 1.0 mg/1 of said composition is maintained. 15
5. A method of inhibiting corrosion in steam condensate systems as in Claim 3 wherein the composition contains from 1 to 15% by weight hydrazine.
6. A steam condensate corrosion inhibiting composition substantially as hereinbefore described and exemplified. 2o
7. A method of inhibiting corrosion in steam condensate systems substantially as hereinbefore described and exemplified.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US85934277A | 1977-12-12 | 1977-12-12 | |
| US90833478A | 1978-05-22 | 1978-05-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IE782443L IE782443L (en) | 1979-06-12 |
| IE47613B1 true IE47613B1 (en) | 1984-05-02 |
Family
ID=27127515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE2443/78A IE47613B1 (en) | 1977-12-12 | 1978-12-11 | Composition and method for inhibiting corrosion in steam condensate systems |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0002634B1 (en) |
| JP (1) | JPS5492535A (en) |
| AU (1) | AU521299B2 (en) |
| CA (1) | CA1105695A (en) |
| DE (1) | DE2860673D1 (en) |
| DK (1) | DK152766C (en) |
| IE (1) | IE47613B1 (en) |
| IT (1) | IT1107785B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4350606A (en) * | 1980-10-03 | 1982-09-21 | Dearborn Chemical Company | Composition and method for inhibiting corrosion |
| US4557835A (en) * | 1983-09-19 | 1985-12-10 | Westinghouse Electric Corp. | Process for removal of dissolved oxygen from steam generation systems |
| US5641396A (en) * | 1995-09-18 | 1997-06-24 | Nalco/Exxon Energy Chemicals L. P. | Use of 2-amino-1-methoxypropane as a neutralizing amine in refinery processes |
| JP5034483B2 (en) * | 2006-12-19 | 2012-09-26 | 栗田工業株式会社 | Anticorrosive for reducing erosion and corrosion |
| JP5691134B2 (en) * | 2009-03-31 | 2015-04-01 | 栗田工業株式会社 | How to treat boilers that are not operating |
| JP6215511B2 (en) * | 2010-07-16 | 2017-10-18 | 栗田工業株式会社 | Anticorrosive for boiler |
| CN216873443U (en) | 2019-01-04 | 2022-07-01 | 恩格特公司 | Precisely aligned assembly |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2793944A (en) * | 1951-08-30 | 1957-05-28 | Universal Oil Prod Co | Stabilization of organic compounds |
| LU36675A1 (en) * | 1957-12-19 | |||
| US3728281A (en) * | 1970-04-02 | 1973-04-17 | Fisons Ltd | Corrosion inhibiting composition containing hydrazine and a pyrazolidone or an aminophenol |
| US3983048A (en) * | 1972-12-26 | 1976-09-28 | Olin Corporation | Composition for accelerating oxygen removal comprised of a mixture of aqueous hydrazine and an aryl amine compound |
| US4062764A (en) * | 1976-07-28 | 1977-12-13 | Nalco Chemical Company | Method for neutralizing acidic components in petroleum refining units using an alkoxyalkylamine |
-
1978
- 1978-10-31 CA CA315,596A patent/CA1105695A/en not_active Expired
- 1978-12-04 EP EP78400209A patent/EP0002634B1/en not_active Expired
- 1978-12-04 DE DE7878400209T patent/DE2860673D1/en not_active Expired
- 1978-12-05 AU AU42203/78A patent/AU521299B2/en not_active Expired
- 1978-12-11 DK DK556378A patent/DK152766C/en not_active IP Right Cessation
- 1978-12-11 IE IE2443/78A patent/IE47613B1/en not_active IP Right Cessation
- 1978-12-12 JP JP15277978A patent/JPS5492535A/en active Granted
- 1978-12-12 IT IT52260/78A patent/IT1107785B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5492535A (en) | 1979-07-21 |
| JPS6140758B2 (en) | 1986-09-10 |
| EP0002634B1 (en) | 1981-04-29 |
| DK556378A (en) | 1979-06-13 |
| DK152766B (en) | 1988-05-09 |
| EP0002634A1 (en) | 1979-06-27 |
| AU4220378A (en) | 1979-06-21 |
| CA1105695A (en) | 1981-07-28 |
| DE2860673D1 (en) | 1981-08-06 |
| AU521299B2 (en) | 1982-03-25 |
| DK152766C (en) | 1988-10-03 |
| IT1107785B (en) | 1985-11-25 |
| IT7852260A0 (en) | 1978-12-12 |
| IE782443L (en) | 1979-06-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MM4A | Patent lapsed |