CA1074552A - Pyrophosphate-zinc corrosion - Google Patents
Pyrophosphate-zinc corrosionInfo
- Publication number
- CA1074552A CA1074552A CA280,348A CA280348A CA1074552A CA 1074552 A CA1074552 A CA 1074552A CA 280348 A CA280348 A CA 280348A CA 1074552 A CA1074552 A CA 1074552A
- Authority
- CA
- Canada
- Prior art keywords
- pyrophosphate
- zinc
- corrosion
- copper
- systems
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000005260 corrosion Methods 0.000 title claims abstract description 35
- 230000007797 corrosion Effects 0.000 title claims abstract description 35
- 239000011701 zinc Substances 0.000 title claims abstract description 20
- 229910052725 zinc Inorganic materials 0.000 title claims abstract description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 10
- 229910052751 metal Inorganic materials 0.000 claims abstract description 5
- 239000002184 metal Substances 0.000 claims abstract description 5
- 230000002401 inhibitory effect Effects 0.000 claims abstract description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 12
- XPPKVPWEQAFLFU-UHFFFAOYSA-J diphosphate(4-) Chemical compound [O-]P([O-])(=O)OP([O-])([O-])=O XPPKVPWEQAFLFU-UHFFFAOYSA-J 0.000 claims description 12
- 235000011180 diphosphates Nutrition 0.000 claims description 12
- 229940048084 pyrophosphate Drugs 0.000 claims description 12
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 claims description 4
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 2
- 229940098424 potassium pyrophosphate Drugs 0.000 claims description 2
- FQENQNTWSFEDLI-UHFFFAOYSA-J sodium diphosphate Chemical group [Na+].[Na+].[Na+].[Na+].[O-]P([O-])(=O)OP([O-])([O-])=O FQENQNTWSFEDLI-UHFFFAOYSA-J 0.000 claims description 2
- 229940048086 sodium pyrophosphate Drugs 0.000 claims description 2
- VKFFEYLSKIYTSJ-UHFFFAOYSA-N tetraazanium;phosphonato phosphate Chemical group [NH4+].[NH4+].[NH4+].[NH4+].[O-]P([O-])(=O)OP([O-])([O-])=O VKFFEYLSKIYTSJ-UHFFFAOYSA-N 0.000 claims description 2
- RYCLIXPGLDDLTM-UHFFFAOYSA-J tetrapotassium;phosphonato phosphate Chemical group [K+].[K+].[K+].[K+].[O-]P([O-])(=O)OP([O-])([O-])=O RYCLIXPGLDDLTM-UHFFFAOYSA-J 0.000 claims description 2
- 235000019818 tetrasodium diphosphate Nutrition 0.000 claims description 2
- 239000003112 inhibitor Substances 0.000 abstract description 4
- 239000000203 mixture Substances 0.000 abstract description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 19
- 229910052802 copper Inorganic materials 0.000 description 19
- 239000010949 copper Substances 0.000 description 19
- 238000011282 treatment Methods 0.000 description 12
- 238000012360 testing method Methods 0.000 description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 3
- 150000003751 zinc Chemical class 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 229910000389 calcium phosphate Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910000398 iron phosphate Inorganic materials 0.000 description 2
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000003643 water by type Substances 0.000 description 2
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 description 2
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- 229920000388 Polyphosphate Polymers 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- IYRDVAUFQZOLSB-UHFFFAOYSA-N copper iron Chemical compound [Fe].[Cu] IYRDVAUFQZOLSB-UHFFFAOYSA-N 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000008397 galvanized steel Substances 0.000 description 1
- 239000008235 industrial water Substances 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 239000001205 polyphosphate Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical class [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- 235000005074 zinc chloride Nutrition 0.000 description 1
- 239000011592 zinc chloride Substances 0.000 description 1
- OMSYGYSPFZQFFP-UHFFFAOYSA-J zinc pyrophosphate Chemical compound [Zn+2].[Zn+2].[O-]P([O-])(=O)OP([O-])([O-])=O OMSYGYSPFZQFFP-UHFFFAOYSA-J 0.000 description 1
- NWONKYPBYAMBJT-UHFFFAOYSA-L zinc sulfate Chemical compound [Zn+2].[O-]S([O-])(=O)=O NWONKYPBYAMBJT-UHFFFAOYSA-L 0.000 description 1
- 229960001763 zinc sulfate Drugs 0.000 description 1
- 229910000368 zinc sulfate Inorganic materials 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
- C23F11/18—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 using inorganic inhibitors
- C23F11/187—Mixtures of inorganic inhibitors
- C23F11/188—Mixtures of inorganic inhibitors containing phosphates
Landscapes
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
Abstract
In the United States Patent Office APPLICATION OF JAMES E. SCOTT, Jr.
FOR PYROPHOSPHATE-ZINC CORROSION INHIBITOR
ABSTRACT
A method for inhibiting metal corrosion in once-through water systems entailing the use of a pyrophosphate-zinc composition.
FOR PYROPHOSPHATE-ZINC CORROSION INHIBITOR
ABSTRACT
A method for inhibiting metal corrosion in once-through water systems entailing the use of a pyrophosphate-zinc composition.
Description
~07455Z
BACKGROUND
The prevention of corrosion in once-through water systems has long been of great concern to both the private and the public sectors. These once-through systems include municipal water systems and industrial once-through water cooling systems.
In the past, in municipal water systems, corrosion inhibition has been directed toward the protection of mild steel, galvanized steel and cast iron found in these systems. Now that copper piping and fittings are in-creasingly being used in homes and at other points in the municipal water sys-tem, it ~ecomes important to deal with potential copper corrosion problems.This is an especially important concern in view of environmental regulations shortly to come into effect.
According to current municipal water testing regulationsl the metal ion content of municipal water systems is measured at points short of the delivery location ~i.e. at fire hydrants). Since copper piping or fittings are generally not present in the system prior to or at these points, present steel and iron corrosion treatments suffice to prevent corrosion. However, under new regulations which will soon come into effect, municipal water test-ing will be carried out at the delivery site (i.e. the home tap). When test-2Q ing is carried out at this point, undesirably higher copper levels will beencountered unless the water is pretreated with a copper corrosion inhibitor such as the treatment described herein. Thus, the present invention becomes especially important.
In addition to its use in municipal water systems, copper is found in industrial water systems at such points as the cast copper fittings into ~Xich ~lack iron pipings may be fitted. At these points, corrosion of the copper fittings may be a problem. In addition, there is a likelihood of cor-rosion due to galvanic coupling at the point of interconnection.
Copper as us-ed herein also includes alloys of copper such as brass and admiralt~ metal.
107~552 Typical corrosion inhibitors employed in once-through water systems such as those described above have included sodium hexa-metaphosphate and zinc salt-polyphosphate combinations. These treatments have been used to prevent steel ~md iron corrosion, but they have not been used to prevent copper cor-rosion. Indeed, the most common treatment - sodium hexametaphosphate - will not prevent copper corrosion and may, in some cases, increase the corrosion rate.
I have now discovered a particular polyphsphate composition which ofers important advantages over polyphosphate-zinc compositions generally as a corrosion inhibitor and which has outstanding ability to prevent or reduce copper and mild steel corrosion rates.
OBJECTS
It is an object of the present invention to provide to the art a practical means for preventing or reducing copper corrosion in once-through water systems. It is a further object of the present invention to provide a method of inhibiting copper corrosion which is especially well adapted to the treatment of municipal water systems.
Another object of the present invention is to teach a method for reducing galvanic corrosion.
Yet another object of the present invention is to provide a method for reducing corrosion in mild steel.
Other objects will appear hereinafter.
THE IN~ENTION
The invention entails a method for inhibiting metal corrosion in once-through water systems by maintaining in the water used in these systems a specified level of pyrophosphate-zinc composition. The level of pyrophos-phate which should be maintained should range from 0.1 - 20 ppm by weight; the level of zinc maintained will range from 0.01 - 10 ppm by weight. In municipal ~ater systems, the pyrophosphate concentration should not exceed 10 and most preferably will lie within the range 0.1 - 0.9 ppm. In such municipal systems, the zinc concentration (measured as zinc) should not exceed 5 ppm and most preferably will lie within the range 0.04 - 0.3 ppm.
When I refer to pyrophosphate, I intend to include potassium pyro-phosphate, sodium pyrophosphate and ammonium pyrophosphate.
While the zinc concentrations discussed above refer to zinc metal, the zinc will be introduced in the form of a zinc salt. Typical zinc salts useful in the present application include zinc sulfate, zinc chloride and zinc nitrate. In practice, of course, any form of a soluble zinc salt will suffice.
The dosages described above should be continuously maintained in the once-through water. However, in some applications, it will be acceptable to run the systems without treatment for recurring limited periods. Also, when treating new systems, it is best to use an initial high dose followed by the lower continuous dose described above. By high initial dose, I mean 2 or 3 times the lower continuous dosage. The high initial dose should be maintained for at least 1 hour and preferably will be continued for a period of 12 - 24 hours.
EXAMPLES
Example 1 The test described in this example was carried out on a blast furnace once-through cooling water system. A test unit designed to measure corrosion was installed on the blast furnace in such a way that blast furnace discharge water could be c rculated past test coupons.
The corro.siveness to copper of the blast furnace discharge water before treatment was compared to its corrosiveness after treatment. Dosages were within the ranges of Claim 1. The results obtained indicated that the rate of copper corrosion was reduced by 84%.
In addition to the coupon testing, galvanic corrosion was monitored by running the discharge water through interconnected copper and mild steel sample tubes. Although there was some evidence of galvanic corrosion between 3Q the copper and mild steel for both treated and untreated discharge water, the ~07455Z
tube section from the treated system contained lesser deposits and showed less corrosion than did the tube from the untreated system.
In another test run in which galvanic corrosion rates were evalu-ated, direct iron-copper couples were prepared and incorporated in the test unit. In the first run, galvanic attack was noted on the untreated tubes; no galvanic attack was found on the treated tubes. In a second run, slight gal-vanic attack was found on both tubes. It is believed that longer test periods ~ould conclusively demonstrate significant reduction of galvanic attack in the treated system.
Example 2 A test may be carried out to show synergism between the pyrophosphate and the zinc. In this example, a copper *es~ sample may be subject to a once-through water system which causes corrosion of 10 mils per year. If, now, a pyrophosphate dosage which would reduce the corrosion to 5 mils per year is used in combination with a zinc treatment which would also reduce the corrosion to 5 mils per year, it would be expected that the pyrophosphate plus the zinc would result in corrosion of 2 mils per year. It will be found however, that the zinc-pyrophosphate combination will result in a corrosion rate of only 1 mil per year.
Example 3 This test can be carried out to demonstrate an advantage of pyro-phosphate-zinc over the traditional orthophosphate-zinc treatment: the ortho-phosphate treatment is useful only in fairly soft waters which are not severe-ly alkaline.
Thus, if once-through waters are adjusted to pH 8.0 or higher and treated with orthophosphates, it will be found that calcium phosphate and iron phosphate precipitate out. In actual industrial once-through systems, these precipitates will interfere with water flow.
If water adjusted to pH 8.0 or higher is treated with pyrophosphate-zinc, neither calcium or iron phosphate will form. Hence, the pyrophosphate treatment is useful at a far wider p~ range than the orthophosphate.
BACKGROUND
The prevention of corrosion in once-through water systems has long been of great concern to both the private and the public sectors. These once-through systems include municipal water systems and industrial once-through water cooling systems.
In the past, in municipal water systems, corrosion inhibition has been directed toward the protection of mild steel, galvanized steel and cast iron found in these systems. Now that copper piping and fittings are in-creasingly being used in homes and at other points in the municipal water sys-tem, it ~ecomes important to deal with potential copper corrosion problems.This is an especially important concern in view of environmental regulations shortly to come into effect.
According to current municipal water testing regulationsl the metal ion content of municipal water systems is measured at points short of the delivery location ~i.e. at fire hydrants). Since copper piping or fittings are generally not present in the system prior to or at these points, present steel and iron corrosion treatments suffice to prevent corrosion. However, under new regulations which will soon come into effect, municipal water test-ing will be carried out at the delivery site (i.e. the home tap). When test-2Q ing is carried out at this point, undesirably higher copper levels will beencountered unless the water is pretreated with a copper corrosion inhibitor such as the treatment described herein. Thus, the present invention becomes especially important.
In addition to its use in municipal water systems, copper is found in industrial water systems at such points as the cast copper fittings into ~Xich ~lack iron pipings may be fitted. At these points, corrosion of the copper fittings may be a problem. In addition, there is a likelihood of cor-rosion due to galvanic coupling at the point of interconnection.
Copper as us-ed herein also includes alloys of copper such as brass and admiralt~ metal.
107~552 Typical corrosion inhibitors employed in once-through water systems such as those described above have included sodium hexa-metaphosphate and zinc salt-polyphosphate combinations. These treatments have been used to prevent steel ~md iron corrosion, but they have not been used to prevent copper cor-rosion. Indeed, the most common treatment - sodium hexametaphosphate - will not prevent copper corrosion and may, in some cases, increase the corrosion rate.
I have now discovered a particular polyphsphate composition which ofers important advantages over polyphosphate-zinc compositions generally as a corrosion inhibitor and which has outstanding ability to prevent or reduce copper and mild steel corrosion rates.
OBJECTS
It is an object of the present invention to provide to the art a practical means for preventing or reducing copper corrosion in once-through water systems. It is a further object of the present invention to provide a method of inhibiting copper corrosion which is especially well adapted to the treatment of municipal water systems.
Another object of the present invention is to teach a method for reducing galvanic corrosion.
Yet another object of the present invention is to provide a method for reducing corrosion in mild steel.
Other objects will appear hereinafter.
THE IN~ENTION
The invention entails a method for inhibiting metal corrosion in once-through water systems by maintaining in the water used in these systems a specified level of pyrophosphate-zinc composition. The level of pyrophos-phate which should be maintained should range from 0.1 - 20 ppm by weight; the level of zinc maintained will range from 0.01 - 10 ppm by weight. In municipal ~ater systems, the pyrophosphate concentration should not exceed 10 and most preferably will lie within the range 0.1 - 0.9 ppm. In such municipal systems, the zinc concentration (measured as zinc) should not exceed 5 ppm and most preferably will lie within the range 0.04 - 0.3 ppm.
When I refer to pyrophosphate, I intend to include potassium pyro-phosphate, sodium pyrophosphate and ammonium pyrophosphate.
While the zinc concentrations discussed above refer to zinc metal, the zinc will be introduced in the form of a zinc salt. Typical zinc salts useful in the present application include zinc sulfate, zinc chloride and zinc nitrate. In practice, of course, any form of a soluble zinc salt will suffice.
The dosages described above should be continuously maintained in the once-through water. However, in some applications, it will be acceptable to run the systems without treatment for recurring limited periods. Also, when treating new systems, it is best to use an initial high dose followed by the lower continuous dose described above. By high initial dose, I mean 2 or 3 times the lower continuous dosage. The high initial dose should be maintained for at least 1 hour and preferably will be continued for a period of 12 - 24 hours.
EXAMPLES
Example 1 The test described in this example was carried out on a blast furnace once-through cooling water system. A test unit designed to measure corrosion was installed on the blast furnace in such a way that blast furnace discharge water could be c rculated past test coupons.
The corro.siveness to copper of the blast furnace discharge water before treatment was compared to its corrosiveness after treatment. Dosages were within the ranges of Claim 1. The results obtained indicated that the rate of copper corrosion was reduced by 84%.
In addition to the coupon testing, galvanic corrosion was monitored by running the discharge water through interconnected copper and mild steel sample tubes. Although there was some evidence of galvanic corrosion between 3Q the copper and mild steel for both treated and untreated discharge water, the ~07455Z
tube section from the treated system contained lesser deposits and showed less corrosion than did the tube from the untreated system.
In another test run in which galvanic corrosion rates were evalu-ated, direct iron-copper couples were prepared and incorporated in the test unit. In the first run, galvanic attack was noted on the untreated tubes; no galvanic attack was found on the treated tubes. In a second run, slight gal-vanic attack was found on both tubes. It is believed that longer test periods ~ould conclusively demonstrate significant reduction of galvanic attack in the treated system.
Example 2 A test may be carried out to show synergism between the pyrophosphate and the zinc. In this example, a copper *es~ sample may be subject to a once-through water system which causes corrosion of 10 mils per year. If, now, a pyrophosphate dosage which would reduce the corrosion to 5 mils per year is used in combination with a zinc treatment which would also reduce the corrosion to 5 mils per year, it would be expected that the pyrophosphate plus the zinc would result in corrosion of 2 mils per year. It will be found however, that the zinc-pyrophosphate combination will result in a corrosion rate of only 1 mil per year.
Example 3 This test can be carried out to demonstrate an advantage of pyro-phosphate-zinc over the traditional orthophosphate-zinc treatment: the ortho-phosphate treatment is useful only in fairly soft waters which are not severe-ly alkaline.
Thus, if once-through waters are adjusted to pH 8.0 or higher and treated with orthophosphates, it will be found that calcium phosphate and iron phosphate precipitate out. In actual industrial once-through systems, these precipitates will interfere with water flow.
If water adjusted to pH 8.0 or higher is treated with pyrophosphate-zinc, neither calcium or iron phosphate will form. Hence, the pyrophosphate treatment is useful at a far wider p~ range than the orthophosphate.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for inhibiting metal corrosion in once-through water systems comprising maintaining a level of 0.1 - 20 ppm by weight of pyrophosphate and 0.01 - 10 ppm by weight of zinc in the water passing through the system, said once-through systems being characterized as being at least partially composed of copper alloys.
2. The method of Claim 1 wherein the pyrophosphate is potassium pyro-phosphate.
3. The method of Claim 1 wherein the pyrophosphate is sodium pyrophos-phate.
4. The method of Claim 1 wherein the pyrophosphate is present at a level of 0.1 - 0.9 ppm and the zinc is present at a level of 0.04 - 0.3 ppm.
5. The method of Claim 1 wherein the pyrophosphate is ammonium pyrophos-phate.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/711,756 US4089651A (en) | 1976-08-04 | 1976-08-04 | Pyrophosphate-zinc corrosion inhibitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1074552A true CA1074552A (en) | 1980-04-01 |
Family
ID=24859382
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA280,348A Expired CA1074552A (en) | 1976-08-04 | 1977-06-13 | Pyrophosphate-zinc corrosion |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4089651A (en) |
| CA (1) | CA1074552A (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DK231879A (en) * | 1978-06-05 | 1979-12-06 | Calgon Corp | PROCEDURE FOR CORROSION INHIBITION AND PRODUCT FOR USE IN THE PERFORMANCE OF THE PROCEDURE |
| US4301025A (en) * | 1980-02-06 | 1981-11-17 | The Dow Chemical Company | Derivatives of polyphosphoric acid partial esters |
| US4278477A (en) * | 1980-03-19 | 1981-07-14 | Amchem Products, Inc. | Metal treatment |
| US4500445A (en) * | 1982-03-10 | 1985-02-19 | Petrolite Corporation | Corrosion inhibited aqueous slurries |
| US4714597A (en) * | 1986-06-26 | 1987-12-22 | Hylsa, S.A. | Corrosion inhibitor for CO2 absorption process using alkanolamines |
| US4950449A (en) * | 1986-08-27 | 1990-08-21 | General Electric Company | Inhibition of radioactive cobalt deposition in water-cooled nuclear reactors |
| US4759900A (en) * | 1986-08-27 | 1988-07-26 | General Electric Company | Inhibition of radioactive cobalt deposition in water-cooled nuclear reactors |
| US4803007A (en) * | 1987-10-16 | 1989-02-07 | Garber Frank R | Corrosion inhibitor for salt-based deicing compositions |
| CA2049723C (en) * | 1990-08-23 | 2003-08-19 | Donald T. Ireland | Liquid anticorrosive and antiscaling deicing composition |
| US5378401A (en) * | 1992-01-31 | 1995-01-03 | Klenzoid, Inc. | Preparation of zinc polyphosphate in high PH solution |
| US5444400A (en) * | 1993-11-02 | 1995-08-22 | Hewlett-Packard Company | Logic output circuit with high transient pull-up current |
| US6126859A (en) * | 1998-11-20 | 2000-10-03 | Betzdearborn Inc. | Method and composition for corrosion and deposition inhibition in aqueous systems |
| US6391384B1 (en) | 2000-07-10 | 2002-05-21 | Carus Corporation | Method for providing a corrosion inhibiting solution |
| JP4089648B2 (en) * | 2004-03-31 | 2008-05-28 | 栗田工業株式会社 | Corrosion prevention method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3445395A (en) * | 1967-10-12 | 1969-05-20 | Wyandotte Chemicals Corp | Composition of improved water-glycol antifreeze and heat exchange media and process for manufacture of same |
| US3510436A (en) * | 1968-10-31 | 1970-05-05 | Betz Laboratories | Corrosion inhibition in water system |
| US3580855A (en) * | 1969-04-09 | 1971-05-25 | Rohm & Haas | Process for inhibition of scale and corrosion using a polyfunctional phosphated polyol ester having at least 75% primary phosphate ester groups |
| US3668132A (en) * | 1970-06-15 | 1972-06-06 | Ecodyne Corp | Composition and method |
| US3669616A (en) * | 1971-09-28 | 1972-06-13 | Virginia Chemicals Inc | Corrosion inhibiting compositions and method |
| US3887488A (en) * | 1972-03-08 | 1975-06-03 | Celanese Corp | Inhibition of corrosion in sulfuric acid solutions |
-
1976
- 1976-08-04 US US05/711,756 patent/US4089651A/en not_active Expired - Lifetime
-
1977
- 1977-06-13 CA CA280,348A patent/CA1074552A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4089651A (en) | 1978-05-16 |
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