Title of Invention

PROCEDURE FOR APPLYING A CORROSION PROTECTION ON A PRESSURE VESSEL AND PRESSURE VESSEL FOR FIRE EXTINGUISHING MEDIUM

Abstract

The invention relates to a process for applying an anti-corrosive coat on a pressure vessel for fire extinguishing medium, wherein the vessel, preferably in a heating oven, is heated-up to a specified temperature, a duro-plastic material is applied uniformly on the internal wall of the prezheated vessel, and after a partial cooling down and, if necessary, after an intermediate storage, a duro-plastic material is applied on its outside at low temperatures, whereupon the vessel is assembled, filled and tested. The invention based pressure vessel, preferably a fire extinguisher, has the advantage, that due to a higher tensile strength of the internal and external coat a longer working life is achieved.

Full Text

FORM 2 THE PATENT ACT 1.97 0 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION PROCEDURE FOR APPLYING A CORROSION PROTECTION ON A PRESSURE VESSEL AND PRESSURE VESSEL FOR FIRE EXTINGUISHING MEDIUM 2. APPLICANT(S) a) Name b) Nationality c) Address MINIMAX MOBILE SERVICES GMBH & CO., KG. GERMAN Company MINIMAXSTRASSE 1, D-72574 BAD URACH GERMANY 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - Process for applying a corrosion protection on a pressure vessel and pressure vessel for fire extinguishing medium The invention relates to a process for applying a corrosion protection on a pressure vessel and pressure vessel for fire extinguishing medium according to the first patent claim and a pressure vessel for fire extinguishing medium coated as per this process. The invention is applicable all over those places, where pressure vessel for fire extinguishing medium, so-called fire extinguisher, to be produced with internal and external coating, which must prove a long durability. To ensure, like fire extinguisher pressure vessel show a long durability, it is essential to coat these on their inside and outside. Traditional fire extinguisher have in the inside a coating, which should prevent, that the fire extinguishing medium attacks the wall material. The external coating of a fire extinguisher is normally red in Germany and should prevent that the external wall of the fire extinguisher corrodes or gets destroyed beforehand through mechanical stress. Since fire extinguisher must be not only available but also perform their function for many years or decades, very special requirements are to be placed on these coats. The surface finish of the coat in the inside of the fire extinguisher must be resistant as far as possible for very many years against extinguishing liquid, which can be chemically aggressive and is under pressure. Further, this coat should not tear-off due to mechanical changes of the wall caused due to impacting of the fire extinguisher. Further it must be ensured that the coat is evenly applied across the entire inner surface of the fire extinguisher, so that no weak spots emerge, due to which after many years a too thin a coated spot in the fire extinguisher corrodes. The external coat of a fire extinguisher must be resistant against aggressive media, which are in the air surrounding the fire extinguisher, wherein a tearing-off of the coat due to mechanical stress should not be possible and a resistance to temperature in specified areas must be ensured. Traditional fire extinguishers are coated inside by applying the coating material by means of a lance on the internal surface of the fire extinguisher. The coating material is a thermoplastic material, which is sprayed on the inside of the pressure vessel. The vessel can be cold during this work sequence. Electrical charging of the vessel supports a faultless coat. Also the outside of the vessel is sprayed with thermoplastic material in red color and dried thereafter. From DO 160 392 a process emerges for producing corrosion and chemical resistant protective coats on the internal surfaces of pipes and hollow bodies, wherein the coat is applied in electrostatic process. This state of technology, in which the work pieces are coated at a temperature above the melting point of the 2 coating powder by using high voltage carrying electrodes, reflect the state of technology, with which presently pressure vessels for fire extinguishing media are coated. Coatings of vessels, which were coated according to this process, have damages after passage of certain time of their usage at various spots on the coated surface especially when these have been under mechanical stress or if the coating was applied in uneven manner. These vessels must then be replaced. It is, therefore, the task of the invention to develop a process for applying a corrosion protection on a pressure vessel for fire extinguishing medium, which is easy to execute and whose working life is increased vis-a-vis traditional pressure vessels for fire extinguishing medium. This task is resolved through a process according to the characteristics of the first patent claim and through a pressure vessel according to the characteristics of the claim 11. Sub-claims reflect advantageous designs of the invention. The invention based solution provides for a process for applying a anti-corrosion protection coat on the wall of a pressure vessel for fire extinguishing medium, in which on the basis of invention a duro-plastic material is applied on the internal wall of a pre-heated vessel and after a partial cooling of the vessel a duro-plastic material is applied on its outside at lower temperature. Pressure vessel for fire extinguishing medium should mean the body of the fire extinguisher. In a first process step, the pressure vessel, preferably in a heating furnace, is heated to a pre-determined temperature. This temperature is equal to the temperature, which is necessary, for applying the planned coat. It is 250 to 300°C, advantageously for a duro-plastic material 250°C. The duro-plastic material is then applied evenly on the internal wall of the pre-heated vessel. This can happen in advantageous manner by means of a lance, with the help of which the duro-plastic material in granulated liquid form is brought from a storage tank in the inside of the lance and through this as per generally known state of technology it is sprayed on the internal wall of the pre-heated vessel. In this process it of advantage, if the vessel is rotated around its longitudinal axis. The rotation speed can be between 0.2 and 1.5 rotations per minute. Further, it is advantageous, to build-up the inner coat up to a thickness of 500 to 1,000 pm. the throughput of the lance is controlled in conjunction with the form of the internal wall. This is essential to the extent that the straight cylinder surfaces of the internal wall are provided with a same throughput of coating material, whereas the upper round portion and the bottom of the pressure vessel are to be sprayed with a different throughput. In this process it is advantageous, if the internal coat is uniformly built up across the entire internal surface. Programs for controlling the lance 3 for the internal coating are known to the technician and should not be explained at this stage. After the internal coat has been evenly applied on the wall of the pre-heated vessel, follows the cooling of the pressure vessel. According to the hardening behavior of the duro-plastic material the cooling speed of the vessel is specified. Accordingly, the vessel can be cooled during an intermediate storage, whose time is to be exactly determined. This, for example, can be 1 to 2 hours. As far as the hardening behavior of the coating material requires it, the partial cooling can, however, be regulated by circulating air. This air can cool the vessel outside or if necessary, if required it can be guided in the inside of the pressure vessel. After the vessel and the duro-plastic material have been cooled down to a specific temperature, a duro-plastic material is applied on the outside of the vessel Vital for the invention is that the temperature of the vessel while applying the external coat remains below the level, at which the internal coat has been applied. The pressure vessel should, therefore, have a temperature below 250 °C while applying the outer coat, advantageously 165 to 250 CC. The duro-plastic material can be applied on the outside of the vessel through spraying on a rotating vessel, by spraying from jets arranged in a circle, wherein the vessel vis-a-vis the jets or the jets vis-a-vis the vessel does a relative movement. The coated outer layer should have even thickness between 500 and 1500 (jm. After applying the plastic layer the vessel can cool down further, until the duro-plastic layer is cooled down. The cooling process can, however, be accelerated by air jet taking into consideration the hardening behavior of the plastic. It is advantageous to subject the vessel with the applied outer coat to a baking process for the outer coat. After ending the processes for coating the test, a final assembly, filling and a test of the finish vessel can conclude. The recommended process and pressure vessel for fire extinguishing medium manufactured according to this process have the advantages of a longer working life vis-a-vis conventional pressure vessels. This kind of coated fire extinguisher needs to be replaced less often, because these have a longer working life, which is primarily due to higher tensile strength of its internal and external coating. In the following the invention should be described with the help of a scheme and a figure. The numbers in the Figure 1 represent the following: 4 1. Bringing-in the vessel in the process or the flow path 2. Heating-up of the vessel in a heating oven 3. Bringing-in the duro-plastic coating powder in the inside of vessel 4. Heating phase by means of air jet and hardening of internal coat 5. Intermediate storage 6. Outer coat 7. Baking of outer coat 8. Final assembly, filling and testing of the finish vessel. As Figure 1 shows, the pressure vessel is brought in the process and a flow path, which can represent a transport belt. Thereafter, follows the heating-up of the vessel in a heating oven. The duro-plastic coating powder in brown color is brought by means of lance in the vessel inside, i. e. it is injected, so that the entire internal surface is covered uniformly and with even thickness. As far as the proposed thickness of, for example, 1 mm is reached, a cooling of the vessel follows in an air jet, the consequence of which is the hardening of internal coating. At a temperature of, for example, 200 °C a red outer coating is sprayed in a manner that duro-plastic coating material is applied by means of jets surrounding the vessel, until the outer layer has reached a thickness of 1.2 mm. Thereafter, follows a baking of outer layer in a baking oven, which is operated at temperatures of 300° C. The pressure vessel is then cooled in ambient air through a 12-hour storage. Thereafter, follows a check, the final assembly, the filling with fire extinguishing medium and the testing of finish vessel. Thereafter, the fire extinguisher can be delivered to the customer. The process steps 5 and 7, as the scheme shows, can also be by-passed. These represent alternatives for certain duro-plastic materials. 5 WE CLAIM : 1. Process for applying corrosion protection coat on a pressure vessel for fire extinguishing medium, wherein the vessel, preferably in a heating oven, is heated up to ap specified temperature, a duro-plastic material is uniformly applied on the internal wall of the pre-heated vessel, and after a partial cooling and, if necessary, after an intermediate storage a duro-plastic material is applied on its outside at low temperatures, after which the vessel is assembled, filled and tested. 2. Process as per claim 1, is characterized by the fact that die coating temperature for the internal coating is 250 to 300 °C. 3. Process as per claim 2 is characterized by the fact that the internal coat is applied to reach a thickness of 500 to 1000 um. 4. Process as per claims 1 to 3 is characterized by the fact that the vessel is rotated around its lengthwise axis while applying the internal coat. 5. Process as per claims 1 to 4 is characterized by the fact that the cooling speed of the vessel is egulated in conjunction with the hardening behavior of the coating material (powder). 6. Process as per claim 5 is characterized by the fact that the as per cooling speed is regulated by means of circulating air. 7. Process as per claims 1 to 6 is characterized by the fact that the coating temperature for the outer coat is 165 to 250 °C. 8. Process as per claims 1 to 7 is characterized by the fact that the outer coat is post-treated after a baking process. 9. Process as per one of the claims 1 to 8 is characterized by the fact that the internal coat is done by means of lance. 10. Process as per claim 9 is characterized by the fact that the throughput of the lance is controlled in conjunction with the form of internal wall. 6 11. Pressure vessel for a fire extinguishing medium, coated as per one of the claims 1 to 10 is characterized by a duro-plastic coat. 12. Pressure vessel as per claim 11 is characterized by the fact that the internal coat has the color blue and the external coat has the color red. Dated this 7th day of July, 2006. HIRAL CHANDRAKANT JOSHI AGENT FOR MINIMAX MOBILE SERVICES CMBH & CO., KG. 7 ABSTRACT The invention relates to a process for applying an anti-corrosive coat on a pressure vessel for fire extinguishing medium, wherein the vessel, preferably in a heating oven, is heated-up to a specified temperature, a duro-plastic material is applied uniformly on the internal wall of the pre=heated vessel, and after a partial cooling down and, if necessary, after an intermediate storage, a duro-plastic material is applied on its outside at low temperatures, whereupon the vessel is assembled, filled and tested. The invention based pressure vessel, preferably a fire extinguisher, has the advantage, that due to a higher tensile strength of the internal and external coat a longer working life is achieved. To, The Controller of Patents The Patent Office, Mumbai. 8 Appl. No. : Applicant : MINIMAX MOBILE SERVICES GMBH & CO.,KG.No. of Sheets : 01 / / Sheet No. : 01 --T i_n m VXD OJ 1 r r t en CO s / m % '2 HIRAL CHAMDRAKANT JOSHI AGENT FOR MINIMAX MOBILE SERVICES GMBH & CO.,KG

Documents:

1086-MUM-2006-ABSTRACT(29-7-2009).pdf

1086-mum-2006-abstract(complete)-(10-7-2006).pdf

1086-mum-2006-abstract(granted)-(7-9-2010).pdf

1086-mum-2006-abstract-1.jpg

1086-mum-2006-abstract.pdf

1086-mum-2006-cancelled pages(29-7-2009).pdf

1086-MUM-2006-CLAIMS(29-7-2009).pdf

1086-mum-2006-claims(complete)-(10-7-2006).pdf

1086-mum-2006-claims(granted)-(7-9-2010).pdf

1086-mum-2006-claims.pdf

1086-MUM-2006-CORRESPONDENCE(19-9-2008).pdf

1086-MUM-2006-CORRESPONDENCE(30-6-2011).pdf

1086-mum-2006-correspondence(9-10-2006).pdf

1086-mum-2006-correspondence(ipo)-(23-9-2010).pdf

1086-mum-2006-correspondence-received.pdf

1086-mum-2006-description(complete)-(10-7-2006).pdf

1086-MUM-2006-DESCRIPTION(COMPLETE)-(29-7-2009).pdf

1086-mum-2006-description(complete).pdf

1086-mum-2006-description(granted)-(7-9-2010).pdf

1086-MUM-2006-DRAWING(29-7-2009).pdf

1086-mum-2006-drawing(complete)-(10-7-2006).pdf

1086-mum-2006-drawing(granted)-(7-9-2010).pdf

1086-MUM-2006-FORM 1(29-7-2009).pdf

1086-mum-2006-form 18(10-7-2006).pdf

1086-mum-2006-form 2(29-7-2009).pdf

1086-mum-2006-form 2(complete)-(10-7-2006).pdf

1086-mum-2006-form 2(granted)-(7-9-2010).pdf

1086-MUM-2006-FORM 2(TITLE PAGE)-(29-7-2009).pdf

1086-mum-2006-form 2(title page)-(complete)-(10-7-2006).pdf

1086-mum-2006-form 2(title page)-(granted)-(7-9-2010).pdf

1086-MUM-2006-FORM 26(30-6-2011).pdf

1086-mum-2006-form-1.pdf

1086-mum-2006-form-2.doc

1086-mum-2006-form-2.pdf

1086-mum-2006-form-3.pdf

1086-mum-2006-form-5.pdf

1086-mum-2006-general power of attorney(19-10-2006).pdf

1086-MUM-2006-REPLY TO EXAMINATION REPORT(29-7-2009).pdf