Compositions for preventing polythionic acid (pta) stress corrosion cracking on 300 series stainless steel and methods of using the same

Abstract

Compositions, systems and methods for treating stainless steel vessels to prevent polythionic acid stress corrosion cracking are described. Compositions include pre-mixed K 2 CO 3 solutions that can be diluted on-site to desired K 2 CO 3 concentrations via in-line mixing with water prior to placement within a stainless steel vessel to be treated.

1 . A system for treating a stainless steel vessel for prevention of stress corrosion cracking, the system comprising:
 a storage container configured to store a pre-mix K 2 CO 3  treatment solution and fluidically coupled with a first conduit;   a water source fluidically coupled with a second conduit;   a third conduit fluidically coupled with each of the first conduit, the second conduit and a stainless steel vessel to be treated; and   a waste vessel fluidically coupled with the stainless steel vessel,   wherein, when the system is in use, the pre-mix K 2 CO 3  treatment solution is transmitted from the storage container to the third conduit via the first conduit, water is transmitted from the water source to the third conduit via the second conduit, and the pre-mix K 2 CO 3  treatment solution and the water mix in the third conduit to form a diluted K 2 CO 3  treatment solution, the diluted K 2 CO 3  treatment solution receivable by the stainless steel vessel via the third conduit.   
     
     
         2 . The system of  claim 1 , wherein the first conduit further comprises an injection pump. 
     
     
         3 . The system of  claim 1 , wherein the first conduit further comprises an injection rate control valve. 
     
     
         4 . (canceled) 
     
     
         5 . The system of  claim 1 , wherein the second conduit further comprises a water injection rate control valve. 
     
     
         6 . The system of  claim 1 , wherein the second conduit further comprises a flow meter. 
     
     
         7 . (canceled) 
     
     
         8 . The system of  claim 1 , wherein the storage container is configured to store a pre-mix K 2 CO 3  treatment solution having a K 2 CO 3  concentration of between about 200 g and about 1120 g of K 2 CO 3  per liter of water. 
     
     
         9 - 17 . (canceled) 
     
     
         18 . The system of  claim 1 , wherein the system is configured to prepare a diluted K 2 CO 3  treatment solution that contains from about 0.1 to about 10 w/w % K 2 CO 3 . 
     
     
         19 - 22 . (canceled) 
     
     
         23 . A system for treating a stainless steel vessel for prevention of stress corrosion cracking, the system comprising:
 a storage container configured to store a pre-mix K 2 CO 3  treatment solution and fluidically coupled with a first conduit;   a water source fluidically coupled with a second conduit;   an educator coupled with each of the first conduit and the second conduit;   a third conduit fluidically coupled with each of the eductor a stainless steel vessel to be treated; and   a waste vessel fluidically coupled with the stainless steel vessel,   
       wherein,
 when the system is in use, the pre-mix K 2 CO 3  treatment solution is transmitted from the storage container to the eductor via the first conduit, water is transmitted from the water source to the eductor via the second conduit, and the pre-mix K 2 CO 3  treatment solution and the water mix in the eductor to form a diluted K 2 CO 3  treatment solution, the diluted K 2 CO 3  treatment solution receivable by the stainless steel vessel from the eductor via the third conduit. 
 
     
     
         24 . The system of  claim 23 , wherein the first conduit further comprises an injection rate control valve. 
     
     
         25 . The system of  claim 23 , wherein the second conduit further comprises a water injection rate control valve. 
     
     
         26 . The system of  claim 23 , wherein the second conduit further comprises a flow meter. 
     
     
         27 . (canceled) 
     
     
         28 . The system of  claim 23 , wherein the storage container is configured to store a pre-mix K 2 CO 3  treatment solution having a K 2 CO 3  concentration of between about 200 g and about 1120 g of K 2 CO 3  per liter of water. 
     
     
         29 - 37 . (canceled) 
     
     
         38 . The system of  claim 23 , wherein the system is configured to prepare a diluted K 2 CO 3  treatment solution that contains from about 0.1 to about 10 w/w % K 2 CO 3 . 
     
     
         39 - 42 . (canceled) 
     
     
         43 . A method of treating a stainless steel vessel for prevention of stress corrosion cracking, the method comprising:
 a) incorporating a stainless steel vessel into a system according to  claim 1 ;   b) injecting a diluted K 2 CO 3  treatment solution into the stainless steel vessel until the stainless steel vessel is filled or substantially filled with the diluted K 2 CO 3  treatment solution;   c) maintaining the diluted K 2 CO 3  treatment solution in the stainless steel vessel for a predetermined period of time;   d) removing the diluted K 2 CO 3  treatment solution from the stainless steel vessel.   
     
     
         44 . The method of  claim 43 , wherein the diluted K 2 CO 3  treatment solution is removed from the stainless steel vessel to a waste vessel. 
     
     
         45 . (canceled) 
     
     
         46 . The method of  claim 43 , wherein step c) is performed at a temperature of up to 50° C. and/or the predetermined period of time is at least two hours. 
     
     
         47 . The method of  claim 43 , wherein step b) is performed under an inert atmosphere. 
     
     
         48 . The method of  claim 43 , wherein step c) further comprises measuring the pH of contents within the stainless steel vessel, the contents comprising the diluted K 2 CO 3  treatment solution. 
     
     
         49 . A method of treating a stainless steel vessel for prevention of stress corrosion cracking, the method comprising:
 a) incorporating a stainless steel vessel into a system according to  claim 23 ;   b) injecting a diluted K 2 CO 3  treatment solution into the stainless steel vessel until the stainless steel vessel is filled or substantially filled with the diluted K 2 CO 3  treatment solution;   c) maintaining the diluted K 2 CO 3  treatment solution in the stainless steel vessel for a predetermined period of time;   d) removing the diluted K 2 CO 3  treatment solution from the stainless steel vessel.   
     
     
         50 . The method of  claim 49 , wherein the diluted K 2 CO 3  treatment solution is removed from the stainless steel vessel to a waste vessel. 
     
     
         51 . (canceled) 
     
     
         52 . The method of  claim 49 , wherein step c) is performed at a temperature of up to 50° C. and/or the predetermined period of time is at least two hours. 
     
     
         53 . The method of  claim 49 , wherein step b) is performed under an inert atmosphere. 
     
     
         54 . The method of  claim 49 , wherein step c) further comprises measuring the pH of contents within the stainless steel vessel, the contents comprising the diluted K 2 CO 3  treatment solution. 
     
     
         55 - 72 . (canceled)