Method and apparatus for plating threaded portion of high pressure gas cylinder

Abstract

A method and apparatus for plating a threaded portion of a high pressure gas cylinder is provided. The method includes: providing a high pressure gas cylinder having a gas containing portion and a threaded portion being formed on a top of the gas containing portion; locating an anode pipe, in which a plating solution passage is formed, inside the threaded portion; forming a closed chamber containing the threaded portion and the anode pipe; forming a flux of the plating solution inside the closed chamber; and forming a voltage difference between the anode pipe and the threaded portion, and plating the threaded portion.

1 . A method for plating a threaded portion of a high pressure gas cylinder, the method comprising:
 providing a high pressure gas cylinder having a gas containing portion and a threaded portion being formed on a top of the gas containing portion;   locating an anode pipe, in which a plating solution passage is formed, inside the threaded portion;   forming a closed chamber containing the threaded portion and the anode pipe;   forming a flux of the plating solution inside the closed chamber; and   forming a voltage difference between the anode pipe and the threaded portion, and plating the threaded portion.   
   
   
       2 . The method of  claim 1 , wherein, in the forming of the closed chamber, a bottom sealing portion isolates a bottom of the threaded portion from the gas containing portion, and a top sealing portion, which is formed in correspondence to the bottom sealing portion, isolates a top of the threaded portion from an outside to form the closed chamber. 
   
   
       3 . The method of  claim 1 , wherein, in the forming of the flux of the plating solution, the plating solution flows from the plating solution passage into the closed chamber so as to form the flux of the plating solution around the anode pipe. 
   
   
       4 . The method of  claim 1 , wherein, in the forming of the flux of the plating solution, the plating solution flows from the closed chamber into the plating solution passage so as to form the flux of the plating solution around the anode pipe. 
   
   
       5 . The method of  claim 2 , wherein the bottom sealing portion comprises a supporter and a rubber piece on a bottom of the anode pipe, the supporter has a diameter less than an inside diameter of the threaded portion, and the rubber piece is located on a top of the supporter and has a diameter greater than the inside diameter of the threaded portion. 
   
   
       6 . The method of  claim 2 , wherein the bottom sealing portion comprises a balloon portion, which is formed on the bottom of the anode pipe, and an inner pipe is formed inside the anode pipe so as to insert a fluid into the balloon portion. 
   
   
       7 . The method of  claim 1 , wherein, in the plating of the threaded portion, a plating layer is formed with thickness of approximately 1 to 100 μm. 
   
   
       8 . The method of  claim 1 , wherein, in the plating of the threaded portion, a nickel chloride solution is utilized to embody the plating layer, from the nickel chloride solution, the nickel chloride solution having a nickel chloride concentration of approximately 50 to 500 g/L, a boric acid concentration of approximately 5 to 50 g/L, a pH in the range of approximately 0.5 to 6.5, a use temperature of approximately 20 to 95° C., and a use voltage of approximately 3 to 20 V. 
   
   
       9 . The method of  claim 1 , wherein, in the plating of the threaded portion, a nickel sulfate solution is utilized to embody the plating layer, from the plating solution, the nickel sulfate solution having a nickel sulfate concentration of 100 to 500 g/L, a boric acid concentration of approximately 5 to 50 g/L, a nickel chloride concentration of approximately 2 to 80 g/L, a pH in the range of approximately 1 to 6.5, a use temperature of approximately 20 to 95° C., and a use voltage of approximately 3 to 20 V. 
   
   
       10 . The method of  claim 1 , wherein, in the plating of the threaded portion, a nickel sulfamate solution is utilized to embody the plating layer, from the plating solution, the nickel sulfamate solution having a nickel sulfamate concentration of 100 to 500 g/L, a boric acid concentration of approximately 5 to 50 g/L, a nickel chloride concentration of approximately 2 to 80 g/L, a pH in the range of approximately 1 to 6.5, a use temperature of approximately 20 to 95° C., and a use voltage of approximately 3 to 20V. 
   
   
       11 . The method of  claim 1 , wherein, in the plating of the threaded portion, a nickel fluoborate solution is utilized to embody the plating layer, from the plating solutions, the nickel fluoborate solution having a nickel fluoborate concentration of 40 to 500 μL, a boric acid concentration of approximately 5 to 50 g/L, a pH in the range of approximately 1 to 6.5, a use temperature of approximately 20 to 95° C., and a use voltage of approximately 3 to 20 V. 
   
   
       12 . The method of  claim 1 , wherein a diameter of the anode pipe is controlled so as to control the thickness of the plating layer, the plating layer being formed on ridges and pits of the threaded portion. 
   
   
       13 . The method of  claim 1 , wherein a surface of the anode pipe is partially masked so as to control the thickness of the plating layer according to each location of the threaded portion. 
   
   
       14 . The method of  claim 1 , wherein the providing of the high pressure gas cylinder provides the high pressure gas cylinder in which the plating layer is formed on an inside wall thereof. 
   
   
       15 . An apparatus for plating a threaded portion of a high pressure gas cylinder which has a gas containing portion and a threaded portion being formed on a top of the gas containing portion, the apparatus comprising:
 an anode pipe, on which a plating solution passage is formed;   a bottom sealing portion being formed on a bottom of the anode pipe, and isolating a bottom of the threaded portion from the gas containing portion;   a top sealing portion being formed in correspondence to the bottom sealing portion, and isolating a top of the threaded portion from an outside; and   a plating solution supplier supplying a plating solution to the anode pipe and the closed chamber.   
   
   
       16 . The apparatus of  claim 15 , wherein the plating solution passage is formed on a location which corresponds to the bottom of the threaded portion, and an inlet/outlet for the plating solution is formed on a side of the top sealing portion. 
   
   
       17 . The apparatus of  claim 16 , wherein the plating solution flows into the closed chamber through the plating solution passage, the flowed plating solution is discharged to the outside through the inlet/outlet for the plating solution so that a flux of the plating solution is formed around the anode pipe. 
   
   
       18 . The apparatus of  claim 16 , wherein the plating solution flows from the closed chamber into the plating solution passage, and the flowed plating solution is discharged to the outside through an opened hole of the anode pipe so that flux of the plating solution is formed around the anode pipe. 
   
   
       19 . The apparatus of  claim 15 , wherein the bottom sealing portion comprises a supporter and a rubber piece on a bottom of the anode pipe, the supporter has a diameter less than an inside diameter of the threaded portion, and the rubber piece is located on an upper portion of the supporter and has a diameter greater than the inside diameter of the threaded portion. 
   
   
       20 . The apparatus of  claim 15 , wherein the bottom sealing portion comprises a balloon portion being formed on the bottom of the anode pipe, and an inner pipe is formed inside the anode pipe so as to insert a fluid into the balloon portion. 
   
   
       21 . The apparatus of  claim 15 , wherein a diameter of the anode pipe is controlled to control the thickness of the plating layer which is formed on ridges and pits of the threaded portion. 
   
   
       22 . The apparatus of  claim 15 , wherein a surface of the anode pipe is partially masked so as to control the thickness of the plating layer at each location of the threaded portion.