Patent Publication Number: US-2022221077-A1

Title: Fitting device and service valve including the same

Description:
FIELD OF INVENTION 
     The present invention relates to a fitting device that is easy to fasten and dismantle a pipe and a service valve including the same, and more particularly, to a fitting device for a copper pipe joint commonly used as an air conditioning component for air conditioning circulation, as well as a service valve including the same. 
     BACKGROUND OF INVENTION 
     Fitting accessories are generally used and fittings are diversely used throughout the world to serve as a joint to pipes (or hoses) (hereinafter referred to as “pipes”) from metal pipes or urethane hoses to water purifier hoses. 
       FIG. 1  illustrates a conventional fitting device. 
     As shown in  FIG. 1( a ) , when dismantling or separating a pipe  1  that was previously inserted (“pre-inserted pipe”), the conventional fitting device  2  expands an inner diameter of an inner bore lock washer spring by pressing both ends of the fitting device so as to remove the pipe that has been gripped (or fixed). However, in this process, both ends of the fitting device  2 , that is, a circular periphery should be continuously pressed until the pipe is released and, if force is applied to only one side of the periphery, an inner diameter of a ring lock washer spring cannot be evenly expanded in overall directions and causes an inconvenience in that the pipe  1  is not easy to remove. 
     In order to overcome such inconvenience, as shown in  FIG. 1( b ) , a C-shaped tool  3  is used as a washer such that the tool is fitted into the pre-inserted pipe  1 , followed by evenly applying force to both sides of the circular periphery at the end of the fitting device  2 , in order to separate the pipe  1 . However, the C-shaped tool  3  should be carried and managed along with different types or pipe diameters of the pipe  1  and, if the C-shaped tool  3  is lost or not carried, there is a problem of considerable inconvenience in removing the pipe  1 . Further, for most of the fitting devices  2 , when the pipe  1  is inserted into the fitting device, the pipe is often scratched by the ring lock washer spring and the repeatedly scratched pipe  1  is easily released even without applied force, hence causing a problem in that the pipe must be inserted after cutting out an end of the inserted portion of the pipe. 
     In general, an element for cooling is used for air conditioning in a cycle of compression-condensation-expansion-evaporation, wherein gas is introduced through a service valve and heat-exchange type air conditioning is performed by interaction between an indoor unit and an outdoor unit. 
     Herein, with regard to the service valve with reference to  FIG. 2( a ) , attachment of a pipe E to a conventional air-conditioning service valve A is implemented using the service valve A and threads of a thread nipple B included in the service valve rather than any fitting device. More particularly, after expanding the pipe E in a trumpet shape (C) by means of an expansion tool, the service valve A and the pipe E are fastened to each other using nuts corresponding to the thread nipple B while tightening and turning the nuts D. 
     As shown in  FIG. 2( b ) , when the air-conditioning service valve A shown in  FIG. 2( a )  is installed on the outdoor unit, an inconvenient operation of pipe expansion is required in order to modify the pipe E into a trumpet (C) shape at both of the indoor unit side and the outdoor unit side. Further, in order to fasten the pipe E with a nipple integrally with an evaporator at the indoor unit side, the trumpet-shaped (C) pipe E should be tightened with a monkey spanner using a nut D, which is a cumbersome operation. 
     Further, as shown in  FIG. 2( a ) , the service valve A at the outdoor unit side has a configuration such that a fluid (gas) is blocked by fitting a hexagonal wrench G into a hexagonal groove of a valve nut F and turning the same, so as to control flow thereof. As shown in the figures, the hexagonal wrench G is a “¬”-shaped wrench but a worker must carry different types and sizes of wrenches. 
     In other words, since the outdoor unit installed on an outer wall of a high-rise building has insufficient space between the unit and the outer wall, the valve nut F and the outer wall are too close to each other, and thus, a wrench in a straight form cannot be inserted into the hexagonal groove. Therefore, different types of “¬”-shaped wrenches must be carried. 
     Under such background, with regard to fastening the service valve A with the pipe E at the outdoor unit side, due to a narrow space depending upon conditions of the working environment, the nut D may not be tightened and turned even using a small monkey spanner. In such case, it is inevitable that the worker pokes the body out of a window (or door) when working on a banister, high floors, exterior walls, etc. In this case, if the worker accidentally drops a tool, the tool may hit a pedestrian&#39;s head or fall onto a passenger car bonnet. Worse still, there are cases where workers having tried to fasten the service valve A with the pipe E on the 20 th  floor of an apartment building fell to their death. As such, the above operation entails serious risk. 
     Accordingly, there is an urgent need for technical embodiments to solve the aforementioned problems. 
     The present inventors have invented a fitting device for easy insertion and removal of a pipe and a service valve including the same (Korean Patent Registration No. 1900927) and further proposed a fitting device for easy fastening and dismantling of a pipe in an alternative manner. 
     SUMMARY OF INVENTION 
     Technical Problem to be Solved 
     The present disclosure has been devised to overcome the aforementioned problems and reduce accident factors during work, and an object of the present invention is to provide a fitting device for easily, safely and conveniently fastening and dismantling a pipe, as well as a service valve including the same. 
     Technical Solution 
     With regard to a service valve that includes a service valve unit  100  having a valve handle  137  exposed to the outside and a fitting device  200  provided with a fitting housing  120  coupled to the service valve unit  100  at one end of the fitting housing, the present invention provides a service valve including a fitting device, characterized in that a fitting housing  120  may have an outer thread formed by a predetermined length on an outer ring at the other end of the fitting housing, and a first inner boss protruding from the other end at a predetermined depth, in addition, the fitting device  200  may include: a cap handle  50  screwed to the outer thread of the fitting housing  120 ; a ring lock washer spring  25  seated on the first inner boss; and a sleeve  35  fitted into an inner bore of the other end and interposed between the ring lock washer spring  25  and the cap handle  50 , wherein the sleeve  35  moves and presses the ring lock washer spring  25  by rotation of the cap handle  50  to expand a diameter of the inner bore (“inner diameter”), so as to dismantle a pipe  165  previously inserted (“pre-inserted pipe”) in the fitting device  200 . 
     According to one embodiment, the fitting housing  120  may include an inner thread formed by a predetermined length at the inner bore of the other end, wherein the first inner boss protrudes from the innermost side of the inner thread and the ring lock washer spring  25  is seated on the first inner boss, and the fitting device  200  may further include a guide ring nut  30  screwed to the inner thread to fix the ring lock washer spring  25 . 
     According to one embodiment, the fitting housing  120  may include a second inner boss protruding at a predetermined depth from the first inner boss toward the service valve, and the fitting device  200  may include: a support ring  20  which is seated on the second inner boss and comes into contact with an end of the pre-inserted pipe  165  to block further entry of the pipe  165 ; and a rubber packing  10  interposed between the support ring  20  and the ring lock washer spring  25 , an end of which is tapered to be in contact with tapered teeth protruding from an inner diameter of the ring lock washer spring  25 . 
     According to one embodiment, the support ring  20  may include at least one gas inlet perforated on an outer circumference thereof, and the rubber packing  10  may be formed in a tapered tubular shape having an outer diameter increasing toward the service valve, which is provided with a gas compression groove on a thickness surface at the service valve side, wherein a portion of gas introduced from the service valve presses the gas compression groove through the gas inlet, so as to improve air-tightness between the rubber packing  10  and the ring lock washer spring or increase fastening force between the ring lock washer spring  25  and the pipe  165 . 
     In addition, the present invention provides a fitting device  200  capable of dismantling a pipe  165  previously inserted into the fitting device  200 , including: a fitting housing  120  which includes an outer thread formed by a predetermined length on an outer ring at the other end thereof and a first inner boss protruding at a predetermined depth from the other end; a cap handle  50  screwed to the outer thread of the fitting housing  120 ; a ring lock washer spring  25  seated on the first inner boss; and a sleeve  35  which is fitted into an inner bore at the other end of the fitting housing  120  and interposed between the ring lock washer spring  25  and the cap handle  50 , wherein the sleeve  35  moves and presses the ring lock washer spring  25  by rotation of the cap handle  50  so as to expand a diameter of the inner bore, that is, an inner diameter. 
     Effect of Invention 
     The fitting device and the service valve including the same according to the present invention may exhibit effects of fastening or dismantling a pipe only by rotating the cap handle without scratching an outer surface of the pipe, even though a periphery of both ends of the fitting device is not continuously pressed as in the prior art and even if no further tool is carried and used. 
     In addition, the present invention can control a fluid (gas) by simply turning the valve handle even in a narrow space without loosening the nut. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates a conventional fitting device. 
         FIG. 2  is an exemplary view illustrating a conventional service valve and installation thereof. 
         FIG. 3  illustrates overall appearance of a service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 4  is a front view of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 5  is a plan view of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 6  is an exploded perspective view of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 7  is a cross-sectional view of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 8 a    is a cross-sectional view of a fitting device according to an embodiment of the present invention. 
         FIG. 8 b    illustrates a support ring according to an embodiment of the present invention. 
         FIG. 8 c    is a gas flow diagram of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 9  is a perspective cross-sectional view of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 10  is an exemplary view illustrating installation of the service valve including a fitting device according to an embodiment of the present invention. 
         FIG. 11  illustrates a front view, a right-side view, a left-side view and a plan view of the service valve including a fitting device according to an embodiment of the present invention, respectively. 
         FIG. 12  illustrates a state in which a pipe is fastened to the service valve including a fitting device and a fastening process according to an embodiment of the present invention. 
         FIG. 13 a    illustrates a support ring according to another embodiment of the present invention. 
         FIG. 13 b    and  FIG. 13 c    illustrate a state in which the support ring in  FIG. 13 a    is mounted on the fitting device. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF INVENTION 
     Hereinafter, exemplary embodiments disclosed herein will be described in detail with reference to the accompanying drawings, but the same or similar elements are assigned the same reference numbers regardless of the reference numerals, and repeated descriptions thereof will be omitted. The suffixes “unit” and “part” or “member” for components used in the following description are given or interchangeably used only considering ease of writing the specification, and do not have meanings or roles distinguished from one another in themselves. In addition, with regard to the embodiments disclosed in the present specification, if descriptions of related known technologies are considered to obscure the gist of the embodiments disclosed herein, detailed descriptions thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed in the specification is not limited by the accompanying drawings, and it should be appreciated that all modifications, equivalents and/or substitutions of the present invention are included in the spirit and technical scope of the present invention. 
     Terms including ordinal numbers such as first and second may be used to describe different components, but the components are not limited by the terms. 
     The aforementioned terms are used only for the purpose of distinguishing one component from other components. 
     When a component is said to be “connected” or “coupled” to another component, it is understood that a component may be directly connected to or coupled to another component but a different component may also exist therebetween. On the other hand, when a component is said to be “directly connected” or “directly coupled” to another component, it should be understood that no other component exists therebetween. 
     Singular expressions may include plural expressions unless the context clearly indicates otherwise. 
     In this specification, although terms such as “comprises” or “have” are intended to indicate that there are features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, it should be appreciated that possibilities of existence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof are not excluded in advance. 
       FIG. 3  illustrates overall appearance of a service valve including a fitting device according to an embodiment of the present invention. As shown in  FIG. 3 , a fitting device  200  is fastened to one end of the service valve unit  100 , wherein a pipe may be installed on the fitting device  200 , more particularly, may be inserted into a pipe inlet of a fitting housing  120 , and one end of the fitting housing  120  may be fastened to the service valve unit  100  having a valve handle  137  exposed to the outside. 
     For reference, a base  125  integrally formed with a valve housing  100   a  illustrated in  FIG. 3  may be attached to the outside of an outdoor unit, and a copper pipe  160  may be connected to a coupler of a compressor. 
     The fitting device according to one embodiment of the present invention may of course be widely employed in general hydraulic/pneumatic applications or injection fitting applications other than a refrigerating machine. 
       FIG. 6  is an exploded perspective view of the service valve including a fitting device according to an embodiment of the present invention. 
     As shown in  FIG. 6 , the valve housing  100   a  may be fastened with a valve nut  130  on one side thereof. That is, a thread formed on an inner bore of a coupler formed in one direction of the valve housing  100   a  is mutually engaged and fastened with another thread formed on an outer ring at one end of the valve nut  130 , so that the valve nut  130  is fitted into the valve housing  100   a  to be installed. 
     A circular groove may be formed along an outer circumference in the middle of the valve nut  130 , and a valve packing  130   a  may be fitted into the circular groove. A ring-shaped guide washer pin  130   b  which is partially opened may be fitted into a C-shaped groove at an end of the inner bore of the coupler formed in one direction of the valve housing  100   a.    
     In addition, a nut stopper  135  may be fastened while turning around the outer thread at the end of the valve housing  100   a  such that the valve nut  130  protruding outwardly penetrates a hollow part. Further, a valve stopper packing  177  may be interposed between the nut stopper  135  and the valve nut  130 . 
     The end portion protruding outwardly through the hollow part of the nut stopper  135  has a square shape and is provided with a thread groove on an outer surface thereof, and a handle screw  138  is fastened in the thread groove in a state in which a valve handle  137  having a square groove is fitted, so that the valve nut  130  may rotate in correspondence with rotation of the valve handle  137 . 
     After a pin nut  150  is fitted into a fluid (GAS) inlet  150   a  of the valve housing  100   a , a fluid stopper nut  155  may be fastened by turning the outer thread of the fluid (GAS) inlet  150   a . When the fluid (GAS) is introduced, the pin nut  150  may be pressed by an injection nut to introduce the fluid. 
     Meanwhile, the fitting housing  120  may be fastened to a coupler provided in one direction of the valve housing  100   a , as shown in  FIG. 3 . According to a specific embodiment, the coupler in one direction of the valve housing  100   a  may consist of a nipple  15  and, in order to be coupled to the nipple  15 , one end of the fitting housing  120  may have an inner bore formed with a thread by a predetermined length corresponding to the nipple  15  (see  FIG. 7  and the like). 
     On an outer ring at the other end of the fitting housing  120 , an outer thread may be formed by a predetermined length, to which a cap handle  50  having a thread corresponding to the inner side may be screw-fastened. Herein, the cap handle  50  may include a thru-hole formed as an entrance in the center portion, through which a pipe  165  is inserted to penetrate the center portion. An outer ring of the cap handle may be formed in a sawtooth shape to be easily turned by a hand. 
     An inner bore of the cap handle  50  may be engaged and fastened with the outer thread of the fitting housing  120 , wherein an end of the cap handle  50  is preferably folded by means of press processing to be caught on the outer thread of the protruding fitting housing  120 , thus preventing the cap handle  50  from being released from the fitting housing  120 . 
     Among the terms used in this specification, one end of the fitting housing  120  refers to an end of the fitting housing  120 , to which the valve housing  100   a  is coupled. On the other hand, the other end of the fitting housing  120  refers to an opposite end thereof, to which the cap handle  50  is coupled. 
     The fitting housing  120  may be formed in a straight tubular shape, however, the present invention is not limited thereto. Instead, as shown in  FIG. 10 , a variety of shapes such as an L-shape, a Y-shape, etc. may also be applied. 
     A sleeve  35  may be fitted into the other end of the fitting housing  120 , and the sleeve  35  may move forward or backward according to rotation of the cap handle  50 . 
     As shown in  FIG. 6  and the like, the sleeve  35  may include: a tubular sleeve body with an outer diameter corresponding to an inner diameter of the ring lock washer spring  25 ; and a wing part with an outer diameter corresponding to the outer diameter of the other end of the fitting housing  120 . Herein, one end of the sleeve body may have a sharp-tapered shape  37  while the wing part may be extended to be bent outwardly from the other end of the sleeve body. 
     As shown in  FIG. 8 a    and the like, the sleeve  35  may be installed such that the sleeve body is inserted into the other end of the fitting housing  120  and the wing part spans the other end of the fitting housing  120 . 
     Accordingly, when the cap handle  50  rotates in an unlocking direction and moves toward the fitting housing  120 , the wing part of the sleeve  35  is pressed toward the fitting housing side  120  and the sleeve body  37  of the sleeve  35  may expand teeth formed along a circumference of the inner bore of the ring lock washer spring  25  (see  FIG. 9( a ) ). 
     On the contrary, when the cap handle  50  rotates in a locking direction and moves away from the fitting housing  120 , the wing part of the sleeve  35  is not pressed toward the fitting housing side  120  but retracts the sleeve  35  by elastic force of the ring lock washer spring  25  and, at the same time, the inner bore of the ring lock washer spring  25  may be closed to reduce the inner diameter (see  FIG. 9 ( b ) ). 
     To this end, a length of the sleeve body may be defined such that, when the sleeve  35  is pressed toward the fitting housing  120 , a front end of the sleeve  35  reaches the tapered tooth portion of the ring lock washer spring  25 . 
     In this case, in order to move the sleeve  35  forward or backward whenever the cap handle  50  moves forward or backward, the cap handle  50  may be formed integrally with the sleeve  35  or may be attached to the sleeve  35 . 
     The ring lock washer spring  25  positioned in front of the sleeve  35  may include a first inner boss protruding at a predetermined depth from the other end of the fitting housing  120  so as to expand the inner bore without being pushed by a pressure of the sleeve  35 . 
     On the first inner boss, the ring lock washer spring  25 , specifically, a periphery of the ring lock washer spring  25 , is seated, wherein teeth formed on the inner bore of the ring lock washer spring  25  may be arranged to be tapered in a direction parallel to a pressing direction of the sleeve  35  by the cap handle  50 . 
     On the other hand, according to an embodiment of the present invention, the fitting housing  120  may include an inner thread formed by a predetermined length on the inner bore at the other end, and the first inner boss may protrude from the innermost side of the inner thread and the ring lock washer spring  25  is preferably seated on the first inner boss. 
     At this time, a guide ring nut  30  is preferably screwed to the inner thread so as to press/fix the periphery of the ring lock washer spring  25  seated on the first inner boss. 
     Accordingly, the ring lock washer spring  25  seated on the first inner boss is interposed between the first inner boss and the guide nut  30 , so that the guide nut  30  tightened along the inner thread may rigidly fix the ring lock washer spring  25 . As a result, even when the sleeve  35  is inserted into or released from the inner bore of the ring lock washer spring  25 , the ring lock washer spring  25  may not move but maintain the original position thereof. 
     Of course, the sleeve  35  penetrates a hollow part or an inner bore of the guide ring nut  30 , and the sleeve  35  may not move forward or backward without interference with the guide ring nut  30 . 
     Meanwhile, the fitting housing  120  may further include a second inner boss protruding at a predetermined depth from the first inner boss in the direction of the service valve unit  100 . 
     The support ring  20  is seated on the second inner boss wherein the support ring  20  is in contact with an end of the inserted pipe  165  to prevent the pipe  165  from further entering the service valve side  100 . 
     Although not specifically defined, the support ring may include a stepped part  163  to seat the support ring on the second inner boss, and a tubular diameter of the support ring  20  may be different before and after the stepped part  163 . 
     In addition, the support ring  20  may include at least one gas inlet perforated on an outer circumference of the support ring, wherein a space is present in the gas inlet in order to guide gas passing through the gas inlet to a gas compression groove of the rubber packing  10  to be described later. 
     The gas inlet may be perforated and formed on the outer circumference of the support ring  20 . However, according to another embodiment, as shown in  FIG. 13 a   , the gas inlet may comprise at least one groove formed in a length direction around the outer circumference of the support ring  20 . As shown in  FIG. 13 c   , the gas inlet through which the fluid enters may be formed around an outer periphery of the support ring  20 , thus easily manufacturing the support ring  20  while reducing production cost. 
     In this case, the fluid flowing through the gas inlet formed in a length direction of the outer circumference of the support ring  20 , as shown in  FIG. 13 b   , may directly/indirectly press the rubber packing  10  and the ring lock washer spring  25  in order, and therefore, fastening force between the ring lock washer spring  25  and the pipe  25  may be increased. 
     The rubber packing  10  may be interposed between the support ring  20  and the ring lock washer spring  25 . 
     At this time, a portion where the rubber packing  10  is installed, that is, a region from the second inner boss to the first inner boss of the fitting housing  120  may have a tapered shape to be gradually narrowed. Accordingly, the rubber packing  10  made of an elastic material may also have an outer ring in a tapered tubular shape that becomes narrower toward the first inner boss. 
     Further, a gas compression groove is preferably formed on a thickness surface of one end of the rubber packing  10 , that is, on the end facing the second inner boss. 
     Accordingly, some of the gas introduced through the gas inlet of the support ring  20  may press the rubber packing  10  toward the ring lock washer spring  25  with reference to the gas compression groove as an operating point. By pressing the rubber packing  10 , the rubber packing  10  may be compressed with the ring lock washer spring  25  so as to improve air-tightness between the rubber packing  10  and the ring lock washer spring  25 . 
     For this purpose, more preferably, a thickness surface of the other end of the rubber packing  10 , that is, the end facing the ring lock washer spring  25 , is tapered to be in contact with teeth protruding to be tapered in the ring lock washer spring  25 , so as to have a concave shape. 
     Hereinafter, a process of operating the fitting device according to an embodiment of the present invention will be described. 
     As shown in  FIG. 9( a ) , for example, when the cap handle  50  is turned to the right, that is, in the unlocking state, the end  37  of the sleeve  30  expands the teeth in the inner bore of the ring lock washer spring  25  by the cap handle  50 , as in the unlocking state shown in  FIG. 8( a ) , and therefore, the pipe  165  may be inserted without scratching an outer circumference of the pipe. Herein, the stepped part  163  formed on the inner bore of the support ring  20  inhibits further entry of the pipe  165 , whereby the end of the pipe  165  inserted into the fitting device  200  may contact the stepped part  163 . 
     As shown in  FIG. 9( b ) , for example, when the cap handle  50  is turned to the left, that is, in the locking state, the sleeve  30  retracts to reduce a diameter of the expanded inner bore of the ring lock washer spring  25  by the cap handle  50 , as in the locking state shown in  FIG. 8( a ) , and therefore, the teeth are closed to bite the pipe  165  and the pipe  165  may be firmly fixed. 
     In this regard, a rotational direction for moving the cap handle  50  forward and backward may be determined along a direction of threads formed between the cap handle  50  and the fitting housing  120 , and the present invention does not particularly limit the direction of the threads between the cap handle  50  and the fitting housing  120 . 
     At this time, when the gas fluid flows, as shown in  FIG. 8( c ) , the gas fluid may pass through the gas inlet formed on the outer circumference of the support ring  20  (for example, formed in each of four directions) and press the gas compression groove of the rubber packing  10 , whereby the rubber packing  10  may be compressed with the ring lock washer spring  25 . Herein, due to the tapered inner bore of the fitting housing  120  in which the rubber packing  10  is inserted, the periphery of the ring lock washer spring  25  may be further air-tightened. The higher the gas pressure, the more air-tightening effects can be expected. Since the rubber packing  10  compresses the tapered portion of the ring lock washer spring  25 , air-tightening effects may be maximized. 
     In addition, since the tapered teeth portion of the ring lock washer spring  25  is pressed to the rubber packing  10  by gas while biting the pipe  165 , fastening force between the ring lock washer spring  25  and the pipe  165  may be further enhanced. 
     On the other hand, whether the cap handle  50  is in the unlocking or locking state cannot be visibly checked. Therefore, when a worker turns the cap handle  50  to the right for locking as a habit, there is a serious problem in that the pipe  165  may burst due to gas pressure if the gas maintains a predetermined pressure. 
     Accordingly, in order to identify the locking or unlocking state of the cap handle  50 , as shown in  FIG. 5 , the fitting housing  120  may have a display unit A on the outer ring. The display unit A is in the form of a colored band, and the color is preferably visible in the locking state while being hidden in the unlocking state by the cap handle  50  to cover the outer ring of the fitting housing  120 , whereby the worker can identify the locking state and the unlocking state. 
     For example, if the display unit A is blue, it may be identified that the cap handle is in the locking state when a blue line is visible while being in the unlocking state when the blue line is invisible. As shown in  FIG. 4 , the pipe may be inserted in the unlocking state and then switched to the locking state, whereby the pipe  165  can be coupled to the fitting device  200  without damage to an outer surface of the pipe  165 . Therefore, a problem of scratching the outer circumference of a pipe when the pipe is inserted into the conventional fitting device may be overcome. 
     That is, as shown in  FIG. 8 a    and the like, according to an embodiment of the present invention, the teeth of the ring lock washer spring  25  are expanded in the unlocking state and do not interfere with the inserted pipe, thereby causing no problem as in the prior art. 
     Further, after coupling the pipe  165  to the fitting device  200 , the rubber packing  10  is compressed to the ring lock washer spring  25  by gas pressure. Therefore, the tapered teeth of the ring lock washer sprig  25  are pressed to the pipe  165  to improve fastening force between the ring lock washer spring  25  and the pipe  165 . 
     Meanwhile, with regard to removal of the pipe  165 , when dismantling the pipe  165  from the fitting device  200 , the valve handle  137  is gradually locked by starting from a high pressure valve. After the gas is fully exhausted, the valve handle  137  is completely locked at a low pressure valve. Then the cap handle  50  is turned to the right to switch the locking state to the unlocking state, thereby separating the pipe  165  without interference with the ring lock washer spring  25 . 
     As such, the preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings. The description of the present invention is for illustrative purpose only, and those skilled in the art to which the present invention pertains will understand that the present invention may be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. 
     Accordingly, the scope of the present invention is defined by the appended claims, which will be described later, rather than by the detailed description, and it should be interpreted that all modifications or variations derived from the meanings, scope, and equivalent concepts described in the claims are within the scope of the present invention.