Abstract:
A repair method for a plastic pipe network allows a damaged pipe to be disconnected from a fixture carrying it in the network without damage to or removal of the fixture carrying the pipe to be removed or the disruption of connections of other pipes connected to that fixture. The tool system used with my method provides a heating tool having an elongate heating head powered by an electrical powering source for insertion in the channel of the end portion of a thermoplastic pipe adhered in a thermoplastic fixture for removal without damage to the fixture. The tool system further provides a pipe removal tool having adjacently spaced prongs to be twisted about the periphery of a heated pipe portion for removal from the fixture at a temperature that causes no damage the fixture.

Description:
BACKGROUND OF INVENTION 
     1. Related Applications 
     There are no applications related hereto heretofore filed in this or any foreign country. 
     2. Field of Invention 
     My invention relates generally to repairing pipe in tubular conduit networks and more particularly to the heating of thermoplastic pipe adhesively carried in a polymeric fixture for removal of the pipe without damaging the fixture such as to prevent future reuse. 
     BACKGROUND AND DESCRIPTION OF PRIOR ART 
     Plastic pipe since its advent had been increasingly used in fluid conducting structures and networks until in the present day it has replaced metal pipe in numerous applications. Plastic pipe by reason of the nature of the material of its formation has been used with new and different fixtures than threaded metal pipe for interconnection in fluid conducting networks as it generally is not well or simply adapted to attachment by threaded type interconnections. By reason of this historicity and to fulfill practicality requirements, plastic pipe generally has been interconnected with and serviced by unthreaded plastic fixtures that are of the same or similar essential configuration as traditional threaded metallic fixtures historically used for the threaded interconnection of metal pipes. Plastic fixtures have generally evolved with pipe receiving ports having smooth cylindrical inner surfaces of slightly greater internal diameter than the external diameter of pipes to be received therein for joinder and the interconnected pipe generally is maintained in a fluid impervious seal in such fixture ports by a relatively thin layer of adhesive material between the adjacent surfaces of the pipe and fixture to be joined. This type of plastic fluid transmitting network has gained such popularity, reliability and acceptance that it now is approved for use in many structures regulated under building codes and is used extensively in non-regulated fluid network systems generally in the modern day, to an extent possibly greater than metal pipe. 
     Much if not most of the plastic pipe in present day use is formed of thermally active plastic material, quite commonly polyvinyl chloride (PVC) created by an extrusion process. The fixtures joining such pipe in a fluid transmitting network also are commonly formed of thermally active plastic material, though by a molding process rather than an extrusion process, and such fixture materials are commonly of a harder more dense nature with less if any softeners and with higher vicat points. Material commonly used for joining these pipes and fixtures is a quickly setting thermally active polymeric material that bonds to both adjacent surfaces being joined by reason of thermal or chemical activity or both that occurs in a relatively thin layer beneath the adjacent surfaces of the material forming the elements being joined. 
     It often is necessary in existing plastic pipe networks to make changes, modifications, corrections and repairs. This activity has presented problems which heretofore have been considered but not completely and satisfactorily resolved. In general when the end of a plastic pipe has had to be removed from an adhesively joined fixture, the fixture has been cut out of the existing network, removed, and replaced with a new fixture. This usually has required the lengthening of most or all pipes interconnected with the replacement fixture by using additional lengths of pipe and connecting sleeves which results in the use of more fixtures in the system with resultant higher costs, higher probability of future maintenance problems and the expenditure of more workman time in reconnecting the pipes and fixtures. The instant invention allows the end portion of the pipe that is to be removed to make a repair to be removed, while salvaging the fixture and the interconnections of other pipes connected to the fixture for continued use, so that only the replacement for the removed pipe need be reconnected in the pre-existing fixture fluid transmitting network after repair. 
     In general historically it appears that it has not been considered possible or practical to use thermal means to release an adhered joint once established between thermal plastic pipe and a thermoplastic fixture in a fluid conducting network. The inventor has found, however, with many thermally active plastics and commonly used adhesives that with adequate control of temperatures and the amount of thermal work done, thermoplastic pipes can be effectively removed from thermoplastic fixtures without damaging the fixtures to prevent future use. Particularly, flexible PVC pipe when used with common commercially available adhesives and polymeric fixtures, may be cut near a fixture interconnecting it and the end portion of the pipe in the fixture heated from the inside to a point near its vicat temperature, such that the pipe is still coherent and somewhat configurationally self sustaining, and the adhesive cementing it to the fixture, or at least the adjacent surface areas of the adhesive and pipe, have softened sufficiently to allow release of the adhesive bond. The pipe then may be engaged by a particular disclosed two-tined tool and twisted sufficiently about the pipe axis to release the adhesive bond at a temperature at or somewhat below the vicat point of common PVC pipe. With such adhesives the softening temperature need not be exceeded, though the heat applied should not be applied for any longer period of time than necessary. If heat is applied to a PVC pipe joined in a fixture port at temperatures near the vicat point of the pipe for lengthy period, the heated PVC pipe may become sufficiently softened as to allow excessive stretching or to lose its coherence, either of which may prevent or hinder extraction of the pipe from the interconnecting fixture port. 
     The vicat softening temperatures of polyvinyl type plastics used in smaller flexible extruded pipe of modern day commerce vary somewhat, depending on the specific composition of the plastic and the nature of its polymerization, but generally range between approximately 220° to 260° Fahrenheit. The temperature of the polyvinyl pipe in a fixture must be somewhat regulated as the slump temperature at which PVC pipes lose their configurational stability generally is not too far above their vicat temperatures. The vicat point of a particular pipe may be estimated empirically by practical experience, as aided by some thermal measuring device or by use of my extraction tool herein disclosed for the material of formation of the particular pipe. 
     The transmissability of heat by PVC is such as to give some range for the amount of heat work that may be input to allow removal of PVC pipe from a fixture. The appropriate temperature and its application time may be empirically determined fairly readily by use of the instant extraction tool. The tool will not extract PVC pipe until the interface of adhesive and adjacent pipe surfaces is sufficiently softened to release the adhesive bond. Use of the tool also determines if and when PVC pipe is sufficiently above its vicat point to lose its configurational stability or stretch sufficiently to lose its coherence to prevent pulling. 
     My invention does not reside in any one of these features individually, but rather in the synergistic combination of all of its structures and methods which give rise to its functions, as hereinafter claimed. 
     DESCRIPTION OF PRIOR ART 
     Mohr, U.S. Pat. No. 2,429,888, shows a thermal method of debonding parts in a fluidic distribution system that have been soldered together. In such debonding both the pipe and fixture involved become pliable, if at all, at very substantially higher temperatures than the liquefying temperature of the bonding solder. U.S. Pat. No. 3,246,393, discloses a method for removing a hose from a metallic fixture while salvaging the fixture which involves heating the fixture to a temperature high enough to soften the plastic hose carried therein to allow removal. Here the fixture is heated rather than the hose and the metal fixture would not be damaged at temperatures that would destroy the attached hose. Tupy, U.S. Pat. No. 3,906,612, shows a metallic cylinder having an internal baffle to allow heating by an external gas flame, provided by a separate tool, for internal placement in a thermoplastic pipe for removal from a fixture. The flame heating of the Tupy tool is substantially different from the electrically powered heating of the instant tool and would not provide the benefits of electrically powered heating. 
     SUMMARY OF INVENTION 
     My tool system for repair of plastic pipe networks comprises a heating tool, an electrical powering source and a pipe removal tool. The heating tool provides a body with a handle to aid manual manipulation and an elongate connecting rod extending forwardly from the body to releasably interconnect a heating head spacedly distant from the body. The connecting portions of either the heating tool or the heating head may have the upward end part bent to extend angularly, normally perpendicularly, to the portion joining the heating tool or heating head respectively so that the axis of the cylindrical heating head may be perpendicular to the axis of the connecting element of the heating tool which may make use of the tool easier with some pipe network configurations. Heating tool electrical circuitry having switching means communicates from a battery type electrical powering source through the body and heating head support to the outer end of the heating head support which releasably interconnects the heating head in electrical communication with the heating tool electrical circuitry communicating with the powering source. The heating head provides a cylindrical body having means for supportive and electrical interconnection with the forward portion of the heating tool connecting rod and carries an electrically powered resistive heating element for electrical interconnection with the heating tool electric circuitry. The heating head has an external diameter slightly less than the internal diameter of a pipe to be removed from a fixture but great enough to be in close proximity to the internal surface of a pipe to be removed when inserted therein to aid somewhat uniform heat transfer between the heating head and the pipe to be removed thereby. The electrical powering system provides the source of electric energy that communicates through the heating tool electrical circuitry to the resistive heating element of the heating head to generate heat in and about the heating head. The source of the electric energy preferably is a battery either associated with the tool body or releasably separate therefrom and electronically interconnected therewith. 
     The pipe removal tool is a T-shaped structure having an elongate handle structurally supporting a medial normally extending relatively thin pipe extraction element comprising a circularly cylindrical tube having diametrically opposed axially aligned slots extending at least through the axially outer end portion of its circumferential surface. The pipe extraction element has an external diameter slightly less than the internal diameter of a port from which a pipe is to be removed and a tapered outer end portion with rounded outer corners to aid insertion about a heated pipe and within the channel of a fixture port carrying it. 
     To use my tool system a pipe in an interconnected fluid conducting system that is desired to be removed from a fixture is severed spacedly outwardly of the port of the fixture carrying it. The heating tool with heating head and powering source attached is then manually manipulated to insert the heating head within the channel of the portion of the pipe to be removed that is carried within the port of the interconnecting fixture and the heating tool switch is activated to provide electrical power to the resistive element of the heating head to cause heating therein and thereabout. The heating tool is left in this heating position a predetermined period of time empirically determined from prior work with the same or similar materials or is removed periodically to test with the pipe removal tool. To test the pipe portion of the fixture for sufficient heating for removal, the extraction element of the removal tool is manually manipulated to extend one slit portion about the heated pipe and within the channel of the fixture carrying the pipe. If the pipe is not hot enough for removal the removal tool will not pass between the pipe and fixture port carrying it. If the pipe to be removed is deformable the removal tool is inserted within the fixture port with one slit portion of its extraction cylinder on the outside of the pipe to be removed and the other slit portion in the inside of the pipe and the tool twisted sufficiently about the extraction element axis to deform the heated pipe to be removed so that it grasped by the pipe extraction element and may be pulled from the fixture port carrying it is by the removal tool. At this point the fixture port that carried the removed pipe will not be heated sufficiently to be configurationally deformed and may be reused in the future to receive and interconnect the end portion of a repair pipe. 
     In creating such a tool system and process it is: 
     A principal object to provide a tool system to aid a process for removal of a short length of thermal plastic pipe from a thermal plastic fixture without damaging the fixture to prevent future reuse. 
     A further object is to provide such a tool system having a heating tool with interchangeable heating heads that may extend either elongately from the heating tool or perpendicularly therefrom for ease of use. 
     It is a further object is to provide a heating head for such a heating tool that is powered by a portable battery either releasably carried by the heating tool or separate therefrom and communicating therewith by wired interconnection. 
     A further object is to provide such a heating head that is insertable within the channel defined by a pipe portion to be removed from a fixture to provide heat in the channel of the portion of the pipe carried within the fixture port. 
     A still further object is to provide a pipe removal tool having an elongate handle structurally carrying a medially positioned perpendicularly extending circularly cylindrical removal element having a diameter slightly less than the diameter of a fixture port from which a pipe portion is to be removed and similar diametrically opposed slits to allow passage of one slit portion between the end portion of the pipe to be removed and the fixture port carrying it and the other slit portion within the channel of the pipe to be removed. 
     A still further object is to provide such a tool that may be inserted in and about a pipe length to be removed from a fixture to determine when the pipe to be removed has reached a temperature to allow deformation and release of adhesive bonding with the fixture port for subsequent removal by twisting of the tool relative to engage the pipe and allow pulling type removal from the fixture. 
     A still further object is to provide a method for using such a tool system that allows a thermal plastic pipe in a fluid conducting network to be severed spacedly adjacent the port of an interconnecting fixture for subsequent heating of the pipe length within the fixture that disrupts an adhesive bond between the pipe length and fixture to allow removal of the pipe length in an axial direction from the fixture without damaging the fixture to prevent such a reuse. 
     A still further object is to provide such a tool system and process that are of new and novel design, of rugged and durable nature, of simple and economic manufacture and use and that are otherwise well suited to the uses and purposes for which they are intended. 
     Other and further objects of my invention will appear from the following specification and accompanying drawings which form a part hereof. In carrying out the objects of my invention, however, it is to be understood that its features are susceptible to change in design and arrangement with only one preferred and practical embodiment being illustrated in the accompanying drawings and specified as is required. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In the accompanying drawings which form a part hereof and wherein like numbers of reference refer to similar parts throughout: 
         FIG. 1  is an isometric view of a heating tool of my system powered by a distal battery. 
         FIG. 2  is a partially cutaway isometric view of a heating tool of my system powered by a removable battery carried directly by the heating tool. 
         FIG. 3  is an enlarged vertical elongate cross-sectional view through the heating head of the heating tool of  FIG. 2 , taken on the line  3 — 3  thereon in the direction indicated by the arrows. 
         FIG. 4  is somewhat enlarged vertical cross-sectional view through the connecting structure that releasably interconnects the heating head with the heating tool, taken on the line  4 — 4  on  FIG. 2  in the direction indicated by the arrows thereon. 
         FIG. 5  is a vertical medial cross-sectional view through the body of the heating tool by  FIG. 1 , taken on the line  5 — 5  thereon in the direction indicated by the arrows. 
         FIG. 6  is a partially cut-away isometric view of a heating head that extends perpendicularly from the heating tool rather than elongately. 
         FIG. 7  is an isometric view of the pipe removal tool of the tool system. 
         FIG. 8  is a horizontal cross-sectional view through the pipe extraction element of the pipe removal tool of  FIG. 7 , taken on the line  8 — 8  thereon in the direction indicated by the arrows. 
         FIGS. 9A-9G  are semi-diagrammatic illustration of various steps involved in the instant method for removal of a length of pipe from the port of a fixture carrying it. 
         FIG. 10  is an electrical diagram in normal symbology showing use of an alternating current source of electric energy. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     My tool system provides generally heating tool  21  having heating head  22  interconnected with powering system  23  and pipe removal tool  24  to remove a length of pipe from a carrying fixture in pipe network  20 . 
     Pipe network  20  is comprised of a plurality of thermal plastic pipes  25  interconnected by a plurality of fixtures  26 , only a portion of which is illustrated in  FIGS. 9A-9E . Normally in thermal plastic pipe networks the interconnecting fixtures  26  are also formed of thermal plastic material. Generally the parts of such distribution network are supported in or on various structures that are immovable relative to each other so that if it is desired to modify, change or repair the network a pipe  25  must be cut to allow such activity and subsequently be re-established in the network. Commonly in the past when pipe modification in a network has been accomplished a pipe has been cut where a new component is to be installed or a repair made and to re-establish the network a new fixture is installed to interconnect both of the cut pipe ends into the network or, in the case of a required removal of a fixture, all pipes interconnected thereto will be cut and reconnected into the system with a new replacement fixture and at least one additional fixture for each cut pipe. The instant repair method allows a damaged pipe  25   a  to be cut at or near a fixture port and the portion of the pipe remaining in the fixture port subsequently removed without damage to that fixture port that would prevent re-use to allow establishment of the fluid system by use of only one additional fixture rather than two or more additional fixtures heretofore required. 
     My heating tool shown in  FIG. 1  provides elongate peripherally defined body  27  structurally interconnecting depending peripherally defined handle  28 . The forward juncture of body  27  and handle  28  defines trigger guard  29  defining trigger orifice  30  to internal rearward projection  32  of trigger guard  29  carries movably trigger  31  mounts on/off switch  33  changes states responsive to motion of trigger  31 . Trigger  31  is bias to a forward position by compression spring  34  which maintains switch  33  in a null off mode unless the bias of trigger  31  is removed by pulling the trigger rearwardly to bring switch  33  into its on mode. A latch or other known mechanism (not shown) may be provided if desired to maintain switch  33  in an on mode until reactivation of trigger  31  after establishment of the on mode. 
     The forward face  27   a  of body  27  defines rearwardly extending fastening arm cup  35  which defines channel  36  to receive the rearward end portion of heating head mounting arm  37 . The heating head mounting arm  37  is structurally carried in channel  36  of fastening arm cup structure  35  and extends forwardly a spaced distance therefrom to terminate in releasable connecting structure, as seen in FIG.  4 . The forward portion of heating head mounting arm  37  structurally defines tubular connector  38  extending forwardly therefrom and defining heating head connector arm  45  connecting channel  39 . Spacedly inwardly of its forward end tubular connector  38  defines radially inwardly extending fastening protuberances  40  to releasably maintain the heating head connector arm  45  therein. 
     Heating head  22  as shown in  FIGS. 2 and 3  provides forward cylindrical body  41  formed of some rigid material, preferably of an electrically insulative nature and having reasonably high heat conductivity to maintain and stabilize the temperature of the heating head somewhat uniformly throughout. The rearward portion of the body  41  defines axially aligned connecting arm chamber  42  communicating with somewhat radially smaller axially aligned heating wire channel  43  extending forwardly through the forward end of body  41 . The radially outer surface of body  41  supports a heating element  44 , in the instance illustrated comprising a spirally wound electrically resistive element. The overall diameter of the heating head  22  with heating element  44  in place thereon must be slightly less than the internal diameter of a pipe in which the heating tool  24  is to be used. 
     Heating head connecting arm  45  is an elongate tubular element defining internal channel  46  which is closed at its rearward end by plug  47  which defines a medial axially aligned channel  46   a  to allow passage of an electrically conductive powering wire therethrough. The heating head connecting arm  45 , forwardly adjacent its rearward end portion and radially outwardly of plug  47 , defines spaced annular fastening grooves  48  to receive fastening protuberances  40  defined in the inner surface of tubular connector  38  of heating head mounting arm  37  of body  27 . The external diameter of the rearward end portion of the heating head connecting arm  45  is such as to slidably fit within connecting channel  39  of tubular connector  38  and be there releasably maintained by interconnection of fastening protuberances  40  of the tubular connector  38  when positioned within annular fastening grooves  48 . To allow this interconnection the interconnected portions of the heating head connecting arm  45 , tubular connector  38  or both must be sufficiently resilient with appropriate retentent memory to allow their interconnection or if not, circumferentially spaced axially aligned channels (not shown) need be defined in the radial outer portion of heating head connecting arm  45  extending rearwardly from each annular fastener groove  48  to the rearward end of the connecting arm  45 . With such previously known type of interconnection the heating head connecting arm  45  may be rotated sightly relative to the heating head mounting arm  37  to releasably fasten fastening protuberances  40  in fastening grooves  48 . 
     Powering system  23  provides a direct current source  49  in the instance illustrated in  FIG. 1  comprising an ordinary automotive battery  49   a  and in the instance illustrated in  FIG. 2  comprising an ordinary hand tool battery  49   b . As seen particularly in  FIG. 5 , electric current passes from battery connectors  50  through wire connectors  51  to interconnect on/off switch  33  and heating element  44  in an electrical series type communication with each other so that the switch  33  controls power input from direct current source  49   a  to heating element  44 . As seen in  FIG. 2  battery  49   b  releasably interconnects by known standard connectors  50  partially carried in tool handle  28 . The powering system may also use an alternating current source  55  to energize the heating element  44  as illustrated in  FIG. 10 , if such a source is conveniently available in or about the area of pipe repair. 
     Pipe removal tool  24  as seen in  FIGS. 7 and 8  comprises rigid elongate cylindrical handle  52  structurally carrying in its medial portion perpendicularly extending pipe extraction element  53 . Handle  52  is circularly cylindrical element that may be solidly or peripherally formed and if peripherally formed preferably has enclosed ends to prevent debris entrance and maintenance in the channel. The pipe extraction element  24  is a circularly cylindrical tube having two diametrically opposed elongate slots  54  defined in its circumferential surface and extending from the outer end distal from handle  52  to a point spacedly adjacent to the handle  52 . The outer end corners defining slots  54  preferably are filleted and the outer edges of the pipe extraction element are tapered to a thin edge to allow easier entry of a split portion of the extraction element within a pipe to be removed and the other split element  53  to be inserted between a pipe to be removed and a portion of the fixture defining the port carrying the pipe to be removed. 
     Having described the structure of the tools of my system, the method of use of those system tools and resultant pipe removal process may be understood. 
     A portion of a fluid transmission system is shown in  FIG. 9A  where it is seen have one pipe portions  25  and damaged pipe portion  25   a  interconnected by T-type fixture  26 . To remove the damaged pipe section  25   a , that section is exposed from surrounding structures or earth to allow access and the damaged pipe portion  25   a  is severed spacedly outwardly of the port  26   a  of fixture  26  carrying the damaged pipe  25   a  at a position such that the length of the damaged pipe remaining in the fixture port  26   a  is somewhat less than the overall axial length of the body  41  of heating head  22 , as illustrated in FIG.  9 B. 
     As seen in  FIG. 9C  heating tool  21  then is assembled with a heating head  22 , of either straightened or angulated configuration as may be appropriate for most convenient use, as illustrated in FIG.  9 C. The heating tool  21  then is activated responsive to operation of trigger  31  and responsively current flows to heating element  44  to provide heat by direct transmission and radiation in body  41  and thereabout. The heating head  41  is preferably formed of some heat absorbing material that is electrically insulative, such as a ceramic or metallic ceramic, so that it might serve somewhat of a heat reservoir as seen in FIG.  9 C. 
     After the heating head  22  has attained an appropriate temperature, normally determined imperially from past experience with similar plastic pipes, fixtures and adhesives, the heating head  22  is moved within the channel defined by the portion of damaged pipe  25   a  remaining in fixture port  26   a  and there maintained for a predetermined period of time, again determined imperially from prior experience with similar materials. The heat generated in heating head  41  and heating element  44  is transferred to and through the remaining pipe portion  25   a  to heat that pipe portion, the outer surface thereof and adhesive material carried thereabout. When the temperature of the adhesive material fastening the remaining pipe portion  25   a  in port  55  has softened appropriately to allow removal, heating tool  21  is manually removed from the pipe portion  25   a , as illustrated in FIG.  9 E. 
     The pipe removal tool  24  then is manipulated by its handle  52  to position one arm  53   a  on the outside of heated pipe portion  25   a  and the other pipe extractor element  53   b  inside the channel of pipe element  25   a , as illustrated in FIG.  9 F. At this point the pipe portion  25   a  will be softened to allow deformability which will aid the insertion of the portions of pipe extraction element  53 , as indicated and shown in FIG.  9 F. 
     After such positioning of the pipe removal tool  24 , handle  28  is manually rotated somewhat to deform at least the upper end part of pipe portion  25   a  to deform that pipe portion somewhat to allow grasping by the pipe extraction tool  24  and the tool is moved outwardly and from away from port  26   a  of fixture  26  to extract the pipe portion  25   a  therefrom, as illustrated in FIG.  9 G. 
     The pipe removal tool  25  serves as a measuring device to determine if the temperature of damaged pipe portion  25   a  and the amount of heat work preformed thereon are sufficient to allow removal of that pipe portion from fixture  26 . If the tool  24  may not be inserted in the heated pipe portion  25   a  or may not be rotated to cause grasping engagement with the pipe portion  25   a , the pipe portion is not hot enough to be extracted and further heat will need to be applied by the heating head  22  in the same fashion as it was initially applied and the removal process thereafter repeated as indicated in the first instance. The heating of pipe portion  25   a  should not be hot enough to cause substantial slumping of that pipe portion from its initial cylindrical configuration and should not be great enough to disrupt the coherency of the pipe portion  25   a  as this would prevent subsequent removal of the pipe portion by use of the pipe removal tool  24 . 
     In this regard, it is to be remembered that the pipe portion  25   a  is being heated from within its medial channel and the material from which the pipe portion  25   a  is formed, even though it is thermally active, does not provide a transfer rapid of heat therethrough so the pipe portion will be hotter than the port  26   a  of the fixture  26  carrying it to provide some temperature range within which the instant removal process may be accomplished. It is further to be noted that many, if not most, of the adhesive materials used to sealably fasten thermal plastic pipe  25  in fixture  26  lose their adhesive characteristics at temperatures generally below the vicat points of either the plastic pipe or fixture and this further increases the temperature range within which my process is active. This active temperature range may be determined by a user from prior work with similar materials with very little experimentation by reason of the temperature range over which the process is operative. Preferably the amount of the electrical heating element  44  and therefore its electrical resistance is pre-determined to limit the amount of heat supplied to heating head  41  and thereabout so as to require a heating period of approximately at least two to five minutes to allow removal of pipe portion  25   a  from its carrying fixture to make it easier for the user to stay within the temperature window in which the instant removal process may be effectively and efficiently carried out. 
     After removal of pipe portion  25   a  from carrying fixture  26  fixture port  55  will be configurationally self sustaining and remain usable. The remaining damaged portion of pipe  25   a  may then be trimmed as necessary and a new portion of pipe fastened to the remaining portion of pipe  25   a  by a sleeve type connector (not shown) and interconnected in port  26   a  to repair the damaged fluid system to its original configuration by use of only one additional fixture. If such a repair were made prior to use of my process, the fixture  26  normally would have been cut out of the pipe network  20  and each of the three pipes  25  interconnected therewith would have been rejoined by use of a new fixture and additional lengths of pipe necessary to connect the original pipes  25  to the new fixture, which would have to joined to the original pipes  25  by new sleeve type connectors. This would require both a new “T” type fixture and three additional new sleeve type connectors, aside from the additional pipe that might be required. 
     If it is desired to insert a new fixture or subsystem into an existing pipe network, the process would be substantially the same as that described for repair of a damaged pipe. The particular pipe in which the fixture or subsystem is to be interconnected would be cut spacedly outwardly of the port of a fixture, and the new element or subsystem installed between the fixture and the cut pipe portion after removal of the cut pipe end portion adhered in the fixture port carrying it from that port. 
     The foregoing description of my invention is necessarily of a detailed nature so that a specific embodiment of its best known mode may be set forth as required, but it is to be understood that various modifications of detail, rearrangement, multiplication of parts and ordering of process steps might be resorted to without departing from its spirit, essence or scope. 
     Having thusly described my invention, what I desire to protect by Letters Patent, and