Fire-stop stack fitting and method of using same

Claim 1

A fire-stop stack fitting for providing a fire-retardant fluid-conveying pipe coupling joint embedded in a concrete barrier, said stack fitting comprising: a cylindrically-shaped coupling wall having opposite first and second ends for forming a passage therethrough, said cylindrically-shaped coupling wall having opposite openings for receiving fluid conveying pipes therein to be coupled therewith, said cylindrically-shaped coupling wall further comprising a stop means positioned inside said passage for contacting the ends of first and second fluid conveying pipes inserted into the respective opposite first and second ends of said cylindrically-shaped coupling wall for preventing said pipes from passing further through said cylindrically-shaped coupling wall, said stop means having an internal surface which is exposed to fluids passing through said cylindrically-shaped coupling wall between said fluid conveying pipes inserted into opposite ends thereof; a cavity-forming wall whose second end is ridgedly affixed to said first end of said cylindrically-shaped wall and which is longitudinally spaced from said stop means, said cavity-forming wall defining an intumescent-material cavity extending about the circumference of said first fluid conveying pipe inserted into said opening at said first end which is open in an inwardly radial direction and in a first-end axial direction, said intumescent-material cavity being of a size for holding a sufficient amount of intumescent material for expanding radially inwardly, when heated, upon said first fluid conveying pipe and thereby closing off said first fluid conveying pipe; and, an attachment flange ridgedly affixed to said fire-stop stack fitting for attaching said fire-stop stack fitting to a concrete form, said flange extending radially outwardly at a first end of said cavity forming wall; whereby, said fire-stop stack fitting can be attached to a concrete form wall by fastening said attachment flange to said concrete form wall to thereby leave an intumescent-material cavity in a concrete wall which, when said concrete form wall is removed, is open from a first side of said concrete wall and which is adjacent to a pipe coupled to said first end of said cylindrically shaped coupling wall so that intumescent material located in said intumescent material cavity is quickly heated by a fire on said one side of said wall and is free to expand radially inwardly against said pipe.

Claim 8

A method of preparing a fire-stop plumbing stack comprising the following steps: selecting a flanged type fluid-conveying coupling joint to be attached by means of the flange to a concrete form wall, said flanged coupling joint having a cylindrically-shaped coupling wall with opposite openings for receiving first and second fluid-conveying pipes therein to be coupled therewith and a cavity-forming wall attached to said coupling wall at its first end for forming a cavity below said cylindrically-shaped coupling wall and above the flange but radially outside of a space in which said first pipe to be coupled to the joint is to be located, said cavity being open toward the flange end of the coupling and radially inwardly, said coupling having a stop means positioned inside said cylindrically-shaped coupling wall for contacting ends of first and second fluid-conveying pipes inserted into the respective openings of said first and second opposite ends of said cylindrically-shaped coupling wall; placing sufficient intumescent material in said cavity for closing said first pipe surrounded by said cavity and coupled to said coupling joint when said intumescent material is heated. attaching said flange to a concrete form wall and thereafter filling said form with concrete to embed said coupling joint, with said intumescent material in said cavity, in said concrete; and, attaching said first and second pipes to the ends of said coupling joint, with said first pipe being surrounded by said cavity and said intumescent material.

Claim 9

A method of preparing a fire-stop plumbing stack comprising the following steps: selecting a flanged type fluid-conveying coupling joint to be attached by means of the flange to a concrete form wall, said flanged coupling joint having a cylindrically-shaped coupling wall with opposite openings for receiving first and second fluid-conveying pipes therein to be coupled therewith and a cavity-forming wall attached to said coupling wall at its first end for forming a cavity below said cylindrically-shaped coupling wall and above the flange but radially outside of a space in which said first pipe to be coupled to the joint is to be located, said cavity being open toward the flange end of the coupling and radially inwardly, said coupling having a stop means positioned inside said cylindrically-shaped coupling wall for contacting ends of first and second fluid-conveying pipes inserted into the respective openings of said first and second opposite ends of said cylindrically-shaped coupling wall; placing sufficient intumescent material in said cavity for closing said first pipe surrounded by said cavity and coupled to said coupling joint when said intumescent material is heated. attaching said flange to a concrete form wall and thereafter filling said form with concrete to embed said coupling joint, with said intumescent material in said cavity, in said concrete; and, attaching said first and second pipes to the ends of said coupling joint, with said first pipe being surrounded by said cavity and said intumescent material.