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.. m AOL the cut ends, and bond a sleeve plings. Cure these joints and sure that the nipple is on the coupling between the tapered ends. then measure the gap between tapering tool in exactly the same Make sure that the joints are locked the sleeve couplings. At this position as the first taper, (which up and fully cured before pressure point, determine the proper was used to measure the inser- testing the repair. length of the pipe nipple. This tion length). If the pipe is buried, excavate a working area large enough to allow for tapering tool rotation. Taper the cut ends of the pipeline and install the sleeve coupling using the proce- dure shown in Figure 1.8.5. 2. When damage is extensive (too large for replacement by a sleeve coupling), cutout the damaged sec- tion, taper the cut ends, and install two sleeve couplings and a pipe nipple as shown in Figure 1.8.6. This procedure requires sufficient slack in the line to make the final joint by lifting the pipe (or moving the pipe to one side) to engage the bell and spigot joint. Therefore, it may be necessary to remove addi- tional backfill from a buried line to allow for pipeline movement of sev- eral feet. a. Cut out the damaged section of Pipe. b. Taper one end of a piece of pipe at least as long as the damaged section. When tapering, care- fully observe the position of the nipple on the tapering tool. This taper wi I I be used as a gauge. Cut this nipple to the proper length in the following steps. c. When pipe is buried, excavate a working area large enough to allow for tapering tool rotation. Taper the cut ends of the pipe) ine and install the two sleeve cou- Figure 1.8.4 length is the sum of the distance between the two sleeve cou- plings, the insertion length of the tapered ends, and an additional "wet" make-up length to assure joint lock-up. Todeterminethe insertion length of the tapered ends, move one of the couplings to the side and use theend of the repair nipple made in the previous step to determine the dry fit into each bell. (Note: The dry fit must be very tight, i.e. use a 2 x 4 to drive the joint together tightly enough that it is difficult to separate.) The total length of the repair nipple is de- termined by adding these two measurements to the distance between the sleeve couplings and then adding the two make-up dimensions from Table 1.8.1. This added length is needed due to additional insertion which oc- curs because the adhesive acts as a lubricant. (Caution: This addi- tional insertion will be greater if a tight, dry fit is not achieved when measuring. It will also be different for each size of pipe.) After the final nipple length pp e e gth is determined, cut the other end of the nipple and taper it, making re 1.8.5 24 d. If solvent is used to clean bond- ing surfaces, allow the cleaner to evaporate. Then apply adhesive to all bonding surfaces, and in- sert the nipple into the line by lifting the line or moving it to one side. Pushing the pipe back into the line will push the nipple into the bell. Make certain that all tapers are tightly locked. Becare- ful not to cock the joint. 1.8.4 Leaking joints Any adhesive -bonded joints that leak during pressure testing MUST BE RE- MOVED AND REPLACED. Follow the procedures shown for Figure 1.8.6 us- ing two sleeve couplings and pipe nipple. Upon completion of any necessary repairs to the piping system follow the proper testing sequence to verify the system's integrity. TABLE 1.8.1 MAKE-UP DIMENSIONS (WET) Pipe Size Make-up Dimension::: (in.) (in.) {mmj 2 Q 1/8 3 3 75 3/16 5 4Qli 3/16 5 Example: for 2" (50mm) pipe: 2 x 1/8" = (2 x 3mm = 6mm) 1.8.6