X-Pando Pipe Joint Compound Expands as it Sets, Insuring a Tight Leak Proof Seal for Flanged or Threaded Joints, as well as Correcting Imperfections like Burred or Mutilated Threads in Pipe Threads, Flanges, and other Metal Surfaces. X-Pando Accomodates Fittings from Numerous Manufacturers with Different Size Threads and is Incredibly Economical- mix only what you need. This Realiable Pipe Joint Compound can Withstand Pressures as High as 5000 PSIG, Temperatures as High as 1000 F (538 C) and as Low as -300 F (-184 C), as well as Changes in Temperature and Vibration