STI Intumescent Firestop RTC Collar

Seal Plastic Pipes Penetrating Through Fire-Resistant Rated Walls and Floors

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What's special about these RTC collar?

  • Can be used with all common construction materials, including concrete floors, concrete over steel deck, concrete walls, concrete block walls and gypsum
  • One collar fits 3 and 4 inch pipes and couplings for an exact fit
  • Expansion starts at 320° F (160° C) and continues expanding up to 1000° F (538° C) to ensure a tight seal
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Intumescent RTC Firestop Collars are designed to seal around plastic pipes that penetrate through fire-resistance rated walls and floors. When temperatures exceed 320° F (160° C), the insert starts to expand and will seal out any fire or smoke.


STI-RTC350 Adjustable Firestop Collar, 3 or 4 inches, for pipes and couplings
  • Small profile to fit into small cracks
  • Not water soluble, so it can be used on water supply pipes and other pipes that might make condensation
  • Flexes without flake-off to prevent eye hazards
  • Expands quickly to help prevent the spread of fire and smoke
  • Swells up to 60 times its normal size to seal off every little crack and crevice
Product Name RTC Firestop Collar
Shell Construction Nom 22 GA Galvanized Steel 0.03" thick (0.76 mm)
Intumescent Insert Molded One Piece
Sizes Accommodated 3" trade size pipe (89 mm)
3" trade size pipe fitting (102 mm)
4" trade size pipe (114 mm)
4" trade size pipe fitting (127 mm)
Expansion Begins 320° F (160° C)
Volume Expansion 32x to 64x (free expansion)
In Service Temperature ≤ 120° F (49° C)






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