Sprinkler Head Sealant

Laurie Gibbons
Fire Protection, Industry Applications
January 3, 2024

Permabond is pleased to announce Permabond LH057! Fire protection professionals assisted Permabond in designing the ideal sprinkler head sealant.

LH057 forms a complete seal but is low strength to allow sprinkler head replacement.

LH057 Sprinkler Head Sealant Key Features

  • Replaces pipe dope and tapes
  • Low strength
  • Seals cross-cut and mis-threaded fittings
  • Easy to apply – Easy to remove
  • Will not dry out or deteriorate over time
  • Suitable for use in dry-riser or wet-standpipe systems
  • Locks to prevent vibration loosening
  • Prevents corrosion
  • Solvent-free
  • Open container will not dry out
  • Eliminates ‘call back’ repair costs

Download the LH057 technical data sheet for more information. Note LH057 is for use on metals – do not use on plastic.

Fire protection professionals trust Permabond products for sealing connections in sprinkler systems. Products include:

General Purpose Pipesealant

Permabond® LH050 pipe sealant with PTFE is a general purpose pipe sealant that provides instant air pressure seal up to 1000 psi with limited hand tightening. After cure, the sealing capability is typically up to the burst rating of the pipe itself. The low locking strength allows easy disassembly of piping but is a bit strong for sprinkler head sealing.

Permabond® LH050 pipe sealant performs well on most metals, particularly steel and brass. It provides an excellent alternative to pipe dopes and pipe tapes for sealing pipe joints.

It cures anaerobically when in contact with metal parts (as in a threaded pipe joint). When applied, LH050 dispenses as a smooth paste, filling the entire space between the threaded parts. It then cures at ambient temperature to form a solid plastic, completely sealing against hydraulic fluids, air, gases and chemicals. In addition, it locks the pipes, plugs or fittings against vibration loosening, tampering and variable temperature effects.

Permabond LH050 is classified by Underwriters Laboratories Inc. ® for use in devices handling gasoline, petroleum oils, and natural gas (pressure not over 300 psig) not exceeding 2 in. pipe size; propane and butane not exceeding 1 in. pipe size. 66G9.

Permabond LH050 is classified by Underwriters Laboratories Inc. ® for use in sprinkler system and water spray system piping not exceeding 2 in. pipe size containing air, nitrogen, water, propylene glycol or glycerol antifreeze solutions. 66G9.

Metal Pipe Sealant for use in systems that also contain CPVC

Permabond LH056 is a pipe sealant designed for use in sealing metal pipes in sprinkler systems which may also contain CPVC piping. It forms an instant seal and once fully cured the seal will generally surpass the burst rating of the pipe.  Permabond Pipe Sealants use anaerobic technology to prevent leaks in sprinkler systems. Used in fabrication and installation, Permabond Pipe Sealants replace pipe dope and sealing tapes with a complete and reliable seal even if pipes are not completely seated. They prevent corrosion and lock against vibration loosening. They do not remain a paste, like pipe dope, but cure to a solid plastic seal. Cure is initiated by the presence of metal and the absence of air. It can also be too strong for sprinkler head sealing.

Permabond LH056 is FBC™ System Compatible. FBC™ System Compatible indicates that this
product has been tested, and is monitored on an ongoing basis, to assure its chemical compatibility
with FlowGuard Gold®, BlazeMaster® and Corzan® piping systems and products made with TempRite® Technology. The FBC System Compatible Logo, FBC™, FlowGuard Gold®, BlazeMaster®, Corzan®, and TempRite® are trademarks of Lubrizol Advanced Materials, Inc. or its affiliates.

Weld Sealing

Permabond HL126 is a very low viscosity anaerobic sealant used to seal weld porosities.

Directions for Use for Weld Sealing
1) Expose the weld. Remove dirt, rust, scale, and/or paint from the weld area to expose the metal surface.

2) Bleed the system of all water and pressure to allow the HL126 to wick into the porosities.
3) Heat the area to 50°C – 100°C (120°F-212°F). Using heat will expand and activate the metal as well as
evaporate any water. HEAT SHOULD NOT BE USED WITH A CHEMICAL SYSTEM. Consult the MSDS for information on the flash point, flammability and heat stability of the chemicals involved.
4) Apply HL126 to the warm welds with a brush, swab or clean rag. Wet the area thoroughly with the product so that it can wick into all the open areas within the metal and form a new seal.
5) If the porosity is large or there are several pin-holes in the same area, several applications may be necessary.

Sprinkler Head Sealing


LH057 Sprinkler Head SealantFor more information on Permabond LH057 Sprinkler Head Sealant, please contact Permabond.








For more information and product use instructions, download the flyer.

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