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Pipe Size Diameter and Thread Sealant Use

Permabond LH050 general purpose anaerobic pipe sealant is for use on metal pipe.   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.  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.

So let’s break that down…

  • If you require UL Classification and the piping is used for handling gasoline, petroleum oils, and natural gas then 2 inches is the limit. 
  • If you require UL Classification and the piping is used for propane and butane then 1 inch is the limit.
  • If you require UL Classification and the piping contains air, nitrogen, water, propylene glycol or glycerol antifreeze solutions then 2 inches is the limit.

 

What if I don’t require UL Classification?

As an anaerobic pipe sealant, Permabond LH050 cures when confined between two metal surfaces.  The maximum gap between those surfaces should not exceed 0.020” (0.5mm) to achieve a fixture strength in 2 hours and full cure in 24 hours.  The gap between threads on pipe work less than 2 inches in diameter is usually less than that.

For 2-4 inch diameter pipe, Permabond recommends using ASC10 to support curing through the gap.  However, many of our customers prefer not to use the ASC10 and wait 72 hours to achieve cure.

We have limited information on using Permabond LH050 and greater than 4-inch pipe.

Directions for use according to pipe size.

For pipes up to 1 ½ inch diameter – Apply Permabond LH050 onto the leading 3-4 threads half way around the male pipe.

For larger pipes – Apply Permabond LH050 onto the leading 3-4 threads completely around the male pipe.  Large pipes will take longer to cure – to speed cure apply Permabond ASC10 to one or both surfaces, allow it to evaporate, then apply the Permabond LH050.  DO NOT mix ASC10 with the anaerobic adhesive sealants.

In both cases inspect to ensure a bead of pipe sealant is visible around the circumference of the pipe to ensure adequate sealant has been applied.

pipe sealant