How to seal threaded pipe joints with Pipe Sealants

permabond pipe sealant adhesive

UL® performs various tests to determine the suitability of a pipe sealants for a particular use.  The classification does not state the strength of the product or the maximum sealing pressure for other uses.

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.

and

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.

For clarification, in the first statement, the 300 psig limitation is only for natural gas as tested by UL®.  UL® tested LH050 to 450 psig on natural gas to provide the classification of 300 psig.  UL® does not test the pipe sealant to failure but stops at 450 psig.

Similarly, Permabond LH150 is classified by Underwriters Laboratories Inc. ® for use in devices handling gasoline, petroleum oils, and natural gas (pressure not over 100 psig) propane and butane not exceeding 2 in. Again the 100 psig refers only to the natural gas and that value is granted based on testing with propane or butane.


What is the strength of Permabond Pipe Sealants?

In most cases we’ve determined that there is an instant seal of up to 1000 psi and after full cure, the pipe sealant will in general exceed the burst rating of the pipe.

How do anaerobic pipe sealants work?

Like all anaerobic adhesive sealants, it takes two things to cause cure – eliminate oxygen + provide metal ions.  So when confined from oxygen between the metal threads cure occurs.  They form a seal which is inert to water, steam, hydrocarbons, most acids, solvents, and glycol-based products.

In addition to products that are UL® Classified for specific needs, pipe sealants are available with WRAS, DVGW, and NSF/ANSI 61 certification for potable water.  There are also hydraulics grades which are unfilled resins that contain no particles which might clog or foul hydraulic screens and valves.

PERMABOND LH050 Anaerobic Thread sealant

Description

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.
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.

UL Classification

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.

Features & Benefits

  • Full cure seal to the burst rating of pipe
  • Easy to use and apply
  • Directional freedom
  • Does not contain solvents
  • Excellent chemical and temperature resistance
  • Cures at room temperature
  • Will not shred, tear or cause blockages

Physical Properties of Permabond LH050 Uncured Adhesive

Chemical composition Methacrylate esters
Appearance  

White

Viscosity @ 25°C 250,000 mPa.s (cP)
Specific Gravity 1.1
Particle size <10µm
UV fluorescence No

Typical Permabond LH050 Curing Properties

Maximum gap fill 0.5 mm  0.02 in
Time taken to reach handling

strength (M10 steel) @23°C

 

2 hours*

Full strength (M10 steel) @23°C 24 hours

*Copper and its alloys will make the adhesive cure more quickly, while oxidized or passivated surfaces (like stainless steel) will reduce cure speed. To reduce curing time, use Permabond activator A905 or ASC10. Alternatively, increasing the curing temperature will reduce curing time.

permabond pipe sealant adhesive


Typical Performance of Cured Permabond LH050 Adhesive

Torque strength (M10 steel ISO10964) Break 4 N·m     35 in.lb

Prevail 3 N·m    25 in.lb

Compressive shear strength (steel collar & pin ISO10123)  

7 MPa 1000 psi

Coefficient of thermal expansion 90 x 10-6 mm/mm/°K
Coefficient of thermal conductivity  

0.19 W/(m.K)


Permabond LH050 Chemical Resistance

1000 Hour immersion Temperature, °C (°F) Pressure, psi Results
50% Antifreeze / 50% water solution 126 (260) 60 No leak
Brake fluid 150 (300) 60 No leak
Differential lube 150 (300) 60 No leak
5W/30 Engine oil 150 (300) 60 No leak
Transmission fluid 150 (300) 60 No leak
Diesel fuel #2 25 (77) 60 No leak
ASTM fuel C 25 (77) 60 No leak
Water, steam 198 (390) 60 No leak
Air 150 (300) 60 No leak

This product is not recommended for use in contact with oxygen, oxygen rich systems and other strong oxidizing materials. This product may adversely affect some thermoplastics and users must check compatibility of the product with such substrates before using.

Surface Preparation

Though the anaerobic adhesives will tolerate a slight degree of surface contamination, best results are obtained on clean, dry and grease free surfaces. The use of a suitable solvent-based cleaner (such as acetone or isopropanol) is recommended. To reduce the curing time, especially on inactive surfaces (such as zinc, aluminum and stainless steel), the use of Permabond® A905 or ASC10 can be considered.


Directions for Use

  1. Prevent the tip from touching metal surfaces during application.
  2. Apply Permabond LH050 onto the leading 3-4 threads half way around the male pipe for pipes up to 1½ inches in diameter. For larger pipes, apply completely around the pipe.
  3. Screw fittings together. Permabond pipe sealants will seal even when the direction the pipe must face does not allow the complete seating of the threads.
  4. Visually inspect for a bead of pipe sealant around the entire pipe. If the sealant isn’t visible around the circumference, repeat the steps above using more sealant.

Permabond LH050 is designed for use on threaded metallic pipe joints; not recommended for use on plastic components.


Pipesealing instructions [Video]

How to seal threaded pipe joints with anaerobic thread sealant.

More than a distributor. We are your technical partner.

If you have any questions or want to find out more about the possibilities for your industrial application, please complete the contact form and one of our experts will be in touch.

If you have a problem with industrial adhesives, sealants, or electronic protection products and require advice, you can contact our technical support service. Our team can help you to optimize your processes and applications.

Liked this article?
If you found this article interesting please share it using the buttons below.

Share on linkedin
LinkedIn
Share on twitter
Twitter

Subscribe to our blog

Receive articles like this directly into your inbox.

MAKING REPAIRS IN DEMANDING CONDITIONS

This white paper examines how you can maximize staff time and minimize the number of hours when your critical items are out of action.