“It’s Leaking Again” — Those Dreaded Words

Whether you’re in the water treatment, chlorine, or bottled gases industry, few words cause the same dismay as those three. The natural inclination is to blame the sealant, but in many cases, the sealant is not to blame.

Fluoramics has done a fishbone analysis on the causes of leaks, and we will break down the elements in this eight-part series.

  1. Low-Cost, Low-Quality Fittings
  2. Fitting Material Selection
  3. Cracked Plastic Fittings
  4. Tape or No Tape, Type of Tape
  5. Cold Flow
  6. Repairs & Maintenance
  7. Gas Attack & Chemicals
  8. Type of Thread Sealant

Today we will be focusing on part five: Cold Flow

Cold flow, also known as creep, is the gradual deformation of a material under sustained pressure or stress at normal operating temperatures. Plastic bends, moves, is happiest in its relaxed state… and will do its best to get there!

In threaded connections, cold flow leads to a loss of compression which causes gaps where leaks will form. The sealant itself hasn’t failed, but the material around it has moved, reducing the effectiveness of the seal.

How Cold Flow Contributes to Leaks

Many sealing materials and thread compounds are used in plumbing, gas, and industrial applications because they provide excellent chemical resistance and lubrication. However, in materials prone to cold flow, constant pressure can cause the sealant or the fitting material itself to shift, leading to potential leaks.

Here’s how this happens:

  • Material shifts over time
    • The fitting deforms under pressure, loosening the seal
  • Threaded connections lose compression
    • As the material creeps, fittings may loosen, creating small gaps where leaks develop
  • Pressure and temperature changes accelerate the process
    • Systems that undergo frequent pressure and/or temperature changes experience an even faster breakdown of the seal

Common Situations Where Cold Flow Causes Problems

  • Plastic or soft metal fittings – Materials like brass, aluminum, and certain polymers are more susceptible to deformation under stress, making them prone to cold flow issues.
  • High-pressure systems – Pressurized gases and fluids put continuous stress on fittings, which can lead to gradual material shifts and leaks.
  • Repeated disassembly and reassembly – Each time a fitting is taken apart and reinstalled, it may lose some of its ability to maintain a tight seal due to material fatigue and creep.

How to Prevent Cold Flow-Related Leaks

Don’t blame the sealant! Consider these solutions instead:

  • Choose the Right Sealant
    • A high-performance thread sealant like LOX-8 is designed to remain in place under pressure and temperature fluctuations. Unlike some softer materials, LOX-8 resists creep, reducing the likelihood of leaks.
  • Select More Rigid Materials When Possible
    • Harder metals or reinforced plastics can help reduce the risk of cold flow, especially in high-pressure applications.
  • Properly Torque Fittings
    • Over-tightening can speed up material deformation. Follow manufacturer torque recommendations to avoid excessive stress.
  • Inspect and Maintain Seals Regularly
    • In high-pressure or critical systems, routine inspections can help detect early signs of material creep before leaks develop.

Cold flow is a common but often overlooked cause of leaks in piping systems. Instead of assuming the sealant has failed, consider whether the fitting material or the sealing surface has deformed over time. By selecting the right materials and sealants, you can prevent leaks and keep your systems running smoothly.

Use Fluoramics Sealants

Assuming you’ve found the source of your leaks, Fluoramics’ sealants are an excellent option to ensure no further leaking.

  • LOX-8 Thread Sealant is highly recommended where oxygen or harsh chemicals such as chlorine or powerful oxidizers are present. It is the product of choice in applications where critical safety and resistance to aggressive chemicals are primary requirements. Providing superior performance as a sealant and anti-galling agent, LOX-8 withstands both high extreme temperatures and high pressure, plus it is NSF-approved for food processing facilities.
  • LOX-8 Full Density Thread Seal Tape is a multipurpose pipe sealing tape for sealing threads and preventing leaks. It is suitable for sealing threaded connections in multiple environments, is oxygen-approved, and is colored green to designate suitability for use on oxygen connections. It may be used alone or with Fluoramics’ pipe thread sealants.
  • Formula-8 seals threads in gas, liquid, and vacuum service. Oxygen-safe and NSF-approved for food processing facilities, Formula-8 is a water-based thread-sealing compound compatible with hydraulic oils and systems, PVC piping, cryogenics, and high temperatures. This sealant works by wetting into and sealing threaded joints when torqued and is engineered to seal over the entire thread length for the life of the joint in liquid, gas, and vacuum service.

If you haven’t found the source of your leaks, stay tuned for the next edition of Don’t Blame the Sealant where we will discuss Repairs & Maintenance.

Shop LOX-8 Thread Sealant Now> LOX-8 Thread Sealant

Shop LOX-8 Full Density Thread Seal Tape Now> LOX-8 Full Density Thread Seal Tape

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