Merflex® PEX OT® Oxygen Barrier Tubing

Our oxygen barrier tubing is designed to meet the rigorous demands of hydronic heating and radiant floor applications. Manufactured by Mercury Plastics, this high-performance tubing combines the proven benefits of cross-linked polyethylene (PEX) with a durable oxygen diffusion barrier to ensure long-term system integrity and corrosion prevention.

Engineered for Superior Performance

Merflex PEX OT Oxygen Barrier Tubing combines the proven durability of cross-linked polyethylene with a co-extruded EVOH oxygen barrier that protects closed-loop hydronic systems from corrosion. Designed for radiant and hydronic heating applications, it offers consistent performance, easy handling, and long-term reliability.

Durable & Reliable

  • Meets ASTM F876 and F877 standards
  • Complies with ASTM F2023 for chlorine resistance
  • Oxygen barrier layer meets DIN 4726
  • Rated for continuous service at 180°F at 100 psi

High-Quality Construction

  • Cross-linked polyethylene for lasting strength
  • Smooth inner surface minimizes pressure loss
  • EVOH oxygen barrier permanently bonded through co-extrusion
  • Excellent resistance to kinking and cracking

Easy to Handle & Install

  • Flexible for tight routing and simple coil handling
  • Maintains shape and stability under high temperatures
  • Compatible with standard hydronic fittings

Safe & Compliant

  • Manufactured from high-grade, FDA-compliant materials
  • Certified to NSF-61 for drinking water system safety
  • Meets all major ASTM and DIN performance standards
  • Proven performance in both residential and commercial systems
Red plastic tubes used for underfloor heating

Merflex PEX OT Oxygen Barrier Tubing Applications

Merflex Oxygen Barrier Tubing is ideal for closed-loop hydronic systems requiring corrosion prevention and long service life.

Common applications include:

Radiant floor heating systems

Baseboard heating loops

Hydronic panel heating

Snow and ice melt systems

Closed-loop boiler systems

Merflex PEX Listing
& Approvals

  • NSF Standard 61: Drinking Water System Components – Health Effects
  • NSF Standard 14: Drinking Water System Components – Performance
  • Plastic Pipe Institute (PPI) Hydrostatic Stress Board, TR-4 Listing, Standard Grade @ 73° F (23° C) HDB 1250 psi, 180° F (82° C) HDB 800 psi and 200° F (93° C) HDB 630 psi.
  • CSA Standard B137.5 – Cross-linked polyethylene (PEX) tubing for pressure applications
  • PEX 5006 rating – The highest chlorine resistance rating possible
  • ASTM F876 – Standard Specification for Crosslinked Polyethylene (PEX) Tubing
  • ASTM F877 – Standard Specification for Crosslinked Polyethylene (PEX) Tubing – Hot and Cold Water Distribution Systems

Get Started with Mercury Plastics

Contact Mercury Plastics today for additional information or to receive a sample of the Merflex Oxygen Barrier Tubing.