PVC, PE and PU Sheath Compounds and LSZH Requirements
How to separate polymer families from smoke, halogen and flame requirements when specifying a conduit covering.
· · 7 min read
Quick answer
PVC, PE-based and polyurethane compounds describe polymer families. LSZH describes a set of low-smoke and halogen performance requirements rather than one polymer. A specific covering is available for technical evaluation only when its grade, construction and finished-product test evidence have been confirmed.
Use requirements, not abbreviations
Begin with continuous and short-term temperature, moisture, oil and chemicals, abrasion, movement, UV exposure, smoke, halogen, flame propagation and any customer standard. No material abbreviation alone establishes suitability.
A practical comparison framework
- PVC is a broad compound family. Use only grade-specific and finished-product data for temperature, flame, oil, UV and chemical performance.
- A PE-based compound may be evaluated only after confirming grade-specific water absorption, environmental stress cracking, friction, flexibility, UV and temperature data.
- A specified polyurethane compound may be considered where abrasion is important. Repeated-motion suitability must be validated on the finished conduit assembly under the intended route and environment.
- LSZH is not a stand-alone polymer or flame rating. State the required smoke-density, halogen or acidity, and flame-propagation test standards and acceptance criteria for the finished construction.
Confirm the complete construction
Record the inner metal construction, covering compound and supplier grade, color, wall thickness, finished O.D. and tolerance, fittings, seals and each required test standard.
Changing the covering can alter finished O.D., mass, stiffness, bend behavior, temperature range and fitting or seal compatibility. Revalidate the complete assembly after a material change.
Frequently asked questions
Which sheath has the highest temperature rating?
There is no reliable ranking from PVC, PE or PU names alone. Use the selected compound data and finished-product tests for the required continuous and short-term temperatures.
Does LSZH automatically mean flame resistant?
No. Specify separate smoke-density, halogen or acidity, and flame-propagation standards with acceptance criteria. The LSZH label alone is not a flame rating.
