UL 1660 covers liquid-tight flexible nonmetallic conduit, often abbreviated LFNC, used for electrical raceway applications.
For manufacturers, labs, and buyers, this is usually a product-verification reference rather than one isolated bench test. If you need help matching the cited requirement to a practical equipment path, contact our team.
UL 1660 Liquid-Tight Flexible Nonmetallic Conduit
UL 1660 is a UL safety standard for liquid-tight flexible nonmetallic conduit, often abbreviated LFNC, used for electrical raceway applications. It is used where electrical raceway products need to meet a recognized product requirement.
The exact edition, product type, trade size, construction, and marked use condition should control the inspection and test setup.
Quick Definition
Document type: UL product safety standard.
Main focus: liquid-tight flexible nonmetallic conduit.
Primary equipment path: dimensional tools, bend or flexibility fixtures, conditioning chambers, liquid exposure setups, temperature-conditioning equipment, and reporting software.
What This Standard Covers
UL 1660 addresses product-level requirements for liquid-tight flexible nonmetallic conduit, often abbreviated LFNC, used for electrical raceway applications, including practical checks around construction, dimensions, markings, and performance where required.
Because the standard is product-focused, the equipment path depends on the characteristic being checked rather than one universal test machine.
Why This Standard Matters in Testing
Electrical raceway products protect and route conductors, so product consistency and safety requirements matter in installation and certification workflows.
When UL 1660 is cited, the lab setup should match the exact product form, trade size range, finish or material system, and edition named by the requirement.
Common Materials, Product Types, or Applications Covered
The standard is focused on electrical raceway products and related components.
Common material or product areas: nonmetallic flexible conduit bodies, liquid-tight conduit constructions, conduit samples by trade size, and related raceway configurations.
Common application questions: whether the product meets the construction, dimensional, marking, and performance expectations named by the cited UL requirement.
Common Test or Verification Workflow
A typical workflow starts with product identification and sample selection, followed by inspection, dimensional measurement, conditioning, and any method-specific performance checks.
The final setup should be driven by the exact UL edition and the product configuration being evaluated.
Workflow focus: product construction, dimensional verification, marked ratings, conditioning, and reporting.
Equipment Commonly Used for This Standard
UL 1660 work can involve several equipment families because the product may need dimensional, mechanical, environmental, or finish-related verification.
Common equipment families: dimensional tools, bend or flexibility fixtures, conditioning chambers, liquid exposure setups, temperature-conditioning equipment, and reporting software.
Selection focus: confirm trade size range, material or coating system, product type, marked use conditions, and exact cited edition before selecting equipment. If you are comparing equipment configurations for this workflow, request a quote.
How to Read This Designation or Revision
UL 1660 is the fixed UL designation for this product standard.
A citation may include an edition or revision date, and that version should control the test setup and reporting language.
Related Standards, Methods, or Frameworks
UL 360 covers liquid-tight flexible metal conduit, while UL 514B is commonly relevant for conduit fittings. They should not be treated as interchangeable with UL 1660.
Need Help With UL 1660 Equipment Planning?
If your requirement cites UL 1660 and you need to define the right equipment scope, request a quote.
