GB/T 40068-2021 Electrofusion welding sleeve (tape) for thermal insulation pipeline
1 Scope
This standard specifies designation, product forms, specifications and dimensions, requirements, test methods, inspection rules, marking and packaging, transportation and storage of high-density polyethylene (HDPE) electrofusion welding sleeve (tape) for thermal insulation pipelines.
This standard is applicable to electrofusion welding sleeves (tapes) intended for joint coating of polyurethane thermal insulation pipeline with external HDPE protection.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1040.1 Plastics - Determination of tensile properties - Part 1: General principles
GB/T 1408.1 Insulating materials - Test methods for electric strength - Part 1: Test at power frequencies
GB/T 1633 Plastics - Thermoplastic materials - Determination of Vicat softening temperature (VST)
GB/T 3280 Cold rolled stainless steel plate, sheet and strip
GB/T 3682.1 Plastics - Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics - Part 1: Standard method
GB/T 6146 Test method for resistivity of precision resistance alloys
GB/T 7141 Plastics - Methods of heat aging
GB/T 8804.3 Thermoplastic pipes - Determination of tensile properties - Part 3: Polyolefin pipes
GB/T 10612 Industrial plate screens - Thickness below 3 mm - Round and square holes
GB/T 18475 Thermoplastics materials for pipes and fittings for pressure applications - Classification and designation - Overall service (design) coefficient
GB/T 23257 Polyethylene coating for buried steel pipeline
GB/T 29046 Test methods of technical specification for pre-insulated directly buried district heating pipes
GB/T 29047 Prefabricated directly buried insulating pipes and fittings with polyurethane foamed-plastics and high-density polyethylene casing pipes
GB/T 31838.2 Solid insulating materials - Dielectric and resistive properties - Part 2: Resistive properties (DC methods) - Volume resistance and volume resistivity
ISO 6721-1 Plastics - Determination of dynamic mechanical properties - Part 1: General principles
ISO 6721-4 Plastics - Determination of dynamic mechanical properties - Part 4: Tensile vibration - Non-resonance method
EN 489 District heating pipes - Preinsulated bonded pipe systems for directly buried hot water networks - Joint assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene
NACE RP0303 Standard recommended practice field - Applied heat - Shrinkable sleeves for pipelines: application, performance, and quality control
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 23257, GB/T 29046, GB/T 29047 and the following apply.
3.1
split polyethylene electrofusion welding sleeve
electrofusion welding sleeve of a construction type in which the HDPE sleeve (sheet) is split from the electrofusion welding net
Note: Split PE electrofusion welding sleeves are divided by substrate structure into seamless type and butt weld type.
3.2
integral plate type polyethylene electrofusion welding sleeve
structural member consisting of a HDPE sheet, the inner surface of which is thermal bonded by its girth (ends) and embedded into a special electrofusion welding net by a certain process to form a joint coating material that, as electrically heated, can be fused integrally with the outer casing of thermal insulation pipe to provide waterproof protection
3.3
polyethylene electrofusion welding tape
connecting structural member consisting of a HDPE strip which is thermal bonded and embedded in a special electrofusion welding net
3.4
substrate
HDPE plate, strip or tube (sleeve) material required for producing electrofusion welding sleeve (tape)
3.5
electrofusion welding net
electric heating element which is made of thin-walled nickel and chromium stainless steel plates by mechanical process of high-pressure punching, and is intended for processing electrofusion welding sleeve (tape) and outer casing of pipe
4 Designation
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Designation
5 Product forms, specifications and dimensions
6 Requirements
7 Test methods
8 Inspection rules and items
9 Marking and packaging
10 Transportation and storage
