EN 13766 Thermoplastic Multilayer (Non-Vulcanized) Hoses and Hose Assemblies

The European standard “EN 13766 Thermoplastic multilayer (unvulcanized) hoses and hose assemblies for the transfer of liquefied petroleum gas and liquefied natural gas - Specification” describes the requirements for two types of thermoplastic multilayer (unvulcanized) transfer hoses and hose assemblies for transporting liquefied petroleum gas and liquefied natural gas. Each type is divided into two classes, one for land-based operations and the other for offshore operations. This standard applies to hose sizes from 25 mm to 250 mm, operating pressures from 10,5 bar to 25 bar, and operating temperatures from -196 degrees to +45 degrees. For offshore LNG hose assemblies, the EN 1474-2 standard also applies.

Hoses should be classified according to their application areas, working pressures, and working temperature ranges as given in the table titled "Pressure and Temperature Range":

• Maximum operating pressure (bar)
• Standing pressure (bar)
• Minimum burst pressure (bar)
• Operating temperature range (degrees)

1 bar = 0,1 MPa. The temperature of the liquid may increase due to pressurization during testing and procedures.

If agreed upon with the manufacturer, lower minimum or higher maximum temperatures are permitted depending on the materials used and the compatibility of these temperatures with the fluid being transported. Other specifications and requirements are listed below.

The manufacturer must verify that the materials used are suitable for the cryogenic liquids to be transported. Hoses must be manufactured as shown in the standard and must consist of the following:

• Class A is for land use.
• An inner wire winding made of stainless steel with the numbers specified according to EN 10088-3 standard.
• A wall consisting of multi-layered film and fabric layers made of thermoplastics that provide both the required properties specified in the table and ensure a complete watertight seal.
• An outer wire coil made of stainless steel with the specified numbers, conforming to the EN 10088-3 standard.
• Class B is for offshore use.
• An inner wire winding made of stainless steel with the numbers specified according to EN 10088-3 standard.
• A wall consisting of multi-layered film and fabric layers made of thermoplastics that provide both the required properties specified in the table and ensure a complete watertight seal.
• An outer wire coil made of stainless steel with the specified numbers, conforming to the EN 10088-3 standard.

According to the agreement between the manufacturer and the buyer, the outer layer may have color identification.

When measured according to EN ISO 4671, the inner diameter values ​​of the hose must conform to the table titled “Dimensions and minimum bending radius”. When tested using the method described in EN ISO 10619-1, the minimum bending radius value must be as given in this table. The hose must not show any signs of permanent deformation in its cross-section, i.e., kinking. When tested according to EN ISO 4671, the measured length tolerance of the delivered hose assemblies must be plus 2 percent or minus 1 percent.

In the world of energy transportation and storage, safety is paramount, especially when dealing with hazardous materials such as liquefied petroleum gas (LPG) and liquefied natural gas (LNG). These materials, stored and transported at extremely low temperatures and pressures, require specialized equipment to prevent leaks, ruptures, or environmental disasters. This is where the EN 13766 standard comes into play, setting a benchmark for thermoplastic multilayer (unvulcanized) hoses and hose assemblies used in the transfer of these cryogenic fuels.

This standard covers thermoplastic multilayer (unvulcanized) hoses and hose assemblies for the transfer of liquefied petroleum gas and liquefied natural gas. It ensures that the hoses meet stringent performance criteria to overcome the unique challenges of LPG and LNG handling. EN 13766 has become a fundamental element for manufacturers, operators, and regulators in the petrochemical and energy sectors.

The EN 13766 standard applies specifically to unvulcanized, multilayer thermoplastic hoses designed for the unloading (storage) of LPG and LNG. It covers hoses with inner diameters between 25 mm and 250 mm, working pressures between 10,5 bar and 25 bar, and service temperatures between -196 degrees (for LNG, liquid nitrogen levels) and +45 degrees. This standard defines two types of hoses:

• Type 1: For LPG transfer, emphasizing resistance to hydrocarbons and moderate cryogenic conditions.
• Type 2: For LNG, requires enhanced low-temperature performance to prevent cracking.

Hose assemblies include couplings, fittings, and reinforcement layers (e.g., textile braids or wire coils) resistant to kinking, vibration, and external impacts. Metal hoses or high-pressure storage hoses covered by EN 1474 and similar standards are excluded.

Compliance with the EN 13766 standard is verified through a series of tests that guarantee mechanical, thermal, and chemical integrity. The key elements of this standard are as follows:

• Material composition: The inner and outer layers must consist of LPG/LNG-compatible thermoplastics such as high-density polyethylene (HDPE) or polyvinylidene fluoride (PVDF). The multi-layer design incorporates barrier layers to prevent gas passage, and the total wall thickness is scaled according to the diameter and pressure rating. Vulcanization (cross-linking with sulfur) is not permitted, which maintains flexibility at cryogenic temperatures.
• Performance tests include the following:
• Hydrostatic pressure test: Hoses are subjected to a pressure test at 1,5 times the maximum allowable working pressure for 5 minutes, followed by a burst test at 4 times the maximum working pressure.
• Low-temperature flexibility: Simulated at minus 196 degrees using mandrel bending tests to check for cracks or leaks.
• Permeability and leakage: Measured for 168 hours to ensure gas diffusion rates are below 0,1 g/m2/day.
• Abrasion and bending resistance: Provides durability in harsh environments such as port operations.
• Assembly and marking: Couplings must be crimped or pressed without damaging the layers and tested for tensile strength. Each hose bears permanent markings: standard identification, type, dimensions, pressure rating, manufacturer code, and batch number.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "EN 13766 Thermoplastic multilayer (non-vulcanized) hoses and hose assemblies for the transfer of liquefied petroleum gas and liquefied natural gas - Specification" standard.