EN 14420 Hose Connectors with Clamp Units

The European standard “EN 14420 Hose fittings with clamp units” consists of the following sub-sections published under the same title:

• The standard “EN 14420-1 Part 1: Requirements, fastening and connection types, identification and testing” describes the requirements, fastening and connection types, identification and test methods for hose fittings with clamp units made of rubber/plastic or thermoplastic, preferably for use with flammable and non-flammable products.

This standard for hose fittings includes requirements that, when used properly, ensure that the user or third parties are not exposed to hazards from fire, explosion, or acid burns (e.g., mineral oils or chemicals), and that the environment is protected from pollution and other waste. Maximum operating pressure and temperature values ​​are included in the standard. Before disconnecting quick-connect fittings, the assembly must be at atmospheric pressure.

The scope of this standard is to define the requirements for clamp-type hose fittings that utilize a clamp mechanism to secure the hose tail to the hose end. These fittings are designed for hoses made of rubber, plastic, or thermoplastics and are optimized for the transport of a wide variety of media, including hazardous materials. This standard emphasizes compatibility with both flammable liquids (e.g., fuels, chemicals) and non-flammable liquids (e.g., water, air), making them indispensable in sectors such as petrochemicals, agriculture, manufacturing, and fire safety.

The main objectives of this standard are:

• Ensuring mechanical integrity to prevent leaks, explosions, or connection ruptures under pressure.
• Encouraging interchangeability between fittings from different manufacturers.
• Providing clear guidelines for marking, identification, and quality assurance.
• The standard “EN 14420-2 Part 2: Hose end fittings” describes the hose end requirements for hose fittings used with clamp units according to EN 14420-3 and EN 14420-1. It also specifies the materials for hose fittings with clamp units according to EN 14420-4 to EN 14420-8. The maximum working pressure is 25 bar, and the maximum working temperature is 65 degrees Celsius.

This standard targets hose tails used in assemblies where the clamp unit (EN 14420-3) provides the primary sealing and holding mechanism. It does not cover the entire assembly, but guarantees the compatibility of the hose tail with the assembly. The basic technical requirements are as follows:

• Hose tails must conform to precise geometries to fit standard hose orifices. For example:
• Entry length: The minimum depth that allows the hose to be fully covered without excessive penetration.
• Serrations or ridges: Angled protrusions that grip the hose liner and prevent pulling under pressure.
• Nominal dimensions: Conforms to ISO 4397 standard for hose specifications and provides metric or imperial compatibility.
• The materials have been tested for environmental durability:
• Metal components: Must be resistant to dezincification (for brass) and stress corrosion cracking.
• Surface coatings: Smooth to avoid damaging hose coatings; coating or plating options are available.
• Marking: Each tail must be indelibly marked with the manufacturer's identifier, size, and pressure rating.
• The hose tails within this scope should be based on the following performance criteria:
• Pressure test: Up to 4 times the operating pressure without leakage when assembled.
• Temperature range: Typically -20 degrees to +65 degrees, expandable with special materials.
• Chemical compatibility: Resistance to oils, fuels, and water according to ISO 1436 or EN 1761 standards for specific environments.
• The standard “EN 14420-3 Part 3: Clamp units with bolts or pins” describes the requirements for clamp units for hose fittings according to EN 14420-1, for use with hose tails according to EN 14420-2. The maximum working pressure is 25 bar, and the maximum working temperature is 65 degrees Celsius.

In short, the EN 14420-3 clamp is a clamp with two bolts (or multiple bolts) and a metal band that wraps around a hose over the hose tail. It is designed for:

• To create a 360-degree radial compression seal.
• To resist axial tensile forces.
• It can be attached or removed with simple hand tools (usually a torque wrench).
• It can be reused many times without losing performance.

These clamps are often referred to as safety clamps in the industry because they perform far better than worm gear clamps or single-ear clamps in terms of pressure rating, vibration resistance, and leak prevention.

• The standard “EN 14420-4 Part 4: Flange Connections” describes the requirements for hose tails according to EN 14420-2, flanges with connection sizes of PN 10, PN 16, PN 25, PN 40 (according to nominal size and pressure rating) according to EN 1092-1, and hose fittings with clamp units according to EN 14420-3. The maximum working pressure is 25 bar, and the maximum working temperature is 65 degrees Celsius. Furthermore, flanges can also be used according to the EN 14422 standard.

This standard covers nominal sizes between DN 25 and DN 150 and the following standard pressure classes:

• PN 10: 10 bar. Water, low-pressure air.
• PN 16: 16 bar. Fuel oil, most chemicals, food products.
• PN 25: 25 bar. High-pressure chemicals, steam (limited).
• PN 40: 40 bar. Special applications (rare, exclusive).

The flanges are designed to be bolted directly to their counterparts conforming to EN 1092-1 (steel) or EN 1092-3 (non-ferrous) standards, meaning they integrate seamlessly into plant piping systems.

• The standard “EN 14420-5 Part 5: Threaded Connections” describes the requirements for pipe-threaded hose fittings with clamp units and connecting nuts according to EN 14420-1, and for male pipe-threaded hose ends according to EN ISO 228-1 and EN 14420-2. The maximum working pressure is 25 bar, and the maximum working temperature is 65 degrees Celsius.

This standard explicitly specifies the requirements for fittings (nut-like connectors) and threads in clamp hose fittings. These components facilitate connection to threaded pipes, valves, or equipment using parallel threads compliant with the EN ISO 228-1 standard. This standard applies to hose fittings made of rubber, plastic, or thermoplastic, and the primary objectives are:

• Interoperability: Ensuring that fittings from different manufacturers can be used together without leaks or malfunctions.
• Safety: Critically important in hazardous environments to prevent accidental connection ruptures under pressure.
• Durability: Identifying materials and surface treatments that are resistant to corrosion, abrasion, and thermal stress.
• The standard “EN 14420-6 Part 6: TW tanker couplings” describes the connection combinations, design, materials, and dimensions of tanker coupling hose fittings (TW couplings). Tanker couplings conforming to this standard are designed to connect hoses with fittings for the transport of liquids, solids, and gases, excluding liquids, gases, and vapors. They can be used in a working pressure range of 0,8 bar to 16 bar and in working temperatures from -20 degrees to +65 degrees. For other operating conditions, tanker couplings are subject to agreement. Male and female TW couplings are pressure-resistant plugs. They do not function as a locking device that must be fitted in all cases while the hose assembly is under pressure.

This standard applies to hose assemblies in the following cases:

• The hose is made of thermoplastic materials (single or multi-layered).
• The connection method uses clamp units (safety clamps) according to the EN 14420-3 standard.
• The end connector is one of the following:
• TW (tank wagon) male or female threaded connection (DIN 28450 model)
• VK (female) or MK (male) safety coupling with clamp unit.
• The standard “EN 14420-7 Part 7: Cam-locking couplings” describes the design, material, size, and marking requirements for cam-locking couplings used as connections between hoses and fittings in the conveyance of liquids, solids, and gases (excluding liquid gases and steam). For all aluminum cast coupling sizes and all DN 100 size couplings, the pressure range is between 0,8 bar and 10 bar, within an operating temperature range of -20 degrees to +65 degrees. According to this standard, all other couplings can operate within an operating temperature range of -20 degrees to +65 degrees and a pressure range of 0,8 bar to 16 bar.

In short, this standard covers the following:

• Hose types: Rubber, PVC, thermoplastic (PU, PA, PTFE, composite).
• Nominal dimensions: DN 13-DN 100 (12,7-101,6 mm).
• Maximum working pressure: 16 bar standard (some manufacturers approve 25 bar).
• Temperature range: -40 degrees to +200 degrees (depending on the material).
• Connection type: Cam and groove (EN ISO 14420-7).
• Connection method: Clamp units only (safety clamps), tightening or compressing is not permitted under this standard.
• The standard “EN 14420-8 Part 8: Symmetrical half-coupling (Guillemin system)” describes the dimensions, connection types, material quality, marking requirements, and testing requirements for hose fittings with symmetrical half-couplings (Guillemin system) and movable locking rings, according to EN 14420-2 for hose tails and EN 14420-3 for clamp units, for hose assemblies with a maximum working pressure of 10 bar. Couplings conforming to this standard serve as connections between hoses and fittings for conveying liquids (excluding steam and liquefied gas) and solids (e.g., powders, granules). The operating temperature range is between -20 degrees and +65 degrees.

In short, this standard covers the following:

• Hose types: Silicone, PTFE, EPDM, UPE, and hygienic lined rubber hoses.
• Nominal dimensions: DN 10-DN 100 (9,5-101,6 mm).
• Maximum working pressure: 10 bar (some manufacturers certify 16 bar with reinforced clamps)
• Temperature range: -60 degrees to +200 degrees (silicone/PTFE)
• Connection type: Three-clamp ferrule according to ISO 2852, DIN 32676 and ASME BPE.
• Connection method: Reusable safety clamps (EN 14420-3), compression is not permitted under this standard.
• Measuring devices conforming to the standard “EN 14420-9 Part 9: Measuring devices for TW tanker couplings” are used to check the dimensions of a sealing ring, a curved part, a tensioning ring, and a cap, and to check the angle between the cams of a curved part and the angle between the two gaps of a sealing ring.

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 14420 Hose fittings with clamp units" standard.