MASTERFLEX – Technische Schläuche & Verbindungen

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MASTERFLEX – Technische Schläuche & Verbindungen
MASTERFLEX – Technische Schläuche & Verbindungen

Technical information about hoses

Do hoses have to have a CE marking? When may a hose be used for transporting food? Which regulations apply in Europe and which in the USA? Answers to these and more questions can be found here.

Technical information - everything that is important at a glance!

Are you looking for technical information? Here you will find information on all technical aspects of our hoses and connection solutions - as well as standards and regulations, instructions, electrostatics notes, a chemical resistance list and the Technical Appendix.

TRGS 727 - Avoidance of ignition hazards due to electrostatic charges

The Technical Rule for Hazardous Substances - TRGS 727 for short - has been valid since 26.04.2016 for the assessment and avoidance of ignition hazards due to electrostatic charges in potentially explosive atmospheres as well as for the selection and implementation of protective measures to avoid these hazards.

It has replaced and updates the previous TRBS 2153. With TRGS 727, there have been changes in the measurement procedures for technical hoses in potentially explosive atmospheres. We have been following this development for a long time and are therefore also familiar with the new measuring methods.

A distinction is now made between pneumatic and aspirative conveying. Surface or leakage resistance remains the definitive unit for determining the area of application in aspirative conveying. From now on, resistivity will be the definitive unit for determining the area of application in pneumatic conveying.

Important: Our electrically conductive and antistatic hoses can still be used without hesitation!

They comply with the new standards of TRGS 727, and their suitability can be verified with appropriate certificates. From a technical point of view, therefore, nothing has changed with regard to the products you are used to.

Download declaration of conformity TRGS 727

Electrostatic and TRGS

During the transport of solid, liquid or gaseous media, a so-called "interfacial potential" is built up due to friction on the inner wall of hose lines, for example. Depending on the degree of charging, this leads to sparking, electrical breakdown or, under certain circumstances, to the ignition of ignitable substances. In addition to the intensity of contact (friction) between the medium and the hose wall, the "dielectric constant" of the hose and flow medium is decisive for the level of chargeability. This is regarded as a measure of the polarizability. Even conductive substances become charged if they are not grounded.

A number of guidelines and regulations exist for the assessment and avoidance of ignition hazards and the protective measures to be taken. At this point, we refer primarily to the Technical Rule for Industrial Safety, TRGS 727 "Avoidance of ignition hazards due to electrostatic charges", which is determined by the Committee for Industrial Safety (ABS) and published by the Federal Ministry of Labor and Social Affairs in the Joint Ministerial Gazette. TRGS 727 replaces and updates the previous TRBS 2153.

Masterflex products also comply with the relevant Union harmonization legislation: Directive 94/9/EC (until April 19, 2016) and Directive 2014/34/EU (from April 20, 2016).

The surface resistance of hose wall materials can be reduced to values between 103 and 104 ohms by incorporating conductive additives. These conductive additives (e.g. conductive carbon black) form a network of contacting conductive particles in the plastic (volume conductivity). However, due to the additives, these plastics are aus-
timately available in black.

Another possibility is the incorporation of antistatic additives, whereby a surface resistance of <109 ohms is achieved and the transparency of the base materials is maintained. There are antistatic additives that achieve a corresponding surface resistance by binding the moisture in the air to the hose surface. However, this embodiment has the disadvantage that when dry powders, for example, are conveyed, poor or insufficient antistatic properties result from the lack of air moisture. In addition, the buildup of suitable surface resistance can be impeded by the abrasion that occurs during use
. For this reason, antistatic hoses should be used in the zones/applications permitted for this purpose, preferably equipped with permanently effective antistatic additives that do not depend on an additional external component.

For subordinate applications, such as in Zone 1 for "gases and liquids with low conductivity" and in Zone 21 for "non-flammable dusts/bulk materials", spiral/clip hoses with discharge of electrostatic charges can also be used on Masterflex hoses with a wall material where there is a surface resistance > 109 Ohm. In this case, however, care must be taken to ensure a spiral/clip pitch < 30 mm and an overlap of the spiral < 2 mm in order to be able to achieve a dissipative effect.

In all the applications described above, both spiral/clip ends of the hose must always be connected to the connector in a conductive manner. Information on the possible applications of Masterflex hoses is given in the relevant catalog data sheets under Properties.

Limits and definitions

Electrostatic chargeable are generally:

  • Hose assemblies with wire helix
  • solids with a surface resistance >109 Ohm
  • all non-grounded objects of conductive materials

Electrostatic chargeable are generally:

  • all solid and liquid substances with a surface resistance below the above mentioned limit resistances
  • all conductive substances that are grounded.

In practice, this means with regard to
uses of hose assemblies with
wire helix/clip:

1. when handling "low conductivity gases and liquids" in Zone 1, and "non-flammable dusts/bulk solids" in Zone 21, spiral/clip hoses can be used whose wall surface resistance is >109 ohms, the spiral/clip pitch is <30 mm, and the spiral/clip overlap is <2 mm. In addition, when installing the hoses, make sure that both
spiral/clip ends are grounded to the dissipative connection parts.

2 Increased protection is achieved when using non-rechargeable hoses, e.g. antistatic hoses with a surface resistance <109 Ohm, where the exposed spiral/clip ends are also connected to earth with the conductive
connection parts.

3. electrically conductive hoses with a surface resistance <106 Ohm offer optimum safety. For safety reasons, these hoses should also have a grounding connection between the exposed wire ends and the conductive connection pieces. Tested Masterflex hoses with the suffix "EL" fully meet these requirements.

The determination of the surface resistance depends on the respective measuring method and, in the case of non-conductive solids, is carried out in accordance with DIN IEC 60093 / VDE 0303, Part 30 (Test methods for electrical insulating materials, volume resistivity and surface resistivity of solid, electrically insulating materials).

For rubber and plastic hoses and hose assemblies, DIN EN ISO 8031 - Rubber and plastic hoses and hose assemblies, describes the determination of electrical resistance.

This standard describes:

  • Procedures for hoses with conductive inner layers (e.g. the measurement procedures for the hose types: Master-Clip, ...).
  • Procedures for hoses with conductive outer layer
  • Procedures for hoses made of continuous conductive material mixtures (e.g. the measuring procedures for the Masterflex hose types with the suffix "EL")

The addition of conductivity additives or antistatic agents reduces the mechanical properties of the material (e.g. abrasion and tear resistance) and thus shortens the service life. The information is based on internal and external field tests
as well as the currently valid regulations. It serves as a guideline for the use of Masterflex hose types in potentially hazardous areas and does not claim to be complete.

The catalog information regarding surface resistance is based in part on official test results, information from our raw material suppliers
and internal measurements. In case of doubt, we recommend that users test hoses under operating conditions or similar conditions before final installation.

Operating instructions of the Masteflex

  • Instruction manual: Grounding clip hosesIn order to avoid electrostatic ignition hazards, proper grounding of the hoses must be performed during assembly and installation. In this case, the metal clamping profile must be grounded on both sides of the hose. Download 227 KB
  • Operating instructions: Sealing screw connectionsIn these operating instructions, we will show you how to quickly and easily bond PU hoses tightly with the matching Masterflex connecting parts. To achieve an optimum result, simply go through these instructions step by step. Download 4 MB

REACH - the EU chemicals regulation

REACH stands for Registration, Evaluation, Authorization and Restriction of Chemicals. REACH is a European Union regulation that was enacted to improve the protection of human health and the environment from the risks that can be posed by chemicals, while at the same time increasing the competitiveness of the EU chemical industry.

In principle, REACH applies to all chemical substances used in industrial processes. The REACH system is based on the principle of industry ownership. Within the scope of application, only chemical substances that have been registered beforehand may be placed on the market.

Masterflex SE is aware of the requirements of the REACH regulation in principle and fulfills its obligations to implement REACH in accordance with the law. We have initiated communication with our upstream suppliers and, as a distributor rather than a manufacturer, are dependent on their information. Our suppliers have confirmed to us that they have pre-registered or intend to register their substances. Should substances fall under the REACH exemption, we will be informed immediately.

Masterflex SE hereby declares on the basis of the available supplier data that the distributed products meet the requirements of the REACH Regulation (EC) No. 1907/2006.

About the declaration of conformity to the REACH regulation

 

Other standards and regulations

The CE marking (Conformité Européenne) means "conformity with EU directives" and is a marking under EU law for certain products related to product safety.

By affixing the CE marking, a manufacturer confirms that its product complies with one or more applicable European directives within whose scope the product falls in each case. This is now mandatory for certain product groups.

CE-marked products are subject to the unrestricted movement of goods in any EU country, while products requiring marking may no longer enter the movement of goods after a certain specified date (example: the date for machines is 01.01.1995).

In general, Masterflex SE hoses do not fall under product groups subject to mandatory labeling, since according to the definition of the EU Machinery Directive 89/392/EEC, hoses are neither classified under machinery, safety components or products according to the Low Voltage and EMC Directives, the Medical Device Directive, etc., but are considered components that do not qualify for CE labeling.

Therefore, hoses must not be marked and corresponding declarations of conformity (manufacturer's declarations) must also not be issued by Masterflex SE. Safety data sheets according to DIN EN 292 and works certificates according to EN 10204, which certify the properties of Masterflex products, can be provided if required.

All information provided by us is general information which, due to individual application possibilities, different on-site operating conditions and design variation possibilities, does not permit any commitment or guarantee.

In order to be allowed to use hoses in the food sector, they must meet the corresponding "food regulations or approvals". The polyurethane hose types produced by Masterflex meet these requirements.

The raw materials used to manufacture Master-PUR Food hoses comply with the following food law conditions:

  • EU: The hoses of the Master-PUR Food series comply under certain conditions with the requirements of Regulation (EU) No 1935/2004 as well as Regulation (EU) No 10/2011 and 1282/2011 or the Food and Feed Code (LFGB, as of 15.03.2012) and the Consumer Goods Ordinance (as of 13.12.2011).

More Information

The raw materials used for the production of Master-PUR Food A hoses comply with the following food law conditions:

  • EU: The Master-PUR Food A series has been tested and approved by an independent institute. The monomers used in the production are listed in the Bedarfsgegenständeverordnung (German Commodity Ordinance) in the version published on 23.12.1997 (BGBl. 1998 l p.5), last amended on 23.09.2009 (BGBI. I p.3130). The monomers used are listed in the annexes to Directive 2002/72/EC, as amended by the latest amending directives 2007/19/EC of March 30, 2007 and 2008/39/EC of March 7, 2008, and EC Regulation 975/2009 of October 20, 2009. The additives used are listed in Annex III of Directive 2002/72/EC as amended by the latest amending Directives 2007/19/EC, 2008/39/EC and EC Regulation 975/2009 of 20.10.2009. Please refer to the test certificate H-192339K-10-Bg for the conditions of the requirements from the regulations. The certificate will be presented upon request of the user.

More information

In order to be allowed to use hoses in the food sector, they must meet the corresponding "food regulations or approvals". The polyurethane hose types produced by Masterflex meet these requirements.

The raw materials used to manufacture Master-PUR Food hoses comply with the following food law conditions:

  • USA: The raw materials and additives used (except stabilizers) are listed in the FDA's 21 CFR (Code of Federal Regulations) § 177.2600 "Rubber articles intended for repeated use" dated 01.04.2009. The antioxidants/stabilizers used are listed in FDA 21 CFR § 178.2010 "Antioxidants and/or stabilizers for polymers".

More Information

The raw materials used for the production of Master-PUR Food A tubing comply with the following food regulations:

  • USA The raw materials and excipients used (except stabilizers) are listed in FDA 21 CFR (Code of Federal Regulations) § 177.2600 and 21 CFR § 178.2010 "Rubber articles intended for repeated use" dated 04/01/2009 and in the Effective Food Contact Substance Notifications (FCS) list.

More Information

DIN EN ISO 8031

Rubber and plastic hoses and hose assemblies

  • Determination of electrical resistance and electrical conductivity DIN IEC 60093
  • Test methods for electrical insulating materials Spec. volume resistance and Spec. surface resistance of solid, electrically insulating materials DIN VDE 0303-8
  • VDE regulations for electrical tests of insulating materials; assessment of electrostatic behavior

DIN 54345-1

Testing of textiles

  • Electrostatic behavior, determination of electrical resistance values

DIN 4102-1

  • Fire behavior of building materials and components

DIN EN ISO 6941

  • Textiles, burning behavior Measurement of flame spread properties of vertically arranged samples

DIN 66083

  • Characteristic values for the burning behavior of textile products - textile fabrics for workwear

DIN ISO 4649

  • Elastomers or thermoplastic elastomers - Determination of abrasion resistance by means of an instrument with rotating cylinder drum

DIN 53752

Requirements for spiral hoses made of TPU

DIN 53752

Testing of plastics

  • Determination of the coefficient of linear thermal expansion

DIN 53505

Testing of rubber and elastomers

  • Hardness test according to Shore A and D

DIN 53359

Testing of artificial leather and similar fabrics

  • Fatigue buckling test

DIN 53863-2

Testing of textiles

  • Abrasion tests of textile fabrics, circular abrasion test (Schopper test)

DIN ISO 34-1

Elastomers or thermoplastic elastomers

  • Determination of tear propagation resistance - Part 1: Strip, angular and arc-shaped test specimens

DIN 53504

Testing of rubber and elastomers

  • Determination of tear resistance, tensile strength, elongation at break and stress values in the tensile test

DIN EN ISO 1183-1

Plastics

  • Methods for the determination of density of non-foamed plastics - Part 1: Immersion method, liquid pycnometer method and tritation method

DIN EN ISO 4892

Plastics

  • Artificial irradiation or weathering in equipment - Part 1: General guidance

Pressure and negative pressure (vacuum)

All data are the result of internal tests and trials in accordance with international standard recommendations and refer to a medium and ambient temperature of +20 °C. Deviating temperatures can change the pressure and vacuum data. Due to the design, a change in length of individual hose types is possible due to the influencing variables of pressure, vacuum, medium and ambient temperature.

The operating pressure, the test pressure and the burst pressure are determined in accordance with DIN EN ISO 7751.

 

In the vacuum strength test, the hoses are laid in a 90-degree bend while maintaining the minimum bending radius and subjected to negative pressure until they showed signs of indentation or collapse. Taking into account a generally accepted safety factor, the determination of the permissible negative pressure in continuous operation is carried out.

The determination of the negative pressure specifications for Masterflex hoses is based on DIN 20024, item 15.

The pressure drop is the air resistance in a hose or pipe system.

When designing a ventilation system, the unavoidable air resistance must be taken into account. To simplify the determination of pressure loss, the specific pressure losses of Masterflex hoses can be taken from diagrams.

The data are mean values for hoses in the stretched condition at +20 °C.

To the technical appendix