Areas of application and variants of double hose systems Markert Marsoflex Double hose systems: Innovation through many years of research and development2 Innovation for more safety when moving water-polluting, toxic, combustible and other critical media Contents 1. Area of application 2. Function 3. Possible monitoring techniques 4. Examples of monitoring with signallers 5. Sizes and versions 6. References / application examples 7. Sample application: tanker truck offloading 8. Why Markert Marsoflex 9. Contacts3 1. Area of application Hose assemblies are used everywhere in industry. Whether for simple fuels or highly aggressive chemical media, with the proper hose materials any fluid can be transported through hose assemblies. Regular inspection of hose assemblies is a must. German regulations require that hose assemblies that are part of systems requiring monitoring must be regularly inspected. As a rule, this means that hose assemblies are subject to repeat inspection at least once annually. For this repeat inspection, the hose assembly must be tested on a test stand. This requires removing the hose from the system. But what if special system features make this difficult or impossible? What if even the smallest leaks can have devastating consequences for people, the environment and the system? In such cases, double hose systems are the right solution, because with these the fluid-conducting hose can be additionally secured and/or monitored. Therefore, double hose systems are often used when transporting water-polluting, toxic, combustible and other critical media. Frequent applications are transporting: • Aggressive media such as hydrochloric acid, caustic soda, sulfuric acid and hydrofluoric acid • Combustible fluids and gases such as ethanol, petrol, kerosine, diesel and heavy oil • Other media such as transformer oil and basic chemicals This White Paper explains how double hose systems work. It also provides an overview of monitoring technology possibilities. Finally, it covers possible application areas and the respective solutions for them, since double hose systems are typically tailored to their applications. For this reason, Markert has decided not to conduct a general type examination, but instead inspects each double hose system individually as per the Pressure Equipment Directive, with permitting by individual approval, for example by TÜV. Only in this way can double hose systems be configured entirely for their system conditions.4 2. Function Markert Marsoflex Double hose systems consist of two integrated hose lines. The inner hose is completely monitored, providing ideal conditions for safe use as a media transport line. The inner and outer hoses are individually designed for the properties of the medium being transported. The connections are also specifically designed for the geometry required on the system side. A special connector is made to customer specifications for assembling the double hose system. The monitored space is located between the inner and outer hose. Monitoring devices on the outside hose can detect pressure increases caused by leakage of the inner hose, which carries the media, and trigger a visual or acoustic signal. The necessary safety measures can thus be taken immediately. If the connection is designed so as to fit within the monitored space (see figure below), the signalling device can also indicate a leak at the connection. With regard to the selection and configuration of hose materials, the following criteria and parameters apply as a rule: • Flexibility of the hose (bending radius) • Abrasion resistance of the outer cover • Fire resistance of the system • Pressure resistance • Vacuum resistance • Surface characteristics (cleanability) monitored space connection according to customer requirements inner hose Double hose connection with attachment in the monitored space5 3. Possible monitoring techniques Often, the safety provided by the double hose system is sufficient in and of itself. Detectors can be used in addition to provide ongoing monitoring. The following systems are commonly used: • Monitoring of the non-pressurised interior by lateral measurement connections (recommended variant) • Monitoring of the vacuum interior by lateral measurement connections in combination with a vacuum pump • Monitoring of the pressurised interior by lateral measurement connections in combination with a pressure pump 4. Examples of monitoring with signallers As a rule, the following kinds of sensors are used for monitoring: • Transparent outer hose: no sensor necessary, damage is identified by visual check. • Pressure gauge mounted on the measurement connection: value is read. • Mechanical or electrical sensor: visual or acoustic signal is given.6 5. Sizes and versions Double hose systems from Markert Marsoflex are available in the following sizes and materials. Since the system is modular, other configurations in addition to the variants shown here are available at the request of the customer. DN Media contact Inner hoseOuter hose Special configura- tion 8 EPDM NBR UPE FEP PTFE, smooth PTFE, corrugated PFA Silicone … EPDM NBR UPE PTFE FEP Polypropylene Silicone Stainless-steel braid … Heat protection Abrasion protection (stainless steel or synthetic coil) 10 15 25 32 38 50 65 80 1007 6. References / application examples Double hose systems from Markert Marsoflex have been used successfully for decades in many applications. Below are some unusual and demanding projects that give an idea of the versatility of the product. Application areaSpecial featureProduct variant Fuel hose for conven- tional marine engines Prevention of machine-room fire in the event of hose leakage ―› Markert Marsoflex Double hose system for heavy fuel oil (HFO) (inside: PTFE/metal braid/heat protection/ outside: PTFE/syntheticbraid/heat protection) ―› Markert Marsoflex Double hose system for diesel (MDO) (inside: PTFE/metal braid/ outside: rubberised textile fabric hose/heat protection) Fuel hose at high pressure for dual-fuel methanol marine engines Detection of possible hose leak- age with immediate emergency shut-off ―› Markert Marsoflex Double hose system (inside: high-pressure hydraulic hose NBR / outside: PTFE/metal braid/ heat protection for methanol) ―› Markert Marsoflex Double hose system for diesel (MDO) (inside: PTFE/metal braid/ outside: rubberised textile fabric hose/heat protection) Automatic filling of engines with consumables such as coolant, engine oil, transmission fluid, brake fluid, air conditioner coolant or windshield cleaner ―› Markert Marsoflex Double hose system Inside: DN 6 / Outside: DN 25 Inside: DN 19 / Outside: DN 38 with abrasion protection ―›8 Application areaSpecial featureProduct variant Transport of hazardous fluids, in this case transformer oil, from 0°C to 100°C, multiple hoses can be linked and the monitored spaces connected with each other. Main application: Filling and draining trans- formers with transformer oil for protecting people and the environment in the event of a hose break Design: Inside: NBR elastomer hose / Outside: Composite hose, blue polypropylene, max. 80°C Alternative: Inside: Smooth PTFE hose / Outside: Composite hose, red PTFE/ FEP, max. 100°C With the transparent outer hose, defects and any media leakage from the inner hose become visible. Double hose system,- frequently used for various chemicals Product delivery when loading and unloading stations do not have a collecting basin with sep- arator. Tip: Building a collecting basin for the use of simple hoses includ- ing permitting is many times more expensive than an intelli- gent double hose system! Inside: Elastomer hose with different hose cores or PTFE hose Outside: Composite red PTFE/FEP or composite blue polypropylene9 7. Sample application: tanker truck offloading Double hose connection with attachment in the monitored space Left: System side with double hose clamp and flexible double hose con- nection to the filling unit (buffer tank). Double hose assembly monitoring by sensor connection. Right: Filling side with double hose swivel-mounted on articulated arm. Connection to tank truck by dry couplings (optionally fitted with quick- release coupling). Monitoring likewise by sensor connection. Double hose assembly, DN 50 Length 20 m Double hose assembly, DN 50 Length 5 m Filling hose with articulated arm Sensor connection Filling unit Sensor connection Tank truck optionally with quick-release coupling Dry coupling female part Dry coupling male partNext >