When To Use Flexible Metal Hose?
Flexible Metal Hose offers the solution where non-rigid connections for conveying liquids, gases and semi-solids are needed and offer a number of advantages including high strength, resistance to high or low temperature extremes, and corrosion resistance. It helps protect your equipment by absorbing vibrations and noise, connects misaligned rigid piping, connects moving parts of machinery or equipment, and is practical for hooking up frequently moved or dismantled equipment.
Types of Flexible Metal Hose?
Flexible Metal Hose is manufactured in three basic styles: Corrugated Flexible Metal Hose, Interlocked Flexible Metal Hose, and Square locked Flexible Metal Hose.
A wide range of sizes from 1/4″ I.D. (inside diameter) to 24″ I.D., with special sizes available upon special request.
The choice of metal hose is wide: bronze, carbon steel, stainless steel, monel, inconel, hastelloy with optional SS, or Bronze wire braid.
End fittings include male and female pipe threads, unions, flanges, flared tube fittings or other specially designed connectors.
Why Use Flexible Metal Hose?
Flexible Metal Hose is frequently used in piping situations where:
There is a need to absorb the heat or pressure-induced expansion of the pipe system;
There is a need to compensate for misalignment, or to allow lateral movements of the system during exploitation;
High temperature fluids or gases have to be safely conveyed through a system under high pressure or under vacuum conditions;
When a system is subjected to a vibration there is a need for special products like corrugated metal hose;
When a system is exposed to high external heat, corrosion, or heavy or rough handling.
Where Flexible Metal Hose is Used?
With its ability to meet high demands for conveying hot and cold substances, this modern technology has the following major areas of application:
Electrical industry and mechanical engineering: as a protective hose for electrical cables or light conductors.
- As a suction, conveying and coolant hose, e.g. when conveying and transporting liquid gas.
- Automotive industry: as an exhaust gas hose that acts as a vibration decoupler in exhaust systems.
- As a ventilation hose in technical building equipment.
- Steel industry.
- Measuring and control equipment.
- Medical equipment.
- Aviation and space travel.
- Reactor technology.
- Regenerative energies (solar heat, wind turbines, etc.)
When To Use Flexible Metal Hose?
Flexible Metal Hose is used as a last resort. The decision of which hose type to buy depends on the application for which the hose is being used. Generally, there are eight factors that should alert you to consider using flexible metal hose:
1. Temperature Extremes
If either the temperature of the media going through the hose or the surrounding atmospheric temperature is very cold or hot, metal may be the only material that can withstand the temperature extremes.
2. Chemical Compatibility
Metal hose can handle a wider variety of chemicals than most of the other hose types. If the hose will be exposed to aggressive chemicals (either internally or externally), metal hose should be considered. Stainless steel exhibits good resistance to many common chemicals and special alloys may be used for added corrosion resistance. Please note that special care should be taken to make sure that all assembly components are resistant to chemical attack, both from the media conveyed and the environment.
3. Permeation Concerns
Non-metal hose is susceptible to having gases permeate through the hose wall and into the atmosphere. Flexible Metal Hose, on the other hand, does not allow permeation when properly fabricated. If containing the gases inside the hose is important, metal hose may be required.
4. Potential for Catastrophic Failure
When a flexible metal hose fails, it usually develops small holes or cracks. Other hose types tend to develop larger cracks or come apart completely. In non-metallic hoses, barbed fittings are typically held onto the hose ends using clamps or crimped collars. Because fittings are welded to metal hose, fitting retention problems are nearly non-existent. If a sudden failure of the hose can be catastrophic, a metal hose may help minimize the effects of a failure by leaking product at a slower rate.
5. Abrasion and Over bending Concerns
To prevent abrasion and over bending, a metal hose can be used as a protective cover over wires or even other hoses. Stripwound hose can be very abrasion resistant, making it ideal for use as protection to corrugated hose from either abrasive media or external damage. Stripwound hose can also be applied to the outside of a corrugated hose to prevent it from overbending. Bending a corrugated hose is one way to excessively fatigue the metal hose of an assembly. However, stripwound hose cannot be overbent without pulling the hose apart, making it an excellent bend restrictor when installed on a corrugated assembly.
6. Fire Safety
Other hose types will melt when exposed to fire while flexible metal hose maintains its integrity up to 1200º F. Flexible corrugated hoses are usually all-metal (unless a fitting contains a non-metallic seal), which makes them naturally fire-resistant. Low permeation and fire resistance make corrugated hoses the preferred choice for barge loading and unloading applications, or any application where the hose may be exposed to an open flame.
7. Achieving Full Vacuum
Under full vacuum, flexible metal hose maintains its shape while other hose types may collapse. The corrugations in a metal hose give it excellent hoop strength, which gives it the ability to handle a full vacuum. Nonmetallic hoses must use helix wires to improve their vacuum rating, but collapse is still possible.
8. Flexibility in Fitting Configuration
Any weld-able fitting can be incorporated into a corrugated hose assembly, and in any configuration, while other hose types require special shanks and collars. This can be a benefit over other hose types that would require multiple threaded connections to connect several hoses together. Every threaded connection is a potential leakage point, so every welded fitting eliminates a leakage point and can facilitate installation.
Source: China Flexible Metal Hose Manufacturer – Yaang Pipe Industry Co., Limited (www.ugsteelmill.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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