Metal hoses are flexible corrugated tubes used to absorb misalignments in the systems, thermal expansion, and contraction of pipes and vessels. The main shape differences between bellows and hoses are length to nominal diameter ratio is over 3 and the convolution height to pitch ratio is low. KLINGER Turkey standard hose material is 316L and standard braid material is 304ss. KLINGER Turkey manufactures braided and unbraided hoses from DN4 to DN150. Compressing the tube to give it a close pitch profile will increase the flexibility of the hose. It is very important to make sure that the hose longitudinal weld is at least as strong as the base material itself. Burst pressure tests are commonly done to ensure this.
Advantages of a Metal Hose
Advantages of a metal hose over similar products are:
- High physical strength
- Fire resistant
- Good corrosion characteristics
- Resistance to penetration and damage
Metal Hose Movement Modes
- Static Installations: When the flexible hose is used to connect pipework out of alignment and remain in a static position.
- Occasional Flexing: When hose flexes occasionally, such as during manual handling.
- Constant flexing: When the hose flexes continuously, usually on moving machinery.
- Vibration: High frequency, low amplitude movement.
Manufacturing of Hoses
Metal hoses are manufactured in one continuous manufacturing line;
- Coils are mounted on unwinding units and sheets are unwound,
- Sheets pass through several openings to get the final tube shape,
- Sheets are longitudinally welded,
- Corrugations are formed,
- Corrugations are cleaned from oil and grease,
- The final product is ready for testing.
A plain corrugated metal hose will try to elongate when pressurized above a certain level. This is due to the pressure thrust of the hose. To restrain this, the hose is fitted with an external wire braiding which can be either a single or double-layer according to design conditions. Braids lower the flexibility of the hose while drastically increasing its pressure resistance. Braids also offer external protection to the hose.
Braid design depends on:
- Number of wires
- Wire diameter
- Wire mechanical strength
- Angle between wires
Intermetalflex tests all hoses after manufacturing and after fittings are attached. Testing is performed underwater by filling the hoses with nitrogen and observing for bubbles. Also, the pressure inside the hose is monitored digitally for pressure drop.
Braided Hose – Burst Pressure Test
Braided hoses are selected randomly and pressurized until they burst. This test ensures braid, hose, and welding quality. The safety factor is 3 or 4 depending on the industry served.
Braided and Unbraided Hose – Cycle Life Test
Intermetalflex hoses are subjected to cycle life tests as required per standards or customers. Our hoses pass strict cycle life and bening radius requirements of EN10380.
Framed Heat Exchanger Hoses
Framed heat exchanger hoses manufacturing process;
- Coiled stainless steel wires are unciled and cut to desired lengths automatically,
- Cut wires are placed on an automatic welding table in the desired configuration,
- Frames are rolled and spot welded to give their final shape,
- Hoses are wrapped around the finished frame,
- Hoses in boilers.
Advantages of using Metal Hose in Heat Exchangers
There are many advantages of using a metal hose in heat exchangers;
- High surface area compared to rigid pipe,
- Thin walls (less conduction loss),
- Turbulent flow inside the hose increases heat transfer,
- Less weight compared to the rigid pipe.
Multilayer insulation of metal hoses consists of:
- High temperature resistant inside layer,
- The middle layer of standard cross-linked PE insulation,
- Weather and UV resistant protective outer layer,
- Resistant to: 150oC continuous temperature and 175oC temporary temperature,
- Special rough surface protects against damages due by birds or mice.
Metal Hoses Manufactured by KLINGER Turkey
- Standard Flexible Metal Hoses
- Large Diameter Flexible Metal Hoses
- High-Pressure Flexible Metal Hoses
- Ultra-Flexible Hoses
- Solar Hoses
- Boiler Hoses
- Ht Composite Pre-insulated Hoses
- Heat Exchanger Coils
- District Heating Hoses
- Fan Coil Flexible Connectors
- Annealed Flexible Metal Hoses
- Copper Fittings Flexible Metal Hoses