Piping systems in industry often suffer from pressure, temperature variations, vibration and movement so flexible metal hoses can be a key part of the installation. These flexible metal hoses provide a connection between the equipment and pipework, whilst enabling controlled movement.
Depending on the type of metal hose required to suit your application, there will be different considerations to take into account. Factors such as the type of fluid, pressure, temperature, movement and installation will determine what style of flexible metal hose is best suited to your application. Choosing the right metal flexible hose manufacturer will ensure you receive a product that will meet your requirements.
At Essem Works Pvt. Ltd. we manufacture Stainless Steel Braided Corrugated hoses, Interlock hoses & Metal Bellows Expansion Joints. We understand what application and technical requirements are needed to specify the right product for your requirements.
What is a Metal Flexible Hose?
A metal flexible hose is a flexible connection made from metal (typically stainless steel). Depending on the style of metal hose it can be used for transferring fluids/gases, vibration dampening, thermal movement or mechanical protection.
There are many different styles of metal flexible hose available. The two most common types are Corrugated Metal Hoses and Interlock Metal Hoses. Whilst these types of hoses may look similar they have different constructions.
- Corrugated Metal Hose – This hose is constructed from a continuous corrugated tube. It can be designed to resist pressure with the addition of a wire braid.
- Interlock Metal Hose – This hose is created by mechanically interlocking a shaped metal strip. It is typically used for mechanical protection, high temperature applications and abrassive applications.
Types of Metal Flexible Hoses
Depending on the requirements of your application there are different styles of metal flexible hose:
1. Corrugated Metal Flexible Hose
This hose is formed from a flexible metal tube with corrugations. Adding a wire braid to the hose helps to restrict pressure expansion. Braided Corrugated Metal Hoses are commonly used for pressurised fluids and gases.
At Essem Works we manufacture Stainless Steel Braided Corrugated hose assemblies in sizes from DN6 up to DN350. We offer these in 304L, 316L & 321.
2. Interlock Metal Flexible Hose
Interlock hoses are formed by winding and interlocking shaped metal strips. These hoses are not designed to be pressure tight like pressure corrugated hoses.
These are commonly used in applications where heat resistance, abrassive and mechanical protection is required. They can also be used as protective covers/liners.
We manufacture Stainless Steel Interlock hoses in sizes from DN6 up to DN200. We offer these in SS 304 as standard and SS 316 & 321 can be ordered.
3. Braided Metal Flexible Hose
Braided Metal Hoses are formed from a corrugated metal inner tube and one or more layers of stainless steel wire braids. The braided outer layer helps to control pressure expansion whilst still maintaining flexibility.
Depending on your application you may want to use a single or double braid. This will depend on the working pressure, temperature, diameter of hose and movement.
4. Metal Bellows & Expansion Joints
Metal Bellows Expansion Joints are designed to absorb specific movements within your piping systems. They can absorb axial, lateral & angular movements.
They are commonly used in applications where there is thermal expansion/contraction or equipment movement. They need to be designed to take into account movement, pressure thrust, spring rate & fatigue.
How Do Metal Flexible Hoses Work?
Depending on the type of hose:
- Corrugated Metal Hose – The corrugations within the hose provide flexibility. If it is Braided then the external reinforcement will help control expansion.
- Interlock Hose – The interlocked metal strips provide mechanical flexibility. They are not pressure tight replacements for corrugated hoses and can provide heat & abrassive protection.
- Metal Bellows Expansion Joint – Special formed convolutions are used to absorb specific movements.
Choosing the correct construction will depend on what you require the hose to do.
Applications Using Metal Flexible Hoses
Metal flexible hoses are commonly used within several industries.
- Chemical & Petrochemical – Compatible chemical transfer lines, process connections & equipment vibration dampening.
- Oil & Gas – Selected process connections, pump connections, loading and gas applications.
- Power Generation – Steam related connections, thermal movement & equipment connections. Assemblies will need to be specified correctly.
- Pharmaceutical Manufacture – Suitable process & utilities connections. With specific material & surface finishes.
- Food & Beverage – Compatible transfer applications.
- Cement & Steel – Selected high temperature, vibration & mechanical protection applications.
- HVAC & Mechanical – Equipment connections with vibration dampening.
The construction, material & connection type will need to be compatible with the process medium.
How to choose the right metal flexible hose
There are more considerations to take into account than just the required diameter of hose. If you are looking to compare suppliers or find a metal flexible hose manufacturer; then these are some important points to consider.
1. Application & Medium
What is going to be passed through the hose? The properties of the medium will determine what material & construction your hose will need. These properties include the chemical make-up, viscosity & potential corrosive nature.
Will you require a pressure tight hose for transferring fluids or mechanical protection?
2. Material Grade
Common stainless steel grades used within metal hose assemblies are:
SS 304L – Suitable for many general industry applications.
SS 316L – Considered for applications that may require increased resistance to certain corrosive environments.
SS 321 – Used in selected applications that benefit from its high temperature properties.
Choose the correct material based on the actual operating conditions.
3. Pressure
What is the normal working pressure, max pressure & pressure surges within the system? The hose assembly needs to be chosen based on its rated pressure at the working temperature.
The diameter, corrugation, braiding & end fittings will affect the pressure capability.
4. Temperature
The material properties & working pressure of a hose assembly will be affected by the temperature. Consider the minimum & maximum operating temperatures. Also consider any temperature fluctuations during start-up/shutdown.
5. Movement & Bend Radius
Will there be any axial, lateral & angular movement, vibration or constant flexing? Each hose type will have different movement limitations & minimum bend radii.
Try not to twist, stretch or bend the hose outside of the recommended levels to prevent premature failure.
6. Hose Size & Length
The hose diameter needs to be correct to allow the required flow without causing excessive pressure loss & vibration due to the flow. The length needs to be appropriate for the installation & movement. Also ensuring it doesn’t exceed the recommended bend radius.
7. End Fittings
Ensure the end fittings are compatible with the equipment & pipework. Depending on the application you may require threaded, flange, weld, hygienic & quick release connections.
8. Testing & Certification
Ask your supplier what standards, inspections & testing will be carried out. For pressurised assemblies hydrostatic testing will be carried out & you will receive a test certificate.
Why Choose Us?
At Essem Works Pvt. Ltd. we manufacture Stainless Steel Flexible Hose Assemblies & Metal Bellows Expansion Joints. We offer Corrugated Braided hoses, Interlock hoses & various Expansion Joints.
We understand that the performance of a flexible metal hose will depend on the construction of the hose. We focus on the technical specifications & requirements of the application rather than taking a standard catalogue approach.
We offer:
- Several different configurations – Corrugated, Interlock & Metal Bellows.
- Stainless Steel Materials – We work with 304L, 316L & 321.
- Range of Sizes – Corrugated hoses from DN6 to DN350. Interlock hoses from DN6 to DN200.
- Custom Assemblies – We manufacture assemblies to your drawings & end fittings.
- Manufactured In House – Corrugating, braiding, welding & testing is all completed in house.
- Certifications – We have ISO 9001:2015, ISO 14001:2015 & ISO 45001:2018 certifications from TÜV Rheinland.
All pressure assemblies are tested using hydrostatic testing at 1.5x working pressure. A test certificate will be provided with your assembly.
We encourage our customers to provide details of the medium, pressure, temperature, movement & end fittings so we can understand your application better & create an assembly to suit your application.
Conclusion
Metal flexible hoses can be an important part of your piping systems within industry. However you will need to have a clear understanding of what pressure, temperature, medium & movement requirements you have within your application to choose between Corrugated, Interlock & Metal Bellows.
Choose a metal flexible hose manufacturer who understand the technical aspects, offer suitable materials, manufacturing & testing.
At Essem Works Pvt. Ltd. we manufacture Stainless Steel Flexible Hose Assemblies & Metal Bellows Expansion Joints. We focus on the requirements of the application. Please get in touch with your specifications or technical drawing & our team can help you find a suitable solution.
FAQ
1. What grades of stainless steel are used?
Common grades are SS 304L, SS 316L & SS 321. The grade will depend on the process medium, temperature & corrosion.
2. What is the purpose of braiding?
Wire braiding provides reinforcement to the corrugated metal hose. It helps to restrict pressure expansion. You may choose single or double braid depending on the pressure & application.
3. Are they available as custom assemblies?
Yes. Metal hose assemblies can be specified in different lengths, diameters, braiding & end fittings. Custom assemblies should be designed to suit the application & approved technical drawing.
4. Do you manufacture metal flexible hoses?
Yes. We manufacture Stainless Steel Braided Corrugated hoses, Interlock hoses & Metal Bellows Expansion Joints. We offer different material options, sizes & end fittings.