Technical information

Selections factors Metal Hose:

Size of Connection Pipe.

The size of metal hose for a given application is usually determined by the size of the existing piping and/or fittings.

Temperature of Operation.

Temperature affects the physical properties of all material.

Media in Relation to Corrosion of Hose Material.

A primary consideration in specifying metal hose is to select a material which is resistant to the media to be conveyed through the hose; this is possible in most applications. Remember to consider the corrosive effects of the outside environment, as well as the media covered within. A metal hose is off a thin walled material and will not have the same total length of usage as pipe or tube that is heavy-walled material, even though both are of the same material.

Pressure – Operating, Test and Burst Needed for the Application.

The pressure rating for each type of flexible metal hose is affected by the conditions of actual use, such as, shock or pulsating conditions, temperature, and bending stresses. There is the maximum Working Pressure off the assembly, the Burst Pressure (4 times WP) and the maximum test pressure is 1,5 time the Working Pressure (off the assembly).

Motion Type Affecting Hose and Amount of Motion.

Flexible metal hose is specified for several different applications:

whenever there is excessive vibration
whenever misaligned pipe or tube is encountered
whenever flexibility is needed for manual handling situations.

To select the proper hose for any of these applications requires, careful consideration of the inherent flexibility of the material in regards to the design of the assembly, installation, and versatility expected of the hose.

Length of Hose:

Motion, offset, vibration as well as live length required, are all factors to consider in determining the proper hose selection.

Fittings

End Fittings can consist of flanges, pipe ends, inner- and outer threads but also of all kinds of couplings. There are several attachment methods like welding and soldering. This is partly determined by the type of hose, alloy, pressure, medium and temperature.

Flow Velocity:

High flow velocities in metal hose can cause vibration resulting in noise and premature failure. An Internal liner should be used when the flow velocity of the medium is exeeding the following values:

Hose without braiding : gas 30m/s, liguid 15m/s
Hose with braiding : gas 45m/s, liquid 22,5m/s