Hose Configuration Requirement  - Hose Assemblies are usually connected at both ends in service.  They may then either remain in a fixed or static configuration or in a flexing or dynamic configuration.

When static or dynamic, the 1st Rule concerning the configuration of the hose is that the bend radius of the hose must never be less than the Minimum Bend Radius (MBR) for the hose as listed in the relevant hose brochure.

The most common situation when this is likely to occur is when the hose is flexed at the end fitting with stress being applied to the hose at an angle to the axis of the end fitting.  Typically this happens either because the length of the hose is too short, or because the weight of the hose plus contents creates a stress at an angle to the end fitting.

2nd Rule, therefore, if possible is to design the configuration to ensure that any flexing in the hose takes place away from the end fittings.

3rd Rule, is that flexed hose configurations which are not suspended vertically downward, but are to one side or upward, shoud be supported to prevent the hose from falling under its own weight, which may kink or otherwise damage the hose.

4th Rule is that the hose configuration should always be designed and supported where necessary, to avoid any possibility of external abrasion.

In some cases, the length, configuration and angle of the hose can be designed to avoid abrasion.  In others, static or moving support frames or support wheels are required.

5th Rule is that the hose must not be subjected to torque, either during connection or as a result of the flexing cycle.

Torque (twist) in the hose can be applied during connection if the hose is accidentally twist, or if the second end being connected is a screwed connection and the hose is subject to torque during final tightening.

In a flexing application, if any flexing cycle of the hose occurs in 3 dimensions instead of 2, then torque will also occur:

Rule 6 is that the hose must not be subjected to any excessive form of external abuse, whether mechanical, thermal, chemical or electrical.  Examples are excessive abrasion, crushing, pulling against a corner, cutting, impacting, contact with weld spatter, contact with a high temperature surfaces or flame, contact with any chemical corrosive to external hose components.  Also, hose assemblies should not be subjected to high voltages, for example when an electric arc weld is struck with a hose assembly in the circuit.

Rule 7 is that the Minimum and Maximum Working Temperatures and Maximum Working Pressures must be determined from the relevant Hose Brochure for the relevant hose and end fitting specifications.  It must be noted in particular that the Maximum Temperature and Maximum Pressures are interdependent, also that they depend not only on the braid but also on any cover material, and types of end fittings.