Hydraflex Metal Hose & Bellows, Hydraflex Plumbing & Cooling

Understanding Elbow Rotation, for Plumbing and Industrial Hose Orientation

How to correctly identify the elbow rotation for plumbing and industrial assemblies and identify the angle of rotation.

  • The importance of identifying the correct elbow orientation
  • How to work out angle rotation for hoses with elbows at each end
  • Correct and incorrect use of an elbow on a plumbing or cooling hose

Why use an Elbow Fitting?

Whether it is an EPDM plumbing hose or an OEM hose there is significant importance in understanding the implications of incorrect elbow orientation from specification to installation. Elbow fittings, also known as a bend, angle or 90° fitting are used when a bend radius of a hose would need to be exceeded and therefore offer a resolution to surpassing this limit, most commonly as either a flat face or cone seat female in plumbing and cooling applications. The set direction is dictated to by the fixed connections that the flexible is being connected to during installation.

Diagram 1 - Elbow Rotation Angle

Angle of Elbow Rotation with Two Elbows

Orientation of an elbow is described in degrees of a circle as shown in Diagram 1. For assemblies fitted with two elbows, the correct way to describe the angle differential is by starting at the elbow which is furthest away. This elbow should be held at the 12 o’clock position (vertical) with the measurement taken from the closest fitting at a clockwise rotation. The standard rule is to allow the hose to curve down from the furthest elbow. Once the orientation has been confirmed this will be displayed in drawings and will be included in the Hydraflex description.

Elbow Rotation with One Elbow

Elbow rotation can also be needed for fittings that only have one elbow; this is predominantly required for OEM customers. In this instance the angle of the elbow needs to be in relation to the natural bend of the hose. The hose should be held with the straight fitting furthest away and the natural hose curve allowed to hang vertically downwards. The position of the elbow should be measured as per the degrees in Diagram 1.

Why is the Elbow Rotation Important?

This angle is vitally important for longevity of the assembly and holds potential implications in installation and over time with incorrect positioning. Over a period of time or when under pressure can create undue stress on the ferrule causing the fitting to become detached from the hose at the swage causing a failure in the system, leading to unnecessary costs. This is shown in the last line of Table 1, highlighting the importance of avoiding twisting and stretching. A 10° tolerance is standard for our assemblies with elbow orientation, although this is rarely required as there can be minimal displacement during the swaging process.

Table 1 - Correct and Incorrect use of an Elbow

The below table shows best practice to take into consideration when deciding upon end fittings and when an elbow is required. If an unknown degree is required then an elbow adaptor may be more suited for simpler installation, but the below information should still be followed where appropriate.

Correct

Incorrect

Use elbow fittings where minimum bend radius is exceeded to avoid unnecessary strain on the flexible.

Ensure a smooth curve is possible and the minimum bend radius is adhered to on the flexible.

Avoid bending the hose at the ferrule, use an elbow to ensure undue strain is not applied.

Ensure that there is not excessive bend in the assembly and observe the minimum bend radius.

Avoidance of Twist and Stretch. If an assembly is twisted it will substantially shorten its life span, avoid this to reduce strain on the flexible

Need More Information?

If you need anything further on this topic or any other technical information, then please contact one of our technical team to discuss your required specification and the correct orientation to ensure the lifespan of the flexible is not impacted.

Contact James Beacon, Operations Manager at Hydraflex Plumbing and Cooling Hoses Division for further information.