Hose Assembly – Installation Guide

» Technical » Hose Assembly Guides » Hose Assembly – Installation Guide

Hose Assembly

Proper hose installation is essential for satisfactory performance. If hose length is excessive, the appearance of the installation will be unsatisfactory and unnecessary cost of equipment will be involved. If hose assemblies are too short to permit adequate flexing and changes in length due to expansion or contraction, hose service life will be reduced.

The following diagrams show proper hose installations which provide maximum performance and cost savings. Consider these examples in determining length of a specific assembly.

hose assembly straight hose installation
When hose installation is straight, allow enough slack in hose line to provide for length changes that will occur when pressure is applied.
hose assembly flexing applications
Adequate hose length is necessary to distribute movement on flexing applications, and to avoid abrasion.
hose assembly twist bend 1
When radius is below the required minimum, use an angle adaptor to avoid sharp bends.
hose assembly twist bend 2
Avoid twisting of hose lines bent in two planes by clamping hose at change of plane.
hose assembly twist bend 3
Use proper angle adaptors to avoid sharp twists or bends in the hose.
hose assembly twist bend 4
Prevent twisting and distortion by bending hose in same plane as the motion of the boss to which hose is connected.
hose assembly reduced number of pipe fitting
Reduce number of pipe thread joints by using proper hydraulic adaptors instead of pipe fittings.
hose assembly use 45deg 90deg adaptors
Route hose directly by using 45° and/or 90° adaptors and fittings. Avoid excessive hose length to improve appearance.
hose assembly allowing length change
To allow for length changes when hose is pressurised, do not clamp at bends. Curves will absorb changes. Do not clamp high and low pressure lines together.
hose assembly avoid twisting hose
When installing hose, make sure it is not twisted. Pressure applied to a twisted hose can result in hose failure or loosening of connections.
hose assembly high temperature
High ambient temperatures shorten hose, therefore ensure hose is kept away from hot parts. If this is not possible, insulate hose.
hose assembly relieve strain
Elbows and adaptors should be used to relieve strain on the assembly, and to provide neater installations which will be more accessible for inspection and maintenance.
hose assembly avoid collapse and restriction
To avoid hose collapse and flow restriction, keep hose bend radii as large as possible. Refer to hose specification tablesfor minimum bend radii.
hose assembly avoid abrasion
Run hose in the installation so that it avoids rubbing and abrasion. Often, clamps are required to support long hose runs or to keep hose away from moving parts. Use clamps of the correct size. A clamp too large allows hose to move inside the clamp and causes abrasion.

When determining the length of hose assemblies, provide sufficient length to prevent bending strain from localising at the back of the coupling. In the diagram below, measurement “B” allows for a strain section of hose beyond the coupling to prevent concentration of bending strain. “T” designates the amount of travel. “A” indicates the smallest diameter to which hose should be bent.

Overall length = B+1.57A+T

Typical Dimension For One & Two Wire Braid Hose

DN inch Dash
6 1/4 -04 250 mm (10″)
10 3/8 -06 250  mm (10″)
12 1/2 -08 300  mm (12″)
19 3/4 -12 350  mm (14″)
25 1 -16 400  mm (16″)
31 1.1/4 -20 450  mm (28″)
38 1.1/2 -24 500  mm (20″)
51 2 -32 500  mm (20″)
hose assembly determining the length