The appearance and efficient operation of a system often depend on using pipes of adequate length. The excessive square footage of the tube increases the pressure drops and the cost of the system. Hose assemblies are commonly made for specified lengths and length increments to minimize the size of the inventory that needs to be transported. When calculating the length of the tube, remember that the tube can stretch up to 2% or contract up to 4%. For crimping tool from BOA this is important.
The flexibility of the hose
A hose is designed to flex or bend, not rotate. In fact, if a large diameter high-pressure tube is rotated 7 °, its duration can be considerably reduced, in some cases up to 90%. The high-pressure hose must be routed to flex in one plane. If the plumbing requires that the pipe be routed through a compound curve, the hose must be “broken” into two or more sections so that each one flexes through a single plane. A spring guard prevents the tube from flexing beyond the minimum bend radius of the fitting but does not prevent the tube from bending.
When the hose has to flex, pass it through the pivot point around which the component moves. This will result in the best and most efficient bending of the tube line, use the least amount of hose and keep the tube within the machined contour. To achieve this, the tube must be positioned to bend like a hinge. Otherwise, the tube may have a tendency to take an S-curve, which is more likely to happen when the tube is pushed rather than bent. An S-curve installation results in excessive movement of the pipe and reduced service life. When piping a flexible line through a pivot point, consider the relative positioning of the two fittings to avoid an S-bend by following this procedure: Swing the moving component at the farthest point where the tube will experience its widest bend. If the fittings are positioned in parallel planes at this point, the tube will tend to flex in a hinge way when the component is brought back to the opposite end of its stroke.
In addition to bending, the ends of the hose may have to be reciprocal. There are several design methods for doing this:
Hose Reels: For use with high-pressure hydraulic hoses, these reels are equipped with high-pressure swivel joints and a spring return to facilitate hose rewinding.
Festoon: The tube is hung on loops by a steel cable. When one point of the loop moves away from the other, the loops open to form an almost straight line.
Rolling: The hose is arranged in an unbalanced U-shape with hinged rails that carry the hose. One leg remains stationary and longer than the second, which is free to reciprocate in parallel with the first.
A piping installation is not complete until it has been properly blocked.
Rotary or swivel joints are commonly used to provide rotary movement when the rotary movement is 360° continuous, use a rotary joint. If the movement is in reverse, a swivel joint would be the best choice. When used with a hose, a swivel joint will prevent the hose from kinking or bending over the fitting.