Pressure
dependencies from temperature
PE = Maximum operating pressure in ambiental temperature (bar)
P = Operating pressure (bar).
T = Operating temperature (°C).
Kt = Pressure conversion constant in function of temperature.
P >= PE x Kt Temp. T °C Kt Pressure conversion constant in function of temperature
Curvature
radius
Dynamic curvature radius "Rn", sown in the tables, is valid for 50.000 movements and "PE" pressure. Static curvature radius "R Min", shown in the tables, is valid for only one movement at "PE" pressure.
Test
pressure
Test pressure do not exceed 105 times maximum pressure "PE".
Blowout
pressure
Blowout pressure is 4 times maximum pressure "PE"
Fluid
speed
To avoid resonance problems, which can cause premature breakages, piped fluid speed do not exceed 40 m/sec.
For
right installations
Do not exceed maximum curvature radius.
This is very important for curvature near joints. Here infact inflecting moment is maximum.Besides is importan to remember that al least only one exceeding of curvature radius somewhere can damage the pipe.
Don not twist the pipes.
Never twist flexible pipes.
Undulating flexible pipes have very high polar inertial moment respect to inflecting inertial moment, so are inclined to trasform a twist into a inflection, mostly exceeding the limits for curvature radius.
Speed
limit for fluid
Avoid high speed for fluids in flexible pipes, they can cause resonance problems which reduce the life of pipes.
Dry gas in rectilinear flexible pipes:
- without metallic braid 30 m/s
- with metallic braid 45 m/s
Introduce this constant of speed reduction if bends are present:
- 180° bend: 0.25
- 90° bend: 0.50
- 45° bend: 0.75
- fluid in flexible hose with or without metallic braid: about 5 m/s
- damp water steam in flexible pipes with or without braid: circa 10 m/s
U
installation for vertical movements
U
installation for horizontal movements
C
installation for horizontal installation
C
installation for vertical movements