Installation Method - PREVOST PPS1 CI16 Documentación Técnica

GB
EXPANSION - CONTRACTION
All materials change size as temperatures vary. Generally, plastics expand
and contract more than metal.
When compared with a reference temperature (installation temperature):
- they expand as temperatures rise,
- and contract as temperatures drop.
The extent of these variations is given by the coefficient of linear expansion d.
For System with aluminium pipes PPS, this efficient d is 0.024
mm/m/°C or, 0.024 millimetres per metre per degree Celsius.
The chart below shows the various coefficients of linear expansion for a
number of widely used materials:
Steel
Copper
PPS
ABS
PVDF
PP
PE
This phenomenon should be taken into consideration when designing and
building any kind of system. It is obtained by the following formula:
ΔL = d x L x ΔT
Where:
d
= coefficient of expansion
L
= length of pipe
ΔT
= temperature difference in degrees Celsius
DL
= difference in length (expansion or contraction)
Example: installation temperature +10°C; length of pipe 20 m; service
temperature 35°C
ΔT = 35 – 10 = 25° C
DL = 0,024 x 20 x 25 = 12 mm

INSTALLATION METHOD

12,8 x 10 m / m / °C
-6
16,5 x 10 m / m / °C
-6
24 x 10 m / m / °C
-6
101 x 10 m / m / °C
-6
120 x 10 m / m / °C
-6
150 x 10 m / m / °C
-6
200 x 10 m / m / °C
-6
Among the most effective methods for compensating for expansion and contractions,
we suggest installing a " flexible hose " or " changing the direction " of the pipes.
The main consequences of expansion and contraction are:
Expansion
Bending of pipes between two fixed points.
Compression of structures, clamps or devices forming fixed
points that could cause pipes to bend, sag or burst.
Contraction
Tension in pipes between two fixed points.
Compression of structures, clamps or devices forming fixed
points that could cause pipes to bend or burst
To prevent the effects of expansion and contraction from significantly
damaging the system and its appearance, follow the directions below to
allow the pipes to flex and compensate for expansion and contraction:
- Support and strengthen the system such that pipework can flex
freely between two fixed points.
- Add a special fitting between fixed points that are spaced far
enough apart to cause significant contraction or expansion.
10