9.3 ACCOMMODATION OF THERMAL EXPANSION

Stainless steel metal hoses are slightly elastic in the longitudinal direction. It is possible to reduce the length by max. 0.6% without compromising the pressure resistance of the hose. Further compression is therefore not allowed.

The following designs are possible to compensate thermal expansion.

9.3.1 Installation plan

Straight or with displacement
Movement: lateral (not for vibrations!)

    installation distance E ≈ NL · 0,994
minimum hose length FL min = 8 · a1
E mm installation distance in axis direction
NL mm total length of the metal hose
FL mm free-moving hose length
r mm smallest bending radius for frequent movements
l mm length of a connection part
a mm total lateral path = 2 · a1
a1 mm lateral path from the middle axis (max.100 mm)

Example 7

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 20 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 101.

Movement data

  • Movement accommodation a = 60 mm

Calculation

a1 a durch 2 = 30 mm

r = 170 mm see hose table

l = 79 mm see dimension table connection parts

NLwurzel aus 20 mal 170 mal 30 + 2 · 79 = 477 mm

FL = 477 - 2 · 79 = 319 mm

E = 477 · 0.994 = 474 mm

i.e. for installation in axis position (middle position) must be shortened by 3 mm

9.3.2 Installation plan

9.3.2 Einbauschema 90°-Bogen Bewegung aus einer Richtung (nicht für Schwingungen!)

90° elbow
Movement from one direction (not for vibrations!)

a durch r Value from bending angle table
The bending angle may not exceed max. 60°.

E1 mm installation distance
E2 mm installation distance
NL mm total length of the metal hose
r mm smallest bending radius
l mm length of a connection part
a mm expansion accommodation
bending angle

Example 8

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 25 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 114.

Movement data

  • Movement accommodation a = 60 mm

Calculation

r = 205 mm see hose table

l = 85 mm

60 durch 205 = 0,293 ist gleich 27° see bending angle table

NL = 0.035 · 205 · 27 + 1,57 · 205 + 2 · 85 = 685.7 mm (Order length NL = 700 mm)

E1 = 205 + 205 (0.035 · 27 - 2 · sin 27°) + 85 = 297.6 mm

E2 = 205 + 2 · 205 · sin 27° + 85 = 476.1 mm

9.3.3 Installation plan

9.3.3 Einbauschema 90°-Bogen Bewegung aus zwei Richtungen (nicht für Schwingungen!)

90° elbow
Movement from two directions (not for vibrations!)

E1 mm installation distance
E2 mm installation distance
NL mm total length of the metal hose
r mm smallest bending radius
l mm length of a connection part
a1 mm expansion accommodation axial
a2 mm expansion accommodation lateral
bending angle = +
β bending angle = +

Example 9

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 32 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 101.

Movement data:

  • axial a1 = 66 mm
  • lateral a2 = 25 mm

Calculation

r = 260 mm see hose table

l = 96 mm see dimension table connection parts

 = 66 durch 260 = 0.253 ist gleich 28° see bending angle table

β25 durch 260 = 0.0916 ist gleich 18° see bending angle table

NL = 0.035 · 260 · 28 + 0.035 · 260 · 18 + 1.57 · 260 + 2 · 96 = 1,018.8 mm

E1 = 260 + 2 · 260 · sin 18° + 260 (0.035 · 28 - 2 · sin 28°) + 96 = 527.4 mm

E2 = 260 + 2 · 260 · sin 28° + 260 (0.035 · 18 - 2 · sin 18°) + 96 = 603.2 mm

9.3.4 Installation plan

9.3.4 Einbauschema 90°-Bogen Bewegung aus zwei Richtungen (nicht für Schwingungen!)

90° elbow
Movement from two directions (not for vibrations!)

E1 mm installation distance
E2 mm installation distance
NL mm total length of the metal hose
r mm smallest bending radius
l mm ength of a connection part
a1 mm expansion accommodation horizontal
a2 mm expansion accommodation vertical
bending angle = +
β bending angle = +

Example 10

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 40 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 114

Movement data

  • Expansion accommodation a1 = 78 mm horizontal
  • Expansion accommodation a2 = 23 mm vertical

Calculation

r = 310 mm see hose table

l = 95 mm

78 durch 310 = 0.252 ist gleich 28° see bending angle table

β23 durch 310 = 0.0742 ist gleich 16° see bending angle table

NL = 0.035 · 310 · 28 + 0.035 · 310 · 16 + 1.57 · 310 + 2 · 95 = 1,154.1 mm

E1 = 310 + 2 · 310 · sin 16° + 310 (0.035 · 28 - 2 · sin 28°) + 95 = 588.6 mm

E2 = 310 + 2 · 310 · sin 28° + 310 (0.035 · 16 - 2 · sin 16°) + 95 = 698.9 mm

9.3.5 Installation plan

9.3.5 Einbauschema 180°-Bogen Bewegung aus einer Richtung

180° elbow
Movement from one direction

E mm installation distance
NL mm total length of the metal hose
r mm smallest bending radius
l mm length of a connection part
a mm lift
h1 mm max. height of the 180° elbow
h2 mm min. height of the 180° elbow

Example 11

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 40 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 114.

Movement data

  • Lift a = 150 mm

Calculation

r  = 205 mm mm see hose table

l = 85 mm

NL = 205 · w + 1.57 · 150 + 2 · 85 = 1,049.2 mm (Order length NL = 1,100 mm)

h1 = 205 + 0.785 · 150 + 85 = 407.8 mm

h2 = 205 + 150 durch 2 + 85 = 365 mm

9.3.6 Installation plan

9.3.6 Einbauschema 180°-Bogen Bewegung aus zwei Richtungen

180° elbow
Movement from one direction

E mm installation distance
NL mm total length of the metal hose
r mm smallest bending radius
l mm length of a connection part
a1 mm total travel horizontal
a2 mm total travel vertical
h1 mm max. height of the 180° elbow
h2 mm min. height of the 180° elbow

Example 12

Beispielberechnung

Example

Rattay stainless steel corrugated hose DN 40 Type HR I/S, on both sides screw connections made of stainless steel, Fig. 114.

Movement data

  • Hub a1 = 210 mm horizontal
  • Hub a2 = 175 mm vertical

Calculation

l = 89 mm

r = 310 mm see hose table

NL = 310 · w + 1.57 · 210 + 175 durch 2 2 · 89 = 1,568.6 mm (Order length NL = 1,600 mm)

h1 = 310 + 0.785 · 210 + 175 durch 2 + 89 = 651.4 mm

h2 = 310 + 210 minus 175 durch 2 + 89 = 416.5 mm