General information

Metal hoses are flexible corrugated „pipes“ manufactured by forming of thin metal sheets from stainless steel. For increase of pressure resistance and mechanical protection are metal hose braided by wire from stainless steel. To hoses are welded threaded, flanged, and welded fittings, or special fittings defined by drawing or standard.

Lengths of hoses and combination of fittings are always individual, according requirements of customer.
  • Metal hoses are manufactured in dimensions from DN5 up to DN 500
  • Thermal resistance of metal hoses is from -196°C up to 600°C
Metal hoses are in standard execution from stainless steel resistant in range of temperature -190°C up to 600°C. In case of higher working temperatures in thermal range 100°C up to 600°C is nominal pressure PN mentioned in tables of individual types of hoses reduced by particular coeficient kt, which takes into account working temperature of transported medium or outside temperature and type of hose material. Allowed working pressure pallow=PN x kt.

Pressure coeficient kt


 

Material of hose
Temperature (°C)

AISI 321

AISI 316 L

20

1

1

100

0,83

0,83

150

0,75

0,76

200

0,69

0,69

250

0,65

0,65

300

0,62

0,61

350

0,59

0,58

400

0,58

0,56

450

0,57

0,54

500

0,56

0,53

550

0,53

0,52

600

0,34

0,44

Pressure resistance of hose depends on dimension of hose, type of braiding and working temperature of medium.

Use of hoses

Metal pressure hoses are used for flexible guidance of liquids and gases on technological equipments, where is required resistance against high temperature of medium and outside environment, resistance against chemically aggressive medium and chemical aggressivity of environment and also on equipments where is required high level of safety, reliability and life-time of processes.

Material of hose

In standard version are metal hoses manufactured from stainless steel AISI321 and AISI 316L.

Material of braiding

For increasing of pressure resistance and mechanical protection are metal hoses braided with wire from stainless steel AISI304 (ISO 10), chemical composition corresponds with standard STN steel quality 17 240.

Bending radius

Bending radius mentioned in tables are indicated from middle of bending up to middle of hose (axis). Standard ISO distinguishes static and dynamic bending radius. Static radius defines sigle bend, for example at placement (assembly) of hose. Dynamic bend is related to repeated bend.

Manufacturing tests

Company KOHAFLEX provides:
  • 100% pneumatic test for air leak pressure or nitrogen up to pressure 0,6 MPa
  • Hydraulic test by pressure resistance 1,5-time of nominal pressure
  • Helium leak test (necessary to order)