CONVOFLEX' STAINLESS STEEL CORRUGATED FLEXIBLE METAL HOSE (GSS)

Convoflex (SS304 / SS304L / SS316 / SS316L / SS321)


SPECIFICATION : BS 6501



CONSTRUCTION:

Hose & Braid Material :

304 / 304L / 316 / 316L / 321

Tube:

Heavy wall Innercore for corrosive service. Butt welded Annular Corrugations, close-pitch, tubing.

Size Range:

6mm I.D to 600mm

Temperature:

-200ºC. to + 800ºC. for AISI 321 & 316 -200ºC. to + 420ºC. for AISI 304 & 304L


APPLICATION

This hose is suited for any application where working conditions demand one or a combination of any of the following: absolute leakproofness, a high safety factor, extreme temperatures, vibrations, high working pressure and corrosion resistance.

Applicable for cryogenic and chemical transfer, vacuum, super-heated steam, coolant lines, fuel and oil burner lines, petroleum, refrigerants, gases, poisonous media and food stuff.



HOSE SPECIFICATION CHART

CODE I.D inches I.D mm O.D mm Working pressure kgf / cm² Test pressure kgf / cm² Minimum bend radius mm
GSS - 6 1/4 6 14 184 276 90
GSS -10 3/8 10 19 90 135 150
GSS -12 1/2 12 22 80 120 200
GSS -20 3/4 20 29 64 96 203
GSS -25 1 25 36 50 75 229
GSS -32 1¼ 32 35 40 60 267
GSS -38 1½ 38 55 30 45 292
GSS -50 2 50 68 28 42 318
GSS -65 2½ 65 84 24 36 508
GSS -80 3 80 97 18 27 610
GSS -100 4 100 126 16 24 750
GSS -125 5 125 152 12 18 900
GSS -150 6 150 178 10 15 1050
GSS -200 8 200 225 8 12 1180
GSS -250 10 250 278 6 9 1250
GSS -300 12 300 330 5 7.5 1400

For Static pipe work the bend radius can be reduced considerably. For extra high pressure, extra braid can be provided. Consult our Technical Department. For pressure drop estimates, for corrugated metal hose, consult our Technical Department. The above pressure ratings are for fluid & ambient temp. of 30°C.



TEMPERATURE

As the operating temperature of a hose assembly increases, the maximum working pressure of the assembly decreases. Below is a chart showing temperature correction factors for 'CONVOFLEX' Stainless Steel Metal Hose.



TEMPERATURE CORRECTION FACTORS

(ºC) Correction Factor (ºC) Correction Factor
- 200 to 50 1.00 400 0.67
100 0.94 450 0.64
150 0.88 500 0.61
200 0.84 550 0.60
250 0.79 600 0.58
300 0.76 700 0.56
350 0.71 800 0.54


How to use Temperature Corrections Factor Chart?


  • Determine the maximum operating temperature of the application.
  • Locate this temperature on the chart and read across to the proper factor.
  • Multiply this factor times the maximum working pressure as determined from the Hose Specification Chart.
  • This answer is your maximum Safe Working Pressure at that Elevated Temperature.


ADVANTAGES OF FLEXIBLE METALLIC HOSE


  • High physical strength.
  • Suitable for elevated temperature (800ºC).
  • Fire resistant.
  • Good corrosion characteristics.
  • Long life (When installed correctly)
  • Resistance to penetration & damage.


FLEXIBLE HOSES ARE USED FOR THE FOLLOWING MODES OF MOVEMENT


Static Installations

  • Where the Flexible hose is used to connect pipe work out of alignment and remain in static position.

Occasional Flexing

  • When the hose is only required to flex occasionally. Such as manual handling.

Constant Flexing

  • When the hose is required to flex continuously, usually on moving machinery.

Vibration

  • High frequency, low amplitude movement, i .e. on a compressor.


PRESSURE - FOUR EFFECTS


System pressure:

System pressure is the first factor considered in selecting a hose or wall thickness. Where significant pressure fluctuations are not present, a standard hose may be selected by choosing one rated at a pressure equal to or greater than your nominal operating pressure.


Pulsating pressure:

Pulsating pressure is a continuous rippling pressure superimposed on the operating pressure. If the pulsations are significant it is proper to provide margin in selecting the rated pressure for a standard hose.

Surge pressure:

Surge pressures usually occur during system start up, shut down, and rapid valve closure. It is proper to consider the possibility of surge pressures and to provide adequate margin.

Flexibility:

Logically, increasing pressure requires a heavier wall and braid and tightens the braid grip increasing hose stiffness proportionately. As covered in the vibration section however, the tightening of the braid is valuable in controlling vulnerability to vibration by providing necessary damping.



HOSE MOTION -THREE TYPES



Angular motion:

Occurs when one end of the hose is held fixed and the other is deflected in an arc.

Offset Motion:

Occurs when one end of the hose is fixed and the other end is offset but remains parallel to the fixed end. Do not allow this motion to stretch the hose. Use a stress relief loop or equivalent to provide slack.

Axial Motion:

Occurs when one end of the hose is held fixed and the other end of the hose is deflected along the axis of the hose. This type of motion should only be applied to unbraided annular hose or to braided hose where a stress relief loop or offset is provided so that the motion is only locally axial and the hose is not stretched or compressed.