There are two types of stainless steel flexible pipe manufactured in Europe and Asia

  • The most common is called Corrugated where the stainless steel rolls of sheet are formed into a plain tube, then through another machine rings are formed often very close to be very flexible for the gas hose industry, but for sanitation and solar the pitch between each ring is greater, so less flexibility, but still very bendable unlike copper pipe
  • Corrugated pipe can be easily cut by a copper pipe cutter and with a simple tool, a end flange can be formed after the union nut has been placed over the end
  • The second type of flexible pipe is called Helical, which is where the same type of pipe is made, then passed through a machine that creates a spiral affect, allowing fittings to be screwed over the tube. For this type of pipe, no flange tool is required, instead a diamond disc cutter is needed to cut the pipe before a patented brass coupling can be fitted
  • The benefit of the Helical pipe in comparison to the Corrugated is the water flow touches all parts of the inside wall of the Helical pipe as it passes through the pipe, compared to the Corrugated because of the rings


The importance of understanding the different variations of corrugated pipe manufactured by the major producers of the
solar hose type pipes

  • The 3 main grades of stainless steel used in the processing of the corrugated pipe are AIS304,
    316 and 316L
  • Depending which country the pipe is being imported into, the 304 due to lower price would be
    purchased with the thermo siphon type systems sold in hot climates and the developing world,
    while the 316 and 316L is generally used into central Europe and the USA due to higher water quality
  • The vast majority of this type of pipe assembled by the majority of companies in Europe is 316-
    316L corrosion resistant
  • The standard pipe Internal Diameter (ID) sizes are shown as DN 10mm, 12mm, 16mm, 20mm and 25mm
  • The standard pipe Outside Diameter (OD) sizes are DN 14.10mm, 16.5mm, 21.5mm, 26.5mm and 32mm
    with variations of +0.2-0.5 depending on the manufactures machine configuration
  • The next area to be sure of is the thickness of the stainless steel sheet, which in most cases for
    use in solar and sanitation installations is from 0.25mm- 0.30mm
  • At a temperature of 300c, the ½” & ¾” (16mm & 22mm) can withstand a pressure of 13 bar
  • The final part of deciding who to purchase solar hose from, first you need to know the space
    between the bellows (rings) called the pitch and obtain samples to check the Tig weld seam
  • Once the right type of pipe has been selected for your solar or sanitation requirement, the next
    most important part of the purchase is in the type and method of making the end flanges on the
    cut ends of the pipe (Corrugated)
  • Then select the type of material used in the making of the brass union and varied nipples used
    to join the solar hose to copper or male/female brass compression brass fittings

The developer of solar Speedflex has already experienced all these issues which allows you the buyer to buy from us with confidence.