Full bore 22mm flexible hoses

In article , Capitol writes

BES have 22mm with 19mm bore in 30cm length, code 13753, but only

However, I don't think a *short* length of reduced bore makes a lot of difference, a 30cm length of 13mm will have the same restriction as 70cm of 22mm; if I calculate correctly. 60cm of 13mm == 1.4m of 22mm.

The hydraulic resistance of a tube is inversely proportional to the FOURTH power of its radius. [1]

The bore of 22mm pipe is about 19mm So the 30cm of 13mm bore is the same as (19/13)^ x 30cm That's about 136cm of pipe. Not a big problem.

HTH

For viscous fluids and lowish speeds then pressure loss is only proportional to the speed. Hence resistance only(!) inversely proportional to the cube of the bore size.

Thanks for the correction Ed, real life should have told me that was the case ;-)

Thanks Capitol

Did JG Speed fit existed around the time of the original OP's post?

We started using the smaller sizes from the mid seventies where they replaced Enots brass compression fittings for a lot of applications. The first week we had them the store man got a bit sniffy as following the general style of the Cadburys Smash Martian which was on the TV at the time we used a hundred or so fittings to build something similar with a pressure gauge for a face and put it on his desk. Being a typical miserable bastard store man he complained about the cost "You've just wasted about £50 pounds of fittings "as he was oblivious that they could be easily separated without damage.

G.Harman