PVC Pipe L/D Ratio

Length to diameter ratio.

After having seen your other question, please do some independent research before coming here.

If you are going to start a factory, hire a process engineer.

Otherwise, Google or Wikipedia can answer these type of questions nicely.

Length to diameter? What do you mean by pvc machine?

He may be talking about the L/D ratio of the extruder screw itself.

That's kinda important, depending on the material one is extruding. Don't think it has anything to do with the pipe that the machine makes.

That's why I asked for clarification on what machine he is talking about.

He's talking about pvc pipe, pvc machine no mention of exactly what the machine function is. An extrusion machine would not necessary be called a pvc machine exclusively. Could be used to extrude other plastics.

Yes,

But L/D ratios can be "general purpose" or material specific. (If you already know all this tell me and I'll quit lecturing you.)

Duh what you talking about.

As mentioned previously, it is the relationship between the diameter of the screw and the length of the barrel that the screw is effective in. Example - PVC extrusion - effective machines are generally in the 24:1 or 30:1 or 36:1 lengths versus screw diameter. As to what is "best" - would depend on what you intend to do with the machine - pipe machines tend to be run at high rates with highly filled materials although we have achieved 475+ pounds per hour on 3 1/2" single screw machines at 24:1.

Just our two cents

Jim Wilson

http://www.skippyandbuzz.blogspot.com/

The term also crops up in pipeline pressure drop analysis, particularly the Darcy-Weisbach equation (ask Wikipedia about fluid dynamics).