What is the difference between tube & pipe?

Question

for eg :

we call boiler tubes & kerosene line or pipe.... am confused about this???? :-(

Answer 1

The tube is bigger than the pipe

Answer 2

They're all pipes.  There are two types.  Barrel starts life as a rod and has a hole bored through it.  Tube starts as a flat sheet which is bent round and welded together.  Tube is also used to describe flexible pipes made by extrusion.  Barrel has more or less died out, except for wooden pipes in musical instruments.  (The stuff you can buy as black iron barrel is actually mild steel tube).  So when it comes to plumbing, there's no difference.

Answer 3

You wouldn't go from Victoria to Oxford Circus in a pipe and you wouldn't smoke a tube!

Answer 4

*It is common to identify pipes in inches by using NPS or "Nominal Pipe Size". The metric equivalent is called DN or "diametre nominel". The metric designations conform to International Standards Organization (ISO) usage and apply to all plumbing, natural gas, heating oil, and miscellaneous piping used in buildings. The use of NPS does not conform to American Standard pipe designations where the term NPS means "National Pipe Thread Straight".

Nominal Bore (NB) may be specified under British standards classifications along with schedule (wall thickness).

*The tolerances are looser to pipes compared with tubes and they are often less expensive to produce.

*The nominal dimensions of tubes are based on the outside diameter. If we look at Copper Tubes - ASTM B88 the outside diameter of a 2" pipe is 2.125", relatively close to 2".

The inside diameter of a tube will depend on the thickness of the tube. The thickness is often specified as a gauge. If we look at Copper Tubes - ASTM B88 the wall thickness of 0.083"of a 2" pipe is gauge 14.

*The tolerances are higher with tubes compared to pipes. Tubes are often more expensive to produce than pipes.

*The distinction between tube and pipe, based on wall thickness limit and/or wall to diameter ratio), is a little different from industry to industry. Tubing is considered as having a wall thickness of up to 1/4-in. or less and a diameter of 6-in or less, while pipe has a wall thickness above 1/4-in. and a diameter greater than 6-in. Having said this, the author has done development work for a stainless steel structural tubing producer at wall thicknesses up to 0.315-in., hence the rather blurred nature of the definition.

-(If the wall thickness is expressed in ga(u)ge no. it's tube, whereas if it is in schedule no. or class then it's pipe.

If the dia. is 6mm (1/4'') or less it's tube, whereas if it is more than 6mm it's pipe.

Tube is available in coil form, not pipes due to the simple fact that pipe wall thickness does not permit coiling.)