The volume of the metal? Or, the volume contained within the fitting? I don't recall seeing either for fittings, only pipe.
If it's the volume of the metal, weigh a few, get the average and use the metal density to find the metal volume.
If it's the volume contained within the fitting, that can be measured quite easily too with water. Just be sure and subtract out the volume displaced by inserting the pipe into the BW fittings.
If the fittings are too big for weighing or measuring to be practical, estimate by taking dimensional measurements.
You ask fittings in general but I think your question only apply for elbows. All others are straight pipe somehow connected to each other and are as such not necessary to know separatelyYou ask fittings in general but I think your question only applies for elbows. All other fittings are straight pipe somehow connected to each other and are calculated as straight pipe in the system.
The content of an elbow is depending on the radius (SR, LR, 3D, 5D, etc) not so difficult to calculate. I have never seen a table for this, but it is easy tho compile in e.g. Excel or Quattro Pro.
You can try to contact a pipe supplier in your country, see what he says.
I know for pipe and I can calculate for an elbow according to his radi but i wanted a quick easy way to determine the volume the more exactly possible when using standard BW fitting.
The volume is different than straight pipe on elbows, caps and reducing fittings and I may verify with B16.9 if there is any standard dimensions on cap end thickness and transition dimensions and geometry for reducing fitting instead of only overall length dimensions.
This is not as simple as it seems. If you are looking for accurate numbers you need to realize that ASME B16.9 requires that the thickness be not less than 12.5% less than nominal, and that the fitting must have a pressure rating equivalent to straight seamless pipe. The maximum wall thickness is not really specified. Technically (and somebody correct me if I am wrong) a manufacturer could produce all schedule 160 fittings, taper bore the ends to schedule 40, and mark/sell them as schedule 40 fittings. The internal profiles of fittings could vary widely amongst differnt manufacturers. For example, picture a tee manufactered by machinging a forged block, and then picture a tee manufactured by forming an extruded outlet. Both fittings could comply with B16.9, but the metal volumes, and the internal volumes could differ significantly.
Certified drawings from manufacturers might help. Otherwise, I like Latexman's suggestions for determining either the internal or metal volumes.
