No. Air pockets may form if concentric reducer is used at pump suction, which results in cavitation and cause damage to Pump. To avoid this problem, Eccentric Reducer with flat side up (FSU) is used in Pump Suction.
Piping where the most uniform application of heat/temperature is required to the process, where steam tracing is not capable of maintaining the temperature of fluid constantly.Usually used for molten sulphur, Polymers service etc.
The thumb rule is that the minimum distance between adjacent butt welds is 1D. If not, it is never closer than 1-1/2 inch. This is supposedly to prevent the overlap of HAZs. Minimum spacing of circumferential welds between centerlines shall not be less than 4 times the pipe wall thickness or 25 mm whichever is greater.
For this reason many company standards advice the minimum spool length of pipe which is usally 100mm in genral but may differ.But in cases where required the minimum distance for adjacent welds can be considered
Weldolet and Sockolet are basically self-reinforced fittings.Weldolet is used for Butt weld branch connection where standard tee is not available due to size restrictions and the piping is of critical / high-pressure service. Sockolet is used for socket welding branch connection, which require reinforcing pad.