CADWorxP&ID tab: Instruments > Combine Instruments 
Instruments toolbar: Combine Instruments
Misc toolbar: Combine Instruments
P&ID menu: Accessory > Database > Combine Instruments
Command line: COMBINEINST
Combines instrument bubbles into a group. This is typically used to combine all instruments
within one loop. You can then use Edit 
to modify the value of Tag simultaneously for all combined instruments. For more information, see Edit and Editing Instrument Component Dialog Box.