As my good friend Roman explained, steam is a very good option, but an even more efficient method is to inject a chemical with the steam (vapor phase cleaning). This not only quicker, but breaks up any of the residual pitch that may be left in the heater. This is a good idea when preparing for ANY pigging project. Pitch / tar is the real ‘killer’ of a successful pigging operation.
Pigging technology today is such that u-bends and plug headers ‘normally’ do not pose a problem as Chakra mentioned in an earlier posting. The only time that we have trouble negotiating plug headers is when they are of the ‘rolled’ variety, and even some of these are piggable.
Good luck with your tube blockage issue. If we cn be of any assistance, please call.
Pinnacle Pigging Systems
1-403-341-9034 (Linc cellular)