TubeNet

http://cgi.ebay.com/1903-Compensating-C ... 952wt_1396" target="_blank
Compensating? Cool!

Neat! However, it's not compensated, just convoluted. Follow the air: the lead pipe enters the second valve, then proceeds to the first (through that loop that the seller mistakes for compensating loop) and another loop brings it from first to third. Also note the lack of extra ports in the valves.