There's no valve in the pipe - it's straight through. The accordian folds are for thermal expansion and alignment forgiveness, but seem to later become the area that weakens and splits from fatigue and/or thermal cycling. You can make one from copper tubing and braze it to the remains of the original. One way would be to cut out the bellows and slip the remaining ends inside a piece of copper tubing used as a sleeve. You might even be able to solder the pieces together if the joint is tight enough.

AFAIK, the only valve in the system is the EGR valve on the intake manifold, but I think M/T models and perhaps CA emissions models may have a thermo sensor included.

Frank