A steam valve is provided with a valve body, a valve seat, and a valve rod provided for the valve body. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. to dehydrogenate the isoamylene to produce isoprene. Using this configuration one can control various quality of service parameters of the requests. An ampule containing a second chemiluminescent fluid is positioned within the enclosed space adjacent to the recess in the closed bottom of the inner cup.