Here is something you've never seen before. It is the manual release valve for the Rinse Section Pressure Rollers. When pushed in, the rollers are lifted away from the bolster rolls; in the pulled position, the rollers are locked down to operate.
On all machines built prior to 1992, including ours, the rinse rollers are controlled by the "main air solenoid" in the cabinet. When the operator hits the STOP button, that solenoid shuts off, and the rollers release... allowing 10 to 15 yards of wet, unextracted towel to be pulled out onto the drying drums as the machine coasts to a stop, as well as letting the guillotine to drop.
This makes it take longer to restart the machine, as the operator has to pull enough towel into the clean-side accumulator, or "stacker", to raise the guillotine to the top, and makes for damp, soapy towels in the system, which will need to be rewashed. A typical stop can take several minutes to restart.
With the new system, the rollers stay put, which keeps the wet towel off the drying drums, slows the machine to a stop faster, and does not allow the guillotine to drop. Restarting the machine is nearly instantaneous, raising operator productivity and reducing rewash.
There is also a manual release valve on the Stacker Drive, so that tension is never lost.
In the event of a towel break, the valves are conveniently placed to allow the operator to release only the rollers closest to the break, as needed to fix it. And, since a pressure switch in the control panel knows when either valve is pushed, they can also act as additional emergency stop buttons; a simple push brings the machine to a halt.