Safety valve

Spun glass mattresses are used for lagging the boiler, which has three Ross pop safety valves on the front ring.

[A]nd to show that there was no shortage of steam, Royal Scot, directly we stopped, blew off vigorously from its safety-valves steam that well might have been used in the cylinders in the interest of timekeeping.

[…] I have often thought that it was a great error in our legislature when they consented to put down the public lotteries in England. I am convinced that they were beneficial, acting as safety-valves to the gambling spirit of the nation, and that their prohibition has been productive of much crime and misery.

Hernández additionally requested that he be given a two-level safety-valve reduction pursuant to U.S.S.G. § 5C1.2, which mitigates the harsh effect of mandatory minimum sentences on certain first-time offenders who played only supporting roles in drug-trafficking schemes and who provided testimony about their involvement in the criminal activity.