safety valve

IPA: sˈeɪftivˈæɫv

A valve set to open at a pressure below that at which a container holding a gas, vapour, etc. (such as a boiler or pressure cooker), would burst, thus reducing the pressure; a relief valve.
(by extension) A valve set to close a container holding a gas or vapour to prevent excessive loss of pressure.
(figuratively) Any mechanism offering relief from physical or emotional pressure or tension.
(US, law) A United States law, codified at 18 United States Code §3553(f), authorizing a judge to disregard mandatory minimum sentences for some criminals with few or no prior offenses.

safety-valve

IPA: sʌfˈɛtivˈɑɫv

Alternative form of safety valve [A valve set to open at a pressure below that at which a container holding a gas, vapour, etc. (such as a boiler or pressure cooker), would burst, thus reducing the pressure; a relief valve.]

Sometimes followed by off:
To use a relief valve on (a container holding a gas or vapour) to relieve excessive pressure which has built up inside.
To install a relief valve on (such a container) for that purpose.
(figuratively) To use some mechanism to relieve (physical or emotional pressure or tension).

Here are my top four “Plan B” safety-valve ideas if ObamaCare passes:
Schopenhauer's statement also condemns our press for its failure to serve as a "safety-valve" for democracy.
But now that I have some “Plan B” safety-valve ideas, I am feeling much better should Obamacare come to pass.
In other words, no regulator has the omniscience to decide which plants are "must run" and therefore deserving of a safety-valve exemption.
There is a safety-valve idea #5″ I am considering should ObamaCare pass, but it is kind of humiliating, and I would need the help of my wife.
In full it reads: Freedom of the press is to the machinery of the state what the safety-valve is to the steam engine: every discontent is by means of it immediately relieved in words--indeed, unless this discontent is very considerable, it exhausts itself in this way.
A second example -- that warms the hearts of economists, but appears to be politically irrelevant for the time being -- is the case of a Federal policy that sets price, not quantity, i.e., a carbon tax, or a binding safety-valve or price collar in a cap-and-trade system.
Importantly, trading brought about by unrestricted links between CAT systems will lead to the automatic propagation of certain design elements, including: offset provisions and linkages with other systems; banking and borrowing of allowances across time; and safety-valve provisions.