##
Conservation Vent Valve is a device designed to maintain pressure within preset
limits in a liquid-containing vessel for the purpose of emissions reduction. It
also provides protection against excessive pressure or vacuum.
=
Because of its primary function, a pressure/vacuum valve is commonly referred
to as a breather valve or “Pressure/Vacuum Relief Valve (PVRV)“.
=
It’s a protection device mounted on a nozzle opening on the top of a fixed roof
atmospheric storage tank.
=
It’s to protect tanks against rupturing or imploding. Without an opening or a
controlled opening, a fixed roof atmospheric tank would rupture under
increasing pressure caused by pumping liquid into the tank or as a result of
vapor pressure changes caused by severe thermal changes. Imploding, or the
collapsing of a tank,occurs during the pumping out procedure or thermal
changes.
=
It’s employed where it is necessary or desirable to reduce evaporation of tank
contents to atmosphere.
=
These vents are generally designated as the conservation type. They are
typically mounted to a flange or pipe that connects to the vapor space (space
within the tank that is above the liquid surface)
=
The pressure in this vapor space increases or decreases as liquid is pumped
into or out of the tank, respectively.
Comments
Post a Comment