Opens at 1/2 psi positive OR negative pressure!  Allows your Mono Vault to breathe with changes in elevation, temperature, or weather induced changes in atmospheric pressure.  Also equipped with a recessed manual release button.  Flow rate capacity easily satisfies the industry standard 12% of internal container volume per minute for any Mono Vault.  Installs in 1.02" diameter hole.  Supplied with O-ring seal under face and backing nut.  Made in USA.

We will install your Vault Valve for FREE if purchased along with a Mono Vault.  All factory installed Vault Valves are installed centered on the lid.