The unit is fitted with an additional spring-loaded vacuum valve that will open under negative pressure, protecting the tank from any vacuum damage.
They are used extensively on bulk storage tanks.
122 Series are supplied by IPTech Tank Protection to exacting quality standards and backed by over 40 years experience. Sizes range from 18″ (450mm) to 24″ (600mm).
MTP 122 Series non-sparking emergency relief manhole covers permit access to low pressure storage tanks and provide emergency venting capacity in the event of fire.