The unit is fitted with an additional spring-loaded vacuum valve that will open under negative pressure, protecting the tank from any over-vacuum damage.

They are used extensively on bulk storage tanks.

122 Series are manufactured by MTP in our UK manufacturing plant to exacting quality standards and backed by over 40 years experience. Sizes range from 18″ (450mm) to 24″ (6000mm).

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.