API Std 650 uplifting tanks reinforcement of weld

All API Std 650 uplifting tanks fillet welds shall consist of a minimum of two passes. The ends of the fillet welds shall be 2 in. from the rat hole, and these welds shall be deposited by starting 2 in. from the rat hole and welding away from the rat hole. An acceptable alternative to stopping fillet welds 2 in. short of the rat hole would be to weld continuously through the rat hole from one side of the stiffener to the opposite side. All craters in fillet welds shall be repaired by back welding.

Upon completion of API Std 650 uplifting tanks construction, provide Purchase with a Vendor's Certification that the tank conforms to the requirements of API 650 and to the additional requirements as specified.

The lip seal of floating roof storage tank, API Std 650 uplifting tanks relies on the sliding contact between elastic lip and tank wall. This kind of seal has strong applicability, but the requirements of manufacturing technology and material selection are high, and the determination of elastic seal also exists. The secondary seal of floating roof storage tank, API Std 650 uplifting tanks is to add a seal on the basis of primary seal. It is proved by experiments that the secondary seal can reduce the liquid consumption by more than 50%, and has a more significant effect in safety.