Floating Roof Reel Type Ground

摘要

In a fluid reservoir tank such as an oil tank, the metal roof floats. The American Petroleum Institute (API) Recommended Practice (RP) number 545 requires a floating roof to tank resistance of less than 30 milli-ohms. The improved cable system uses a preferred aluminum braided cable to provide low resistance combined with resistance to sour fluids. Prior art used copper and tinned copper braided cables. The new reel is factory pre-assembled and tensioned using a new cable guide with a cable stop bar which stops a cable stop attached near the end of the (approximately 80 foot) cable. A new spring assembly increased tension and extends cable life by minimizing slack in the cable.

主权项

1. In a fluid/liquid storage tank with a sidewall and a floating roof floating atop the fluid/liquid, an improved grounding system comprising:
a reel connected to the sidewall; said reel having a low impedance conductor for lightning related frequencies connected to the floating roof; said conductor comprising a bare braided aluminum cable; said reel having a take up spool which keeps any slack out of the conductor and maintains a shortest fractional length; said spool having a rewind spring assembly that produces about 80 to about 90 pounds of rewind tension at a maximum payout; said reel having a cable guide with a built in cable stop anchor and a low resistance connection to a spool axle; wherein an excess length of said conductor is wound around said take up spool thereby shorting together adjacent sections of said conductor wound around said take up spool; said conductor having a cable stop; and said reel having a U shaped mounting bracket that bolts to a flat indent on a left end of the spool axle and to a flat indent on a right end of the spool axle.