Calibration of Floating Roof Storage Tanks-Reg

Your homework should come with a diagram that explains this structure.

Also, we don't do homework.

A tank is a tank is a tank. What on Earth needs calibrating?

All very interesting. So how does this relate to the original poster's query when the question asked relates to a tank the size, shape, contents, temperature, pressure, configuration of which and the need for which have not been revealed?

To answer your question, I refer to Solar Eagle beautiful reference link where everything is explained in full. It will take a while to work through it.

Since the OP asks about a tank with a floating roof, only hydrostatic pressure + weight of the roof.

The need is for safety reasons -a burning tank is a nightmare, a leaking tank a loss and a collapsing tank to avoid. Great Britain had one of the world's biggest tank fires ever and each tank has to have a well kept logbook to contain the risks and determine the de- commissioning. I just found that stating a tank is a tank, needed some elaboration. Probably my bad character. All the best. D.

A floating roof suggests that the cross-section is uniform from bottom to top; hence, volume is proportional to depth. V = KdA.

I worked in pipeline fuels for over a decade. My experience is mostly in operations and not construction or maintennace so I can't say much about calibration.

The long leg and short leg refers to the landing legs that suppor the floating pan when the tank is empty. It is usually kept on short legs unless someone will need to go under the pan after the tank is empty (for work / cleaning / inspections). The legs go through the pan and are held in with pins. We had heavy duty 'socks' that fit over the legs to prevent evaporative losses and water intrusion.

We only took level readings when the roof was drained of water. All of the tanks I worked on had an open drain that was affixed to the roof and went through the fuel in a hinged pipe and emptied into the diked in area. We inspected the drains for signs of product and leaking hinges. Only once did I find a tank that had a plugged drain that had accumulated about 2 ft of water on top of the floating pan.

We used automatic tank gauging equipment for most accounting purposes but would calibrate the ATG monthly by 'sticking' the tanks with a metal tape. With floating pan or cone roof tanks, we used the depth of the fuel on the tape and I didn't do anything to account for the floating pan. We did adjust the quantity by a volume correction factor with regard to temperature; fuel was accounted for as if it was at 60° F.

The floating roof was constructed of separated sections and we also inspected the 'pontoons' by lifting an open lid and looking for water or fuel.

Drew K