MH/T 6115-2017The excellent equipment technical requirement of internal aluminum floating roof for commercial aviation fuel tank (English PDF)

4.1 Skeleton

4.1.1 The bolts connecting the skeleton and the skin plate shall not be loose or missing.

4.1.2 All aluminum profiles should not have obvious deformation, cracking and damage. The straightness of the main and auxiliary beams should not be greater than 1 per mille of their length and not greater than 1 mm.

4.2 Skin board

4.2.1 The skin panel should not be damaged, twisted or wrinkled.

4.2.2 The skin board and the bead should be tightly connected, and there should be no gaps. It can be inspected by strong light, and it is qualified if it is opaque.

4.2.3 The local corrosion depth of the skin plate should not exceed 1/2 of the thickness of the skin plate.

4.3 Float

There should be no pits or perforations on the surface of the buoy, no distortion or wrinkles in the welding part of the buoy, and no oil infiltration inside the buoy, otherwise should be replaced.

4.4 Peripheral sealing device

4.4.1 The peripheral sealing device should be closely attached to the inner surface of the tank wall, and its sealing length should not be less than 90% of the circumference of the storage tank.

The maximum gap does not exceed 6 mm.

4.4.2 The sealing rubber belt should be free of damage or cracks.

4.4.3 The sealing rubber band and the edge plate of the inner floating roof should be connected tightly without loosening or peeling.

4.4.4 The sealing rubber belt should be wear-resistant and oil-resistant.

4.4.5 The service life of the sealing rubber belt should not exceed 6 years.

4.4.6 The structure of the peripheral sealing device is shown in Figure 3.

4.5 Support column

4.5.1 The support column and the internal floating roof frame should be firmly connected.

4.5.2 When the inner floating roof drops to the bottom, any support pillars should not be suspended.

4.5.3 The body of the support column should not be significantly bent, and its straightness should not be greater than 1 mm.

4.5.4 The verticality deviation between the support column and the inner floating roof should not be more than 3 per mille of the support height (as shown in Figure 4).

4.5.5 The rubber gasket at the foot of the support column should be firmly attached and completely cover the bottom surface of the support column, the split pin should be complete, and the lower end of the drain should be unobstructed.

4.5.6 The support column should not be in contact with any accessories in the tank such as tank bottom pipelines and floating oil outlets.

4.6 Automatic ventilation valve

4.6.1 When the inner floating roof is in a supporting state, the opening height of the automatic vent valve should be 150 mm ~.200 mm (as shown in Figure 5).

4.6.2 The valve stem of the automatic vent valve should move smoothly.

4.6.3 The valve cover and valve housing of the automatic vent valve should be well sealed and should not be deformed or damaged.

4.6.4 The rubber gasket at the lower end of the valve stem of the automatic vent valve should be firmly attached and completely cover the bottom surface of the valve stem, the split pin should be complete, and the drainage should be unobstructed.

4.7 Anti-rotation device

4.7.1 The anti-rotation wire rope should be taut, and the horizontal swing should not exceed 50 mm.

4.7.2 The verticality deviation of the anti-rotation wire rope should not be more than 1 per mille of its length, and should not be more than 10 mm.

4.7.3 The wear depth of the wire rope casing should not be greater than 1 mm, otherwise the casing should be replaced and the casing installation position adjusted.

4.7.4 The wire rope should be intact and there should be no broken wires.

4.7.5 The connection tie between the steel wire rope and the base should be locked tightly without looseness.

4.7.6 The welded joint between the base and the bottom of the storage tank should be intact, free of welding and cracks. The welding place should avoid any welding seam on the bottom of the tank.

4.7.7 Check whether the tension springs and tie rods are corroded. If the corrosion is serious, replace them in time.

4.7.8 The pull rod and pipe cap at the top of the wire rope should be detachable freely.

4.7.9 The schematic diagram of a single anti-rotation device is shown in Figure 6.

4.8 Electrostatic conductive device

4.8.1 The electrical connection between the static conductive stainless steel wire rope and the inner floating roof and tank top should be reliable. Special electrical connection made of stainless steel should be provided at the connection both ends of the terminal are fixed with two stainless steel bolts no smaller than M10 plus anti-loosening washers and double nuts.

4.8.2 The static conductive stainless steel wire rope should not be twisted, knotted or broken.

4.8.3 The length allowance of the static conductive stainless steel wire rope should not be less than 1 000 mm.

4.9 Oil measuring hole

4.9.1 The deviation between the center of the inner floating roof oil measuring hole and the center of the tank top oil measuring hole should not be more than 5 mm. The dipstick put in from the Apparatus such as sampler, temperature measuring box, etc. should be able to pass through the inner floating roof oil measuring hole unobstructed.

4.9.2 The rubber skin of the opening of the oil measuring hole should be kept in a horizontal state without aging and sagging (as shown in Figure 7.Figure 7a) shows the state of the rubber skin Good, Figure 7b) shows that the rubber watch is aging and sagging).

4.10 Manhole

4.10.1 The opening and closing state of the manhole cover shall be intact.

4.10.2 The manhole climbing ladder should be welded firmly without looseness.

4.10.3 The sealing tape should be complete, and the closed state should be sealed.

4.10.4 The schematic diagram of the manhole is shown in Figure 8.