API Spec 12P:2008 pdf download

API Spec 12P:2008 pdf download.Specification for Fiberglass Reinforced Plastic Tanks.
4.13Appurtenances
Nozzles, cleanouts, and other appurtenances shall be installed in accordance with 4.14.Installation laminates shallmeet minimum standards shown in Figure 5 and Figure 6 of ASTM D3299.
FPR flanged nozzle construction and design shall conform to ASTM D3299,Table 4.Flange drilling and bolting shallconform to ANSI B16.5 for Class 150 flat faced flanges.
Allfittings below liquid level shall be reinforced internally with at least two layers of 1.5 oz/f- mat. The inner surfaceshall be sealed according to 4.4.1 of this specification.
4.14Walkway,Ladder,Lifting and Hold Down Lugs
The manufacturer shall demonstrate by physical test that all lugs are capable of withstanding two times the allowableservice load.The service load for each lifting lug equals the empty weight of the tank. Lugs shall not be installed bythe use of fasteners that penetrate the shell. Walkway and ladder loads are specified in AnnexB.
lf hold-down (wind anchorage) lugs are specified by purchaser, the manufacturer shall use ANSIA58.1 to calculatewind loads. Hold-down lugs shall be placed on the tank so they do not protrude below the bottom surface of the tank.
4.15Downcomer Pipe
A conductive downcomer pipe shall be installed when specified in the datasheet.4.16Thief Hatches
Thief hatch pressure and vacuum ratings shall be in accordance with the design conditions (see 4.1). Bolt pattermsshall conform to one of those shown in Figure 4. A grounding lug shall be installed on the thief hatch for groundingpurposes.The lug size shall accommodate the attachment of a No.4 wire. A striker plate consisting of a minimum of0.1875 in. x 16 in. x 16 in. steel material shall be laminated to the tank bottom directly below the thief hatch.
4.17Design Considerations for Potential Electrostatic Hazards
The electrostatic hazards which might arise when filing or emptying FRP tanks may be divided into two parts:1) that due to the accumulation of charge on the outside of the tank;
2) that due to the build-up of electric field inside the tank.
To minimize the risk in the first type of hazard, it is recommended that the thief hatch be connected to electricalground. lt is also recommended that any metallic walkway, stairway, or ladder attached to an FRP tank be connectedto electrical ground.
To minimize risk of the second type of hazard there are several different options to consider. As in metal tanks, theprimary method utilized to minimize charge accumulation inside the tanks is to limit flow rates until the filing pipe iscovered. The use of conductive metallic downcomers shall also be considered.Conductive tank materials used intank construction and properly grounded can also be utilized as specified in datasheet. In severe cases the use of asuspended conductor within the tank can be used (see Figure 5).
a) The internal surface shall be smooth, free of cracks and crazing and shall contain no more than 2 pits per 1 ftsquare area.Acceptable pits shall be less than 1/8(3.2 mm) in diameter and less than 1/2 (0.8 mm) deep.Acceptable pits shall be covered with sufficient resin to assure coverage of the inner surface reinforcement. Pits oflarger dimensions are not acceptable and shall be repaired.Some waviness is permissible as long as the surfaceis smooth and free of pits.
b) The exterior surface shall be smooth and free of exposed fibers.6.2Hydrostatic Testing
Tanks shall be hydrostatically tested in the manufacturer’s shop or conducted in the field after installation as specifiedon the datasheet.
Tests shall be conducted with clean fresh water to which a surfactant has been added.Tests shall be held for a minimum of 4 hours.
Tanks shall be tested by filling 12 in.above the top crown of the tank through use of a temporary standpipe.
All connections shall be plugged or blinded during the test with the type and size fittings intended for use afterinstallation, to conform thread or flange sealing integrity.
Any leaks or defects found shall be repaired by the manufacturer and the tank retested for a minimum of 2 hours.6.3Quality Control Tests
Tests shall be conducted on the completed tank to confim that this standard is met. At a minimum, these includethickness, degree of cure, dimensional tolerances,and surface cure.
Vessel thickness shall be measured and recorded at all cutouts to verify specified minimum thickness is met orexceeded.Readings shall be taken utilizing a micrometer or calipers at four positions,90 degrees apart at eachcutout.
Degree of cure of the laminate shall be determined to meet resin manufacturer’s standards by measuring Barcolhardness in aocordance with ASTM D2583.
Tank dimensions and standard nozzle locations shall be verified on the finished tank to meet the tolerances of Table 1and locations on Figure 3.