API Spec 12P:2008 pdf download

API Spec 12P:2008 pdf download.Specification for Fiberglass Reinforced Plastic Tanks.
FPR flanged nozzle construction and design shall conform to ASTM D3299. Table 4. Flange dnlling and boltmg shall conform to ANSI Bi 6.5 for Class 150 flat faced flanges,
All fittings below liquid level shall be reinforced internally with at least two layers of 1.5 ozift2 mat. The inner surface shall be sealed according to 4.4.1 of this specification.
4.14 Walkway, Ladder, Lifting and Hold Down Lugs
The manufacturer shaM demonstrate by physical test that all lugs are capable of withstanding two times the allowable service load. The service load for each lifting lug equals the empty weight of the tank. Lugs shall not be installed by the use of fasteners that penetrate the sheM. Walkway and ladder loads are specified In Annex B.
If hold-down (wind anchorage) lugs are specified by purchaser, the manufacturer shall use ANSI A58.1 to calculate wind loads. Hold-down lugs shall be placed on the tank so they do not protrude below the bottom surface of the tank.
4.15 Downcomer Pipe
A conductive downcorner pipe shall be installed when specified in the datasheet,
4.16 Thief Hatches
Thief hatch pressure and vacuum ratings shall be in accordance with the design conditions (see 4.1), Bolt patterns shall conform to one of those shown in Figure 4. A grounding lug shall be installed on the thief hatch for grounding purposes. The lug si,ze shaM accommodate the attachment of a No. 4 wire. A striker plate consisting of a minimum of 0.1875 in. 16 in. x 16 in. steel material shall be laminated to the tank bottom directly below the thief hatch.
4.17 Design Considerations for Potential Electrostatic Hazards
The electrostatic hazards which might anse when filling 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 mlnim4ze the risk ii the first type of hazard, it is recommended that the thief hatch be connected to electncal ground. It is also recommended that any metallic walkway, stairway, or ladder attached to an FRP tank be connected to electrical ground.
To minimize risk of the second type of hazard there are several different options to consider. As in metal tanks, the primary method utilized to minimze charge accumulation inside the tanks Is to limit flow rates until the filling pipe is covered. The use of conductive metallic downcomers shall also be considered. Conductive tank materials used in tank construction and property grounded can also be utilized as specified in datasheet. In severe cases the use of a suspended conductor within the tank can be used (see FIgure 5).