API RP 572:2009 pdf download

API RP 572:2009 pdf download.Inspection Practices for Pressure Vessels.
3.1.20
on-stream
A condition whereby a pressure vessel has not been prepared for internal inspection and may be in service.
3.1.21
owner-user
An owner or user of pressure vessels who exercises control over the operation, engineering, inspection, repair, alteration, testing, and rerating of those pressure vessels.
3.1.22
pressure design thickness
Minimum wall thickness needed to hold design pressure at the design temperature as determined using the rating code formula. It does not include thickness for structural loads, corrosion allowance or mill tolerances.
3.1.23
pressure vessel
A container designed to withstand internal or external pressure. This pressure may be imposed by an external source, by the application of heat from a direct or indirect source, or by any combination thereof. This definition includes heat exchangers, air-coolers, unfired steam generators and other vapor-generating vessels which use heat from the operation of a processing system or other indirect heat source.
3.1.24
pressure vessel engineer
One or more persons or organizations acceptable to the owner-user that are knowledgeable and experienced in the engineering disciplines associated with evaluating mechanical and material characteristics that affect the integrity and reliability of pressure vessels. The pressure vessel engineer, by consulting with appropriate specialists, should be regarded as a composite of all entities necessary to properly address a technical requirement.
3.1.25
repair
The work necessary to restore a vessel to a condition suitable for safe operation at the design conditions. If any of the restorative work results in a change to the design temperature, MDMT, or MAWP, the work shall be considered an alteration and the requirements for rerating shall be satisfied. Any welding, cutting, or grinding operation on a pressure-containing component not specifically considered an alteration is considered a repair.
3.1.26
rerati n g
A change in either the design temperature rating, the MDMT, or the MAWP rating of a vessel. The design temperature and MAWP of a vessel may be increased or decreased because of a rerating. Derating below original design conditions is a permissible way to provide for additional corrosion allowance.
3.1.27
risk-based inspection
RBI
A risk assessment and management process that is focused on inspection planning for loss of containment of pressurized equipment in processing facilities, due to material deterioration. These risks are managed primarily through inspection in order to influence the probability of failure.
3.1.28
strip lining
Strips of metal plates or sheets that are welded to the inside of a vessel wall. Normally, the strips are of a more corrosion-resistant or erosion-resistant alloy than the vessel wall and provide additional corrosion/erosion resistance.
Metallic liners are installed in various ways. They may be an integral part of the plate material rolled or explosion bonded before fabrication of the vessel. They may instead be separate sheets of metal fastened to the vessel by welding. Corrosion-resistant metal can also be applied to the vessel surfaces by various weld overlay processes. Metallic liners may be made of a ferritic alloy, Alloy 400, nickel, lead, or any other metal resistant to the corrosive agent. Figure 1 through Figure 4 show various methods of applying metallic linings. Figure 5 and Figure 6 show the Hex mesh installation to support the refractory lining and the reinforced refractory lining.
Nonmetallic liners may be used to resist corrosion and erosion, reduce fouling potential (i.e. exchanger tubes), or to insulate and reduce the temperature on the walls of a pressure vessel. The most common nonmetallic lining materials are reinforced concrete, acid brick, refractory material, insulating material, carbon brick or block, rubber, phenolic/ epoxy coatings, glass, and plastic.
Pressure vessels constructed out of nonmetallic materials are usually made from fiber reinforced plastic (FRP) and can be more resistant to some corrosive services. FRP can be made with different resins as the matrix material and typically use glass fiber as the reinforcement. Reinforced thermoset plastics are a type of FRP that is more rigid due to the use of a thermoset resin for the matrix rather than a thermoplastic. Both of these nonmetallic materials have varying strength due to the type of fiber used, fiber weave, and the lay-up of the fiber layers.