FLUID CATALYTIC CRACKING UNIT EXPANSION JOINTS An IMCI Company
CALL TOLL FREE: 1-888-979-FLEX Design and Engineering specializes in the custom design and engineering of FCCU expansion joints. These items require a high degree of technical expertise. Our employees have an average of over 20 years experience in the expansion joint industry. Metal expansion joints are all designed in accordance with Expansion Joint Manufacturers Association (EJMA) standards. When required, expansion joints are also designed to ASME Section VIII Division 1, Appendix 26 and B31.3 Appendix X. Fabric expansion joints used on low pressure ducting are designed in accordance with the Fluid Sealing Association (FSA) guidelines. Solidworks and Solidworks Simulation (FEA) is used to provide accurate modeling and documentation of all products. Customer Service has a clear and overriding objective that our customers should be satisfied with our products, services, prices, and employees. This is embodied in the quality policy, which states: is committed to achieving total customer satisfaction through understanding our customer s need and successfully delivering to our customers high quality and cost effective products, on time every time. This commitment to our customers is further realized by maintaining a practical but comprehensive Quality Management System and implementing its continuous improvement. Quality Assurance System has been certified to ISO 9001 Registration Number FM595125 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 3
WWW.FLEXIDERUSA.COM Overview The FCC process is one of the most important conversion processes in a petroleum refinery. The process converts high molecular weight hydrocarbon fractions of petroleum crude to more valuable products such as gasoline and olefinic gases. Catalyst Due to the high temperatures throughout the FCC process, several expansion joints of various styles and configurations are required for the thermal growth of the high temperature piping. The process diagram to the right and the table below show a typical FCC process and the type of expansion joint typically found in the high temperature piping between vessels or equipment. Expansion Joint (See the FCC Process Diagram for Location) Media Typical Media Temperature (Deg. F) Typical Design Pressure (PSIG) Type of Expansion Joint Metal Bellows or Fabric Expansion Joint Round Piping or Rectangular Ducting 1 Spent Catalyst Standpipe Expansion Joint Catalyst 1,000-1,400 30-100 Metal Round 2 Regenerated Catalyst Standpipe Expansion Joint Catalyst 1,000-1,400 30-100 Metal Round 3 Recirculation Catalyst Standpipe Expansion Joint Catalyst 1,000-1,400 30-100 Metal Round 4 Cooled Catalyst Standpipe Expansion Joint Catalyst 1,000-1,400 30-100 Metal Round 5 Reactor to Main Column Expansion Joint Product 800-1,200 30-100 Metal Round 6 Reactor Riser Expansion Joint Catalyst 1,000-1,400 3-10 Metal Round 7 Regenerator Outlet Expansion Joint(s) 8 3rd Stage Separator Expansion Joint Flue Gas with Catalyst Fines Flue Gas with Catalyst Fines 1,000-1,400 30-100 Metal Round 1,000-1,400 1-15 Metal Round 9 Catalyst Fines Expansion Joint Catalyst 1,000-1,400 30-100 Metal Round 10 11 Expander Inlet or Orifice Chamber Inlet Expansion Joint(s) Expander Outlet or Orifice Chamber Outlet Expansion Joint(s) Flue Gas 1,000-1,400 30-100 Metal Round Flue Gas 1,000-1,400 5 Metal Round 12 Flue Gas Expansion Joints Flue Gas 300-750 < 5 Metal or Fabric Round or Rect 13 Main Air Blower Expansion Joint Air 650 0-100 Metal Round 4 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Typical FCC Process Energy Recovery and Cleaning Single Bellows or Universal Bellows Pressure Thrust Restraining Hardware Typical Piping Material Cold Wall or Hot Wall Configuration Abrasion Resistant Refractory Lining in Hex Mesh Universal Unrestrained Cr-Mo or T304H Hot Wall Yes Insulating Castable Refractory Not Common Two Ply Testable Bellows Slotted Hinges Pantographic Linkages Center Spool Gimbal Limit Rods Floating Rings Yes Yes Yes Yes Yes Yes Universal Unrestrained Carbon Steel Cold Wall NC Yes Yes Yes Yes Yes Yes No Universal Unrestrained Carbon Steel Cold Wall NC Yes Yes Yes Yes Yes Yes No Universal Unrestrained Carbon Steel Cold Wall NC Yes Yes Yes Yes Yes Yes No Universal Tie Rods, Hinge, or Gimbal Cr-Mo Hot Wall No No Yes No No No Yes Yes Single Unrestrained Cr-Mo Hot Wall Yes No No No No No No No Single or Universal Tie Rods, Hinge, or Gimbal Carbon Steel or Stainless Steel Hot Wall or Cold Wall Yes Yes Yes No No No Yes Yes Single Unrestrained Stainless Steel Hot Wall Yes No No No No No No No Universal Single or Universal Single or Universal Single Single or Universal Tie Rods, Hinge, or Gimbal Tie Rods, Hinge, or Gimbal Tie Rods, Hinge, or Gimbal Unrestrained Tie Rods, Hinge, or Gimbal Carbon Steel Cold Wall No Yes Yes No No No Yes No Stainless Steel Hot Wall No No Yes No No No Yes Yes Stainless Steel Hot Wall No No Yes No No No Yes Yes Carbon or Stainless Steel Hot Wall No No Yes No No No Yes No Carbon Steel Hot Wall No No Yes No No No Yes No COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 5
WWW.FLEXIDERUSA.COM Cold Wall Expansion Joints Cold wall expansion joints utilize a high density internal vibracast refractory lining to reduce the design temperature of the shell/piping below the temperature of the internal media. Although the temperature of the catalyst or flue gas may be as high as 1,400 F, the internal refractory lining reduces the shell temperature below 650 F. As a result, carbon steel is usually specified for the piping material of a cold wall expansion joint. Cold Wall Regenerated Catalyst Standpipe Expansion Joint Cold Wall Hinged Expansion Joint for Flue Gas Service (Cross Section View) A B C D E F G H I J 6 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Design Features of a Cold Wall Expansion Joint A. External Insulation: The external insulation elevates the bellows operating temperature above the internal dew point condensation temperature to minimize corrosion on the inner ply of the bellows. The external insulation can be temporarily removed during an outage to allow for inspection of the bellows element. B. Two Ply Testable Bellows: See page 12 of this brochure for additional information on the two ply testable bellows. C. Internal Flow Liner: The downstream end of the internal flow liner operates at the elevated temperature of the catalyst or flue gas, the internal flow liner is fabricated from T304H stainless steel. The upstream end of the liner contains a conical section to allow for the differential radial thermal growth between the cold upstream end of the liner and the hot downstream end of the liner. D. Refractory: High density vibracast refractory insulates the inside of the piping to reduce heat transfer to the expansion joint shell. E. Refractory Anchors: T304H stainless steel wavy vee anchors are used to anchor the high density vibracast refractory lining to the carbon steel shell. F. Liner Gaps: Both the longitudinal and radial gaps at the open downstream end of the liner are sized for the design movements of the expansion joint. These gaps are minimized as much as possible to minimize the amount of catalyst that can enter the liner cavity. G. Liner Seal: The liner seal minimizes the amount of catalyst entering the cavity between internal flow liner and the bellows. The liner seal also protects the structural integrity of the internal insulation. H. Internal Insulation: The internal insulation reduces the bellows operating temperature below the creep temperature and prevents catalyst from packing in the cavity between the internal flow liner and the bellows. I. Abrasion Lining: The cylindrical portion of the internal flow liner is packed with an abrasion resistant lining. It is reinforced by hex mesh (see below). J. Hex Mesh: The inside of the internal flow liner contains a hex mesh lining. Hex mesh is used to anchor the abrasion lining and the refractory in the conical section of the flow liner. COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 7
WWW.FLEXIDERUSA.COM Hot Wall Expansion Joints Hot wall expansion joints are commonly found in the flue gas piping throughout an FCC unit. Hot wall expansion joints between the Regenerator and the 3rd stage separator are usually lined with hex mesh and a abrasion resistant lining to protect the piping from the catalyst fines in the flue gas. Hot wall expansion joints on the inlet and outlet piping of an expander are unlined to eliminate loose pieces of the abrasion resistant lining from traveling through the expander. For both lined and unlined hot wall expansion joints, external insulation is installed around the piping of the expansion joint requiring the expansion joint piping be designed for the full temperature of the flue gas. Hot Wall Single Hinged Expansion Joint Hot Wall Expansion Joint for Flue Gas A B C D E F G H I 8 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Design Features of a Hot Wall Expansion Joint A. Shear Spool: The shear spool transfers the pressure thrust load, and any external design loads, from the external hardware to the line pipe. B. Internal Insulation: The internal insulation reduces the bellows operating temperature below the creep temperature of the bellows material. C. External Insulation: The external insulation elevates the bellows operating temperature above the internal dew point condensation temperature to minimize corrosion on the inner ply of the bellows. The external insulation can be temporarily removed during an outage to allow for inspection of the bellows element. D. Internal Telescoping Flow Liners: The internal telescoping flow liners are a full bore design that reduces the pressure drop of the flue gas flowing through the expansion joint. The internal telescoping flow liners create a cavity for the internal insulation which is critical in reducing the bellows operating temperature. E. Liner Gaps: The opening between the internal telescoping flow liners is located at the center of the bellows to minimize the radial gap needed for the movements of the expansion joint. F. Two Ply Testable Bellows: See page 12 of this brochure for additional information on the two ply testable bellows. G. Expanded Pipe: The smooth transition of the expanded line pipe minimizes the thermal stresses caused by the differential radial thermal growth between the line pipe operating at the full temperature of the media and the insulated bellows element operating at a reduced temperature. H. Floating Ring Retaining Hardware: Pins welded to the outside of the shear spool slide thru corresponding holes in plates welded to the floating rings. These support the dead weight of the floating ring while allowing the differential radial growth between the hotter shear spool and the cooler floating ring. I. Floating Ring: The floating ring is designed to restrain the pressure thrust load and any external design loads. The floating ring concept allows for differential thermal growth between the line pipe operating at the full temperature of the media and the insulated floating ring. Due to insulation installed between the line pipe and the inside of the floating ring, the floating ring operates at a much lower temperature than the line pipe. In many cases the floating ring may be carbon steel even though the flue gas temperature may be 1,450 deg. F, carbon steel is commonly used for the floating ring due to the lower design temperature of the floating ring. The floating ring is not welded directly to the line pipe. COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 9
WWW.FLEXIDERUSA.COM Expansion Joint Hardware Expansion joint hardware is used in expansion joint applications to control movements and loads. Reference the table on pages 4 and 5 for locations where these types of hardware are typically utilized. Gimbal A single bellows gimbal expansion joint is shown at the left. The gimbal hardware allows the expansion joint to absorb angular movement in all planes. Like the hinge, the gimbal hardware is designed to restrain pressure thrust and other external loads. Gimbal expansion joints are used in pairs or in combination with a hinge expansion joint. Single Gimbal Expansion Joint Limit Rods Limit rods are used on many expansion joints to prevent the bellows from moving beyond the designed limit. In these applications the limit rods are not designed to restrain the pressure thrust load. Limit rods are shown in many of the designs on these pages. Limit Rod Hinge A hinged single bellows expansion joint with limit rods is shown at the right. The hinge hardware allows the expansion joint to absorb angular movement in one plane. The hardware is designed to restrain pressure thrust and other external loads. Single Hinged Expansion Joint Gimbal 10 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Pantograph Pantograph linkages equalize the axial movement each bellows of a universal assembly. The gimbal pantograph expansion joint below left absorbs lateral deflection in two planes. The center gimbal ring allows the expansion joint to offset in the opposite plane to the pantograph without the linkage binding. Tie Rods Tie rods are commonly utilized in universal expansion joint assemblies such as the elbow to elbow unit shown above. The expansion joint is capable of absorbing large lateral movements while the tie rods absorb the pressure thrust load. Gimbal Pantograpic Universal Expansion Joint The pantograph linkage above allows for axial movement while supporting the dead weight of the refractory lined centerspool and the catalyst. Elbow to Elbow Tied Universal Expansion Joint COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 11
WWW.FLEXIDERUSA.COM Bellows Design The expansion joint bellows reliability is critical for FCC units as they generally stay on line for long periods of time between shutdowns. For this reason, bellows design incorporates a redundant pressure retaining ply combined with a leak detection hardware. Two-Ply Testable Bellows Typically the bellows is composed of two plies of a material that is capable of handling the full operating pressure alone. The inner ply retains the pressure under normal circumstances. If the inner ply develops a leak, the outer ply then retains the pressure. If this happens the pressure between the plies is ported to a gauge that will then indicate a reading. This alerts personnel to take precautions to repair or replace a failing bellows as soon as possible. A B C D E F G H I Typical Two Ply Bellows with Monitoring Hardware Bellows Features A. Bellows Attachment Weld B. Resistance Weld C. Bracket D. Test Port Pipe E. Pressure Gauge F. Bleed-off Valve G. Bellows Outer Ply H. Wire Mesh Strip I. Bellows Inner Ply 12 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Oversize Clamshell Bellows In the event of a bellows leak through both bellows plies it may be possible to install an oversize clamshell bellows over the existing bellows while the unit is on line. The bellows is supplied in 180 degree segments that are field welded 2 places along the longitudinal seam during installation. The bellows has a weld end that allows attachment to existing end plates. A B C D Bellows Features A. Clamshell Bellows B. Leaking Bellows C. Circumferential Field Attachment Weld D. End Rings The illustration below shows how a typical oversized clamshell bellows is installed in halves over an existing bellows. For a universal typically both expansion joints are covered at the same time to equalize the pressure thrust and spring rates. Universal Pantograph Standpipe Expansion Joint COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 13
WWW.FLEXIDERUSA.COM Hot Wall Universal Gimbal Expansion Joint Cold Wall Standpipe Expansion Joint with Pantograph Hardware Elbow to Elbow Tied Universal Expansion Joint Hot Wall Single Gimbal Expansion Joint 14 COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS
CALL TOLL FREE: 1-888-979-FLEX Tied Universal Expansion Joint Hot Wall Single Hinged Expansion Joint Fabric Expansion Joint Metal Rectangular Expansion Joint COPYRIGHT 2014 FLEXIDER FCCU EXPANSION JOINTS 15