© ABB Lummus Global Confidential ABB Lummus Global Inc. Lummus Technology Division Pyrolysis Heater Operation and Maintenance Heater Maintenance ◼ Basic Heater Operation Principles ◼ General Arrangement ◼ Radiant Section ◼ Coil ◼ Refractory © ABB Lummus Global Confidential ◼ Suspension ◼ Burners Heater Maintenance ◼ Convection Section ◼ Coils / Piping ◼ Crossover Piping ◼ TLE’s ◼ Primary © ABB Lummus Global Confidential ◼ Secondary ◼ ID Fan © ABB Lummus Global Confidential Basic Heater Operation Principles Basic Heater Operation Principles ◼ Pyrolysis ◼ Heating of a hydrocarbon molecule to a temperature that causes it to “crack”, or decompose into smaller molecules. ◼ Naphtha – H2+Ethylene + Propylene +Butadiene + Benzene + Gasoline ◼ Very high Temperature – ca. 830oC © ABB Lummus Global Confidential ◼ Low Pressure – ca 100 Kpa (Abs) ◼ Significant byproducts, such as pytar/coke Basic Heater Operation Principles ◼ Pyrolysis – cont’d ◼ Hydrocarbon feed is “diluted” with steam ◼ Reduces HC pressure ◼ Minimizes deposition of tar/coke ◼ The reaction is contained within the “radiant coil” © ABB Lummus Global Confidential ◼ And cooled to a temperature that stops the reaction in the “TLE”, which boils water to make “Super” high pressure steam. Basic Heater Operation Principles ◼ Pyrolysis – cont’d ◼ The radiant coil is designed for very low pressure drop, and is designed for operation at a maximum metal temperature of 1125oC (melting point of steel is 1375oC) ◼ TLE is a special design heat exchanger designed for very high inlet temperature © ABB Lummus Global Confidential ◼ Thin tubesheet cooled by water/steam © ABB Lummus Global Confidential General Arrangement General Arrangement – Side View ID Fan/Stack Steam Drum Convection Section Primary TLE’s © ABB Lummus Global Confidential Wall Burners Radiant Section Hearth Burners General Arrangement – Front View ® STACK ID Fan/Stack A CCE S S DOOR Ÿ 50 0 OP E NI NG 3 00 1 00 0 ® TLE ® TLE ® TLE ® TLE ® TLE ® TLE A CCE S S DOOR 1 00 0 3 00 E L+ 2 7 98 6 UFP I . 1 /2 / 3 ™6 + 5 0 I NS . ™. 6 + 5 0 I NS . C. T. C CLE A NING DOORS E L+ 2 5 68 6 B FW I C/ C T UBE S UPP ORTCOL UM NS F OR UP PE R CONV E CT I ON S E CTI ON 3 75 E L+ 2 4 61 6 B FW O Convection Section E L+ 2 4 41 1 D. 1 / 2 / 3 VARIABL E SPRIN G HANGERS (3 X) SEE DWG.BA 1 0 3 4 00 VARIABL E SPRIN G HANGERS (3 X) SEE DWG.BA 1 0 3 (B OT H HE A DERB OXE S ) E L+ 2 2 07 5 UPO. 1 / 2/ 3 E L+ 2 1 50 5 USO E L+ 2 1 20 5 M SI E L+ 2 0 54 5 L SO 4 30 1 34 1 5 00 ACCESS DOOR Ÿ 5 0 0OPEN. 3 74 0 RO. 1 RO. 2 ACCESS DOOR Ÿ 5 0 0OPEN. 3 74 0 C. T. C CLE A NING DOORS 4X 4X 3 31 1 RO. 4 RO. 3 4X 4 17 6 RO. 5 4X 1 34 1 8 50 3 00 RO. 6 4X 4 17 6 4X 4 17 6 ™. 6 + 7 5 I NS . 3 31 1 C/C TUBE SUPPORTS FOR L OW E R CONV. S E CT . 720 430 ™. 6 + 7 5 I NS . ™6 + 7 5 I NS . 4 30 ™. 6 + 7 5 I NS . 3 00 8 50 Primary TLE’s DI VI DE R P L A TE B ET W E EN UPP E R ST E A M S UPE RHEA T DESUPERHEATER 3 11 L OCATION OF PEEPHOL ES 1288 4 1219 2 EXPOSED LENGTH HEA T E R S Y M M E T RI CA L A BOUT THI S CE NT ERL I NE UNL E S S OT HERW I SE S HOW N OR NOT E D. 381 Radiant Section L OCA T I ON OF S I DE W AL L B URNE RS . 510 © ABB Lummus Global Confidential UPPER TWO(2 )ROWS L OCA T I ON OF DE COK I NG 1 31 2 1 76 8 1 31 2 ROW S OF P E EP HOLE S (S EE K EY P L AN) SEC TIO N B-B © ABB Lummus Global Confidential Radiant Section SL-2 Coil Radiant Coil ◼ SL – 2 Coil ◼ Each coil has two “passes” ◼ Pass one has 16 parallel tubes 63.5 mm ◼ 25/35 and 35/45 Ni/Cr Microalloy ◼ Pass two has 4 parallel tubes 120.8 mm ◼ 35/45 Ni/Cr Microalloy © ABB Lummus Global Confidential ◼ Total of 6 coils/heater Radiant Coil ◼ SL-2 Coil © ABB Lummus Global Confidential Inlet Passes Inlet Passes Outlet Passes Radiant Coil ◼ SL-2 Coil ◼ Each coil has an inlet manifold, located on top of the firebox ◼ Each manifold is supported by an “A” frame with a large counterwieght © ABB Lummus Global Confidential ◼ Each tube is connected to the manifold through an “inlet finger” which contains a venturi to maintain even flow to each inlet tube Radiant Coil 140 SEE DW G . BA120 (T YP.) « T LE 1ü"x SCH. 40 A312-TP347 F IELD ASSEM BLED 1140 563 T YP. 417 PRESSURE T AP (4x) SEE DET . 4 (T YP) 417 (12x) T YP. SEE DW G . BA124 980 SHO P W ELD (T YP.) T YP. 723 140 160 == Inlet Manifold (4x) T YP. A 8"x SCH. 80S A312-TP347H INST RUM ENT SUPPO RT F RAME BY O THERS © ABB Lummus Global Confidential SET O N W ELD SEE DET .1 (TYP. ) SHO P ASSEM BLED 680 SEE DET .2 (T YP.) A 600 600 SEE DET AI L 5 PLAN CRO SS0VER SEE DW G . BA135 Flow Distribution From Convection Section P Sonic Velocity © ABB Lummus Global Confidential P= 2.1 PSI W 2L D5 PD W L D 2 1.9 Flow 1000 880 5 Venturi Monitoring ◼ At Constant HC Feed, S/O and XOT Venturi Inlet Pressure Should Remain Constant Throughout the Run ◼ Venturi Inlet Pressure Should Be Essentially Equal for All Coils if Flow is Equal ◼ Venturi Pressure Ratio < CPR ◼ Terminate Run If Any of the Following Occur ◼ Venturi P Less Than (1-CPR) x Absolute Inlet Pressure ◼ Any Significant Increase in Venturi Inlet Pressure (If P © ABB Lummus Global Confidential Measurement is Not Available) ◼ Rapid Decrease in Venturi P Radiant Coil Radiant Outlet Thermowell ASSY © ABB Lummus Global Confidential Thermowell Should be rotated 90o After Every Decoke Metallurgy ◼ Furnace tubes are Alloys of Iron (Fe), Nickel (Ni), Carbon (C), Chromium (Cr), Silicon (Si), Molybdenum (Mo), and Tungsten (W) © ABB Lummus Global Confidential ◼ Additions of Niobium (Nb), Titanium (Ti), Zirconium (Zr), Tantalum, Cerium (Ce), Hafnium, and Lanthanum. Metallurgy Metals are Crystalline Structures © ABB Lummus Global Confidential All Metals Have Dislocations The Movement of Dislocations Allows Metals to Deform Metallurgy ◼ Metals are Strengthened by Inhibiting the Movement of Dislocations ◼ Improved Solution Strength ◼ e.g. Add Nickel ◼ Precipitation of Secondary Phases and Metallic Carbides Where M is Chromium, Titanium, Niobium, and Tungsten © ABB Lummus Global Confidential ◼ MxCy © ABB Lummus Global Confidential Metallurgy Ni Cr C Si W Mo Al Nb, Ti, Zr, Ta Ce, Ha, La 25-50% 25-35% 0.4-0.6% 1-2% 2-5% 1-3% <2% Small <0.05% Composition of Cracking Heater Tube Alloys Pompey Pompey Kubota HP- 40 Mod HP- 40 W Manaurite XM Manaurite XTM KHR 45A CR 23.5/26.5 24/27 23/28 34/37 30/35 Ni 34/37 33/37 33/38 43/48 40/46 Si 1.5/2.0 1.5/2.0 1.0/2.0 1.0/2.0 2.0 max. Mo 1.25 max. 1.5 max. 1.0/1.5 1.0/2.0 2.0 max. C 0.37/0.45 0.37/0.50 0.37/0.50 0.40/0.45 0.40/0.60 W - 3.8/5.0 - - - Additions W, Nb - Nb, Ti, Zr Nb, Ti TI + others + others + others © ABB Lummus Global Confidential Element 0 % of Plants 20 HK-40 OTHER 35CR-45Ni 25CR-35Ni HP-40M WELDABILITY RUPTURE BULGING CREEP PLUGGING BOWING AGE CARBURIZATION © ABB Lummus Global Confidential Radiant Coil Coil Replacement Criteria for Various Metallurgies 100 80 60 40 Tube Material Selection ◼ To Avoid Excessive Creep, Axial Stress Due to Weight plus Pressure should not control wall thickness © ABB Lummus Global Confidential P Weight ◼ This Will Limit Tube Length for Any Given Material Primary Tube Stresses Axial Stress P Axial Force Due to Pressure = P 2 D = Fp 4 Circumferential (Hoop) Stress L © ABB Lummus Global Confidential W Initial Elongation © ABB Lummus Global Confidential Extension Creep Linear Secondary Creep 0 0 Time Creep Strength © ABB Lummus Global Confidential ◼ Distortion ◼ Ovalling of Tube Cross Section Due to Creep ◼ Elongation Creep Distortion (Flat Section) Carburization Carbon Diffuses into the Metal Forming Cr23C7 Which in Turn Forms Cr7C3 Gradually Carburizing the Tube Wall © ABB Lummus Global Confidential Carbon Carburization Carburization Makes the Metal Strong but Brittle The Volume Also Increases Causing Stress © ABB Lummus Global Confidential The Tube Bulges and Fails Tube Life The End of a Tube’s Useful Life is Determined by: ◼ Correlation of the Magnetic Properties ◼ 5-7% Bulge in the Diameter or a Bulge with a Dimple ◼ 1% Carbon in the Surface Metal of the O.D. ◼ Sampling and Measuring the Extent of © ABB Lummus Global Confidential Creep Voids © ABB Lummus Global Confidential Radiant Section Refractory Refractory System Ceramic Fiber “Z-Block” © ABB Lummus Global Confidential Insulating Fire Brick Castable Ceramic Fiber “Blanket” Refractory System ◼ Typical Problems ◼ Ceramic Fiber will shrink after initial Firing/Dryout ◼ Important to Shut Down and Inspect Insulation before beginning Operation ◼ Repair any shrinkage around “peep” © ABB Lummus Global Confidential doors, wall burner tiles with loose fiber or pumpable refractory Refractory System ◼ Typical Problems ◼ Ceramic Fiber will shrink after heating ◼ Problem Areas ◼ Around Peep Doors ◼ Around Wall Burner Tiles ◼ Must pack all gaps with loose fiber or © ABB Lummus Global Confidential inject pumpable insulation ◼ Expansion Joints in Castable (Floor/Arch Areas) Refractory System ◼ Problem Areas ◼ Roof Insulation May Fall out from around the tube penetrations ◼ Wet Insulation will Fail ◼ Repair As Soon As possible ---- before © ABB Lummus Global Confidential heat damage occurs Refractory System ◼ Problem Areas – Cont’d ◼ Radiant Firebox RoofTubes MUST be free to move/expand ◼ Water/Coke from TLE cleaning must not accumulate on top of Radiant Roof. Water will leak in and destroy the ceramic fiber, causing it to fall. Coke on Roof can burn if exposed to radiant heat ◼ Must maintain the integrity of the radiant © ABB Lummus Global Confidential inlet and outlet insulation blankets Refractory System Radiant Coil Inlet Passes – Roof Penetration © ABB Lummus Global Confidential Insulation Must Allow Free Movement of Tubes Refractory System ◼Problem Areas – Cont’d ◼“Housekeeping” ◼Must keep the radiant firebox roof area clean and well maintained. Area around counterweights – no debris © ABB Lummus Global Confidential ◼Roof panels must be sealed, airtight after they have been removed Refractory System Radiant Coil Outlet Passes – Roof Penetration © ABB Lummus Global Confidential Insulation Must Be Kept Sealed to Keep Out Water © ABB Lummus Global Confidential Radiant Section Suspension Radiant Coil ◼ SL-2 Coil – Support System ◼ The outlet tubes are bolted to the TLE, which is a fixed point. ◼ The weight of the coil is supported by the counterweights ◼ Each “piece” can move independently and is supported independently, i.e. © ABB Lummus Global Confidential ◼ Crossover ◼ Inlet manifold/radiant coil Radiant Coil Suspension System ◼ Top Outlet Directly Connected to TLE ◼ Minimizes Residence Time at TLE Inlet ◼ Outlet Pass Simply Supported From Fixed Point TLE ◼ All Thermal Expansion of Outlet Pass Is Vertically Downward ◼ Inlet Passes of Radiant Coil and Crossovers Supported by a Counterweight System ◼ Counterweight System Is Simpler Than Springs and More © ABB Lummus Global Confidential Reliable ◼ Provides for Free Vertical Movement of Coil and Crossovers As Outlet Pass Expands Downward Radiant Coil Suspension ◼ SL-2 Coil © ABB Lummus Global Confidential ◼ Support Counterweight System Causes of Coil Distortion ◼ Process/Operation ◼ Temperature Difference Across Tube Diameter Caused by Asymmetric Firing or Circumferential Variation in Coke Thickness ◼ Mechanical ◼ Application of Compressive Loads or © ABB Lummus Global Confidential Bending Moments to Tubes Bowing of 40 Ft. Long HP-40 Tube O.D. 8 Offset (multiple of O.D.) 7 6 6" O.D. 4" O.D. 3" O.D. 2" O.D. 5 4 3 2 1 © ABB Lummus Global Confidential 0 0 10 20 30 40 50 60 70 80 T (oF) Temperature Difference Across Diameter 90 100 Offset Large Distortions Generally Due to Mechanical Causes ◼ Restraint of Free Vertical Movement of Coil ◼ Bending Moments Applied to Coil © ABB Lummus Global Confidential ◼ ◼ Jamming or Excess Friction at Bottom Guides ◼ Excess Friction or Restraint at Arch Penetrations ◼ Improper Counterweights Supporting Coil And/or Crossover. ◼ Crossover counterwieghts not free to move if cables too short or constrained ◼ Restrained Movement of Counterweights ◼ Insufficient Flexibility in Coil And/or Crossover Design Insufficient Flexibility to Account for Temperature Differences Among Inlet Tubes Radiant Coil Suspension System ◼ Coil Guided at Bottom of Pin and Channel Guides ◼ Maximizes Utilization of Firebox Height ◼ Eliminates Pipe Guides Penetrating Hearth which Can Jam and Cause Bowing ◼ Eliminates Hearth Penetrations and Potential Air Leakage to Firebox ◼ Flexible Fingers Provide for Different © ABB Lummus Global Confidential Thermal Expansion of Adjacent Tubes in Inlet Pass © ABB Lummus Global Confidential Radiant Coil Bottom Guides - Typical © ABB Lummus Global Confidential Burners and Combustion Burners and Combustion ◼ Combination hearth (floor) and Wall Burners ◼ Approximately 85% of heat comes from the hearth burners ◼ Approximately 15% of heat comes from the wall burners ◼ Combustion Air control is Manual ◼ Manual control of hearth burner air © ABB Lummus Global Confidential ◼ Manual control of wall burner air ◼ Initial commissioning and setup of burners is CRITICAL ◼ Proper Burner Maintenance is CRITICAL Burners and Combustion ◼ Basic Problem ◼ Small burner orifices – 1.0 mm or smaller ◼ Easily plugged with line scale or dirt left over from construction ◼ Hearth Burner gas tips are exposed to radiant heat ◼ Cooling is provided by gas flow during operation. Any restriction will cause tip to heat and plug with coke. ◼ Fuel gas will contain “green oil” – heavy polymeric oil produced in the charge gas dryers. ◼ Can cause coke in hearth burner tips © ABB Lummus Global Confidential ◼ Will cause dust/dirt to accumulate in the venturi of the wall burners Excess O2 ◼ Maintain Excess Air at Minimum of 10% (2.0 Vol or Mol% O2) ◼ Sample Oxygen at Heater Arch at Convection Section Inlet ◼ Sample O2 at several Points Along Length of Heater, ◼ Suggest Second Sampling Location at Convection © ABB Lummus Global Confidential Section Outlet to give Quantitative Indication of Air Leakage into Convection Section Hearth Burners Secondary Tip(s) Primary Tip/Pilot © ABB Lummus Global Confidential Air Damper Hearth Burners Typical Wall Temperature Profile from the Burners © ABB Lummus Global Confidential Typically – The Peak Temperature is at Approx. 6-8 M Above Hearth © ABB Lummus Global - 56 Confidential - Section 6.0 Wall Burner Burner Performance Relative Heat Flux Profile 10 9 8 Elevation - Meters 7 6 Test 5 CFD 4 3 © ABB Lummus Global Confidential 2 Velocity vectors show flue gas entrainment 1 0 0.6 0.7 0.8 0.9 1 Firebox Circulation Dead Zone ◼ Flue gas recirculation patterns ◼ Influence of temperature on flue gas flow ◼ Floor burner recirculation affects the entire firebox ◼ Secondary fuel is burned entirely with recirculated flue gas © ABB Lummus Global Confidential ◼ Flue Gas Flow Patterns are not completely uniform - Some areas do not circulate © ABB Lummus Global Confidential Convection Section Coils Convection Section Arrangement Naphtha Feed Preheat BFW Upper Preheat Dil Steam Upper Mix Pht USSH © ABB Lummus Global Confidential LSSH Mix Preheat Crossovers Convection Section Arrangement A-106 B Carb stl Finned SA-106 B Carb stl Finned SA-335 P11 stl Finned © ABB Lummus Global Confidential SA-335 P91 11 Cr stl Finned 304H SS Finned/Bare Fd Preheat BFW USSH LSSH Convection Section ◼ Tubes and Supports Are Subject to External Fouling © ABB Lummus Global Confidential or Damage From Overheating Convection Section ◼ Cleaning ◼ Steam Air Lancing of the External Surfaces © ABB Lummus Global Confidential ◼ Water Washing From Top of Convection Tube Bank Convection Section ◼ Fouling of the Extended Surfaces Also Increases © ABB Lummus Global Confidential the Pressure Drop on the Flue Gas Side Convection Section ◼ Extended Surface Tubes (Finned Tubes) Are © ABB Lummus Global Confidential Subject to External Fouling or Damage From Overheating © ABB Lummus Global Confidential Convection Section Crossover Piping Cross Over Piping ◼ The Cross Over Piping is defined as the pipe that connects the hot mixed feed from the convection section to the radiant coil ◼ Piping is supported independently from the radiant coil ◼ Must be balanced independently from the © ABB Lummus Global Confidential radiant coil and then welded to the balanced radiant coil ◼ Piping is supported by cable hung counterweights Cross Over Piping ◼ The Cross Over Piping must be free to move ◼ Any instrument connections, such as PT’s or TI’s must have room to absorb the movement of the crossover pipes ◼ Counterweight cables must have sufficient © ABB Lummus Global Confidential space in the floor/grating so that they can move over their full travel from cold – hot ◼ Necessary to review the pipe stress calcs to see the predicted movement direction/distances Cross Over Piping ◼ Typically, the inlet piping to a convection service is a fixed point, and the outlet will grow out from the heater. ◼ During initial heatup/startup monitor all pipe movements to determine that the piping is not constrained and is moving according to the design of the supports. ◼ When piping is cold, it should align with the © ABB Lummus Global Confidential cold marker on spring support cans. ◼ When piping is hot, it should align with hot marker on spring support cans. Cross Over Piping Expected Movement Fixed Point © ABB Lummus Global Confidential Must Ensure Free Expansion of Crossover Piping and Counterweights © ABB Lummus Global Confidential TLE’s OLMI TLE © ABB Lummus Global Confidential •Fixed tubesheet shell and tube type •Tubes and tube to tubesheet welds are loaded •Special bore welding used at inlet tubesheet •Tubesheet are flexible •Knuckle radius of outer perimeter of tubesheets allows flexibility © ABB Lummus Global Confidential OLMI TLE OLMI TLE © ABB Lummus Global Confidential It is Extremely Important to Blowdown Each TLE Regularly – According To OLMI’s Instructions Intermittent Blowdown Connection © ABB Lummus Global Confidential OLMI TLE TLE’s TLE Cold Inlet Flange © ABB Lummus Global Confidential Flanges Must Be Left Uninsulated TLE’s ◼ The Primary TLE’s will plug with coke and need to be mechanically cleaned every 3-4 runs ◼ Typically for Naphtha the entire tube will require hydroblasting © ABB Lummus Global Confidential ◼ If at any time TLE pressure drop exceeds approximately 0.4 Bar, the TLE needs cleaning. Do not operate the heater if the pressure drop exceeds 0.5 Bar, or damage to the TLE may occur. TLE’s ◼ High Pressure hydroblasting is used to remove the coke ◼ TLE Cone should not need to be cleaned, © ABB Lummus Global Confidential inspect the refractory and maintain as needed. A TLE cone removal support system is provided © ABB Lummus Global Confidential Draft And Pressure Profile Heater Pressure Profile ◼ At the Outlet of the Stack Flue Gas Pressure Equals Atmospheric Pressure ◼ Atmospheric Pressure Decreases with Elevation ◼ Pressure Inside Firebox Decreases with Elevation but at a Slower Rate Because of Lower Density ◼ By Definition Draft Is the Difference Between Pressure Inside the Heater and Local Atmospheric Pressure Outside the Heater; Negative by Design ◼ Because Both Atmospheric and Internal Pressure Vary, © ABB Lummus Global Confidential Draft Varies With Elevation Pressure Reference Point Fan Exit Fan Inlet Damper Exit Damper Inlet Conv. Section Exit © ABB Lummus Global - 81 Confidential - Section 6.0 Conv. Section Inlet Draft at Top Burner Draft at Hearth Air Leakage ◼ Air Infiltration into the Convection Section ◼ Reduces Efficiency ◼ Loads Induced Draft Fan ◼ Convection module seams should be sealed during construction ◼ Piping penetrations should have a cover/seal that © ABB Lummus Global Confidential is free moving and seals both when the heater is cold and hot – must not bind expansion of the tubes/piping ID Fan ◼ Electric Motor Driven Fan ◼ Typically ball or roller bearings on shaft/overhung impeller – maintain proper lubrication – use high speed lithium grease only. ◼ Check that there is a water drain valve on the fan casing and that it is open (leave it open) ◼ Maintain/Inspect the Fabric Coupling between the Heater and Fan Inlet ◼ Do not run the Fan for long periods at low rates, © ABB Lummus Global Confidential especially if it is vibrating (vibration is a sign of fan surge/stall) ◼ Vibration is common at low rates, especially with cold fluegas ID Fan ◼ ID Fan is provided with a Variable Speed Electric Motor and automatically controlled inlet damper. ◼ Normally use the VSD Motor to Control Pressure ◼ It is critical that the actuator/positioner are correctly calibrated to the actual damper position during commissioning ◼ Bearings in the dampers must be kept lubricated – © ABB Lummus Global Confidential dampers should always be free moving, lubricate any fittings in the actuator shaft assembly as well ◼ Bearings may show wear quickly if the heater pressure controller is tuned incorrectly – damper should move slowly and only when it needs to. © ABB Lummus Global Confidential Transfer Line Valves TLV/Decoke Valves © ABB Lummus Global Confidential ◼ Decoke take Off ◼ Top of transferline in liquid crackers downstream of quench fitting ◼ Bottom or side of transferline in gas crackers or in naphtha crackers downstream of the TLV ◼ Decoke valve mechanically interlocked with TLV to provide overpressure protection ◼ Three valve system TLV/Decoke Valves Double Disc Through Conduit Wedged Gate Valve © ABB Lummus Global Confidential Mechanical Linkage TLV/Decoke Valves © ABB Lummus Global Confidential Double Disc Through Conduit Wedged Gate Valve Body - Blue TLV/Decoke Valves © ABB Lummus Global Confidential Double Disc Through Conduit Wedged Gate Valve Body - Blue Guides - Green Stem - Orange Wedges - Red Ball - Cyan Discs - Purple Seat Rings - Yellow Sleeve - Cyan Bellows - Lt. Blue Carrier - Dark Gray © ABB Lummus Global Confidential TLV/Decoke Valves Open Closed TLV/Decoke Valves Double Disc Through Conduit Wedged Gate Valve © ABB Lummus Global Confidential Mid - Stroke TLV/Decoke Valves • • © ABB Lummus Global Confidential • Permanent & continuous purge steam flow through the valve body must be guaranteed under every process condition. This is of uppermost importance for a long term trouble free valve performance. The purge steam body pressure has to be throttled to and maintained at approx. 0,5 bar above the actual pressure in the connected process lines for the following reasons: - Purge steam flow keeps the body on temperature (reduced potential of condensations as well as solidification of viscous process fluid) - Purge steam avoids particle entry into the valve body and prevents coke build-up on internal parts - Purge steam barrier provides additional safety against leakage of process fluid through the closed valve - Purge steam blows out process particles which possibly entered the body during valve operation Purge steam pressure shall never exceed the design pressure of the body with respect to the differential pressure for actuator sizing. TLV/Decoke Valves Recommended Check Valve Specifications: Edwards Vogt - Piston Check Valve Class 800 equipped with SS spring and Socket Weld type connections Steam purge to small and large decoke valves. Relief Valve Set Pressure 0.5 MPa(g) PDC PDC Setpoint 0.05 MPa(g) Steam Purge Purge Steam M 1” FE Note 1 © ABB Lummus Global Confidential Transferline 1” 1” 600 mm MIN. 2” Clean out connection Recommended Check Valve Specifications: Edwards Vogt - Ball Check Valve Class 800 equipped with SS spring and Socket Weld type connections TLV/Decoke Valves © ABB Lummus Global Confidential Signs of Excessive Force on TLV Body TLV/Decoke Valves © ABB Lummus Global Confidential Piping Does Not Align With Valve Flanges TLV/Decoke Valves © ABB Lummus Global Confidential Piping Does Not Align With Valve Flanges © ABB Lummus Global Confidential
