Category Archives for Inspection & Maintenance

Mechanical Tube Decoking Typical Procedure

1. For protection of personnel and equipment, cool tubes to 300°F or less before beginning work. 2. Erect scaffolding, open header doors, loosen holding member screws, remove and segregate holding members and plugs. Send components to shop for reconditioning as … Continue reading

18. May 2018 by sam
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Mechanical Tube Decoking

Mechanical decoking, also known as reaming or “turbining,” was once the standard method. It is seldom used now because of its slowness and high cost. Advantages and Disadvantages The advantage of mechanical decoking is that it will work when nothing … Continue reading

18. May 2018 by sam
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On-Line Steam Spalling Typical Procedure

Make provision to record process conditions, including skin temperatures, at 30-minute intervals during the procedure. (See step 16.) 1. Adjust the steam or steam condensate rate in the pass to be spalled to 10 lb/sec/ft2. 2. Lower the pass outlet … Continue reading

18. May 2018 by sam
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On-Line Steam Spalling

This method is used for spalling one pass (at a time) of a delayed coker heater without removing the heater from service. Hydrocarbon flow is removed from the pass being spalled, the flow of steam to that pass is increased, … Continue reading

18. May 2018 by sam
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Sandjet Tube Decoking

This technique is employed by Union Carbide Industrial Services Company (UCISCO) under contract. UCISCO has offices near major refining centers. Steel shot, occasionally crushed flint, is blown through heater tubes by nitrogen carrier gas, physically chipping and scouring coke from … Continue reading

18. May 2018 by sam
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Steam-Air Tube Decoking Typical Procedure

Procedures vary in detail from unit to unit. The following procedure is “generic”. Alternatives are discussed as appropriate. The various safety checks involved in any firing of the heater are not detailed here; see Fired Heater Operations Guide for that … Continue reading

18. May 2018 by sam
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Steam-Air Tube Decoking Special Equipment Required

Much of the decoking equipment is not used between decokings; it should be carefully checked before each use. • A temporary manifold may be used for measurement, control, and mixing of air and steam to individual heater passes. Alternatively, if … Continue reading

18. May 2018 by sam
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Steam-Air Tube Decoking Advantages and Disadvantages

The most important advantage of steam-air decoking is that it takes less time than mechanical decoking and eliminates the need for plug headers, which have leakage problems and a maintenance requirement. A further advantage is that the decoking technique is … Continue reading

18. May 2018 by sam
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Steam-Air Tube Decoking

This is the method most often used. It consists of the spalling step and the cokeburning step. In the spalling step, the tubes are heated, steam is passed through them, and as much of the coke as possible is broken … Continue reading

18. May 2018 by sam
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Smoke Bomb Air Leakage Testing

The following is extracted from a Richmond Refinery Engineering Guideline included in Appendix E. Smoke testing should be performed at the beginning of a turnaround before the furnace has been opened. This will allow time to repair identified leakage during … Continue reading

18. May 2018 by sam
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