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Home Forums Coking Design and Reliability Cokedrums, Structure, Inspection Drums COKE DRUM FABRICATION & DELIVERIES RE: COKE DRUM FABRICATION & DELIVERIES


Charles Randall

Ok – I promise this will be my last entry & others can “take up”  this cause if they think it is going do any good …… previously they have not!
This is already giving me “Deja Vu” headache’s because it is SO similar to past dicussions of logic issues with my ex-wife who was often emotionally invested in her view-point ……And I can see fabricators might be coming from that type reference on these issues (Make a Paradigm Shift guys!)!  I do have lot sympathy for new companies like Bill’s Mangiarotti that is just trying to break into an established market and get on the Approved Vendor’s List (similar to everyone trying get that first job that depended on experience that you cannot have until you get that first job….).
But the last set “added comments” to my observations (contrary to guest – well done comments) – puts me in position where I now have to cry Bullshit! Guys –These types of positions are one reasons that EPC & Fabricator’s are seen as part of the problem and not part of the solution around Coke Drum issues. Coke drums are ALWAYS part of process license guarantee – not can be. And If you think companies are spending $100’s million for refinery cokers or $ billion’s for upgrade cokers based on fabricators 18 month, warrantee guarantees for coke drums mechanical designs based on ASTM “pressure vessel codes” instead the process coke drum designs that take into account stress / fatigue impacts and driven by coke licensors process guarantees which depend on operating drums/units at least 5000 cycles over 10-18 years (depending on what real coker cycle time is)…..then your being obtuse. 
I “jacked-up” several of my contacts in areas of Coke License, stress monitoring, Drum inspection and refinery mechanical operations/metallurgy as to why they had not joined in on this blog discussion?  They all said the same thing – it is because they fight the battles they can win & many of EPC contractors and Fabricator companies just won’t listen and won’t change what they do.  So About 5 years ago these groups gave up & started working directly with each other to effect the change in the industry & process after several drum failures (and could be part reason it is so tough to get added on Approved Vendor List ….eh)?
The Pressure Vessel Codes that currently are used by the industries for Coke Drums are completely wrong for this application – the vessels in this category never have the type of Stress and Fatigue Cycles that Batch Operated Coke drums go thru. And because they warm up from ambient to 900F and then quench back from 900F to ambient and become category all by themselves & ….. unfortunately the suppliers seldom care. The Refineries, inspectors, monitors & Licensors have been trying for years to get the ASTM to change these codes for Cokers – if want be part solution start helping that process & not staying with limited guarantees for pressure vessels that seldom see stress.  
Also – to become part solution you (and as many of your shop people as you can force your company pay for) need to sign up for SES Coke Drum Workshop and go “actively” listen to refiners & these other groups issues.  But NOT go so you tell them why their viewpoint is wrong …. (like your trying to do here &) like CBI has done previously when it’s Steel supplier’s metallurgist tried to discount need for fab shop to stress relieve the drum there instead of in the field al-natural. It should noted that one reasons for a big shift towards SHI as drum supplier of choice is because they routinely shop stress relieve drums/welds on all coke drums…. unlike other fabricators where clients must insist and often follow-up with site visits to make sure its done “above PV codes” requirements. Fabricators following just PV codes are usually taking short cuts without even knowing it & introducing “less than stellar results” I talked about last time.
Coke Drums CAN be designed and fabricated to handle the stress cycles but the sad fact is that most are not! During the 80’s and 90’s most Coke drums were only built (or replaced) under pressure vessel codes and as result the majority of them cracked within 4-7 years compared to some drums lasting over 30 years now!  This drove some changes around metallurgy from Carbon Steel to Chrome-Moly drums /liners and then back as cracks happened – then the groups & process mentioned earlier started asserting themselves over the objections of EPC & Fabricators.
Now I am leaving out lot things that make the higher level requirements above codes become only a minimum step and not a targeted step – because the coke units dont get to operate at process designed guarantees of 18-24 hour cycles, usually they are driven as low as 9-14 hours and they dont run on predicted heavy crude’s because the quality continues to drop as both the sulfur increases and Bitumen type crude’s add higher TAN and Naphathneic Acid levels to corrosion problems / issues.
But you get my points – dont worry about these shorter term delivery / getting more drums / making APL list problems. The Financial market, refinery economics, demand and ect will take care of those – worry about the long term problems and what problems your customer has and less about what your perspective on them is – after all fabricators only live with drums for 18-36 months while the customer has to live with them for 15-30 years (if they are lucky) and 4-7 if they are not lucky…..and when they are not it is ~ like being married = when momma isn’t happy then no-one stays happy for long!

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