GPA USED PLANTS & EQUIP-2002 Guidelines for Reapplying Used Plants and Equipment.pdf

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1、Guidelines for ReapplyingUsed Plants and EquipmentPrepared for:GPA Technical Section A: Facilities DesignbyMichael W. Conder, P.E.GPA DisclaimerGPA publications necessarily address problems of a general nature and may be used byanyone desiring to do so. Every effort has been made by GPA to assure ac

2、curacy andreliability of the information contained in its publications. With respect to particularcircumstances, local, state, and federal laws and regulations should be reviewed. It is not theintent of GPA to assume the duties of employers, manufacturers, or suppliers to warn andproperly train empl

3、oyees, or others exposed, concerning health and safety risks orprecautions.GPA makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability or responsibility for loss or damage resultingfrom its use or for the violation of any federa

4、l, state, or municipal regulation with which thispublication may conflict, or any infringement of letters of patent regarding apparatus,equipment, or method so covered.“Copyrignt 2002 by Gas Processors Association. All rights reserved. No part of this Reportmay be reproduced without written consent

5、of the Gas Processors Association.”IntroductionReapplying used equipment and/or plant systems has been done successfully in the natural gas processingindustry for many years. It has been proven for all types and sizes of plants. However, until now therehas been little published information on how to

6、 complete a project of this sort successfully.This monograph has been written to help those who may be interested in reapplying used equipmentand/or plants in the gas processing industry. It is the result of many years of experiences of members ofthe Gas Processors Association Technical Section A: F

7、acilities Design, and of their fellow workers.Much of this knowledge has come the hard way: by making mistakes. So I have included many anecdotesto help illustrate the points made in the text: these are called “Cases in Point”. All of these cases haveactually occurred to one or more members of the S

8、ection A committee, or to their fellow workers but, toparaphrase the saying, the names have been deleted to protect the innocent.The title of this monograph is “Guidelines for Reapplying Used Equipment”. The word “Guidelines” hasbeen specifically chosen because that is what they are: guidelines. The

9、y are not rules, regulations, bestpractices, or standards. They are merely recommendations and advice, thing to consider when one isdeveloping or implementing a project that includes used equipment. They are not all inclusive. Indeed,one thing the cases prove is that every project will have some new

10、 and unexpected problem to handle.And as with all advice, the one receiving it must evaluate the advice and decide whether it is worthwhileto follow or mere bunk.This monograph only deals with the unique aspects of used equipment. The plant designer will also needto follow the same installation requ

11、irements and good engineering practices that new equipment requires.The monograph is organized in sections, dealing with an overview of some of the characteristics of aproject that includes used equipment, through the acquisition of the equipment to the refurbishment andinstallation of the equipment

12、.I would like to thank the Gas Processors Association for giving me the opportunity to write thismonograph. I would also like to thank my coworkers and fellow committee members who have passed ontheir fascinating, and occasionally embarrassing, anecdotes of past projects. This monograph would nothav

13、e been possible without access to their experiences.Michael W. Conder, P.E.March, 2002IndexI. IntroductionA. Reasons for ReuseB. LimitationsC. Project RisksD. Typical Project ProcedureII. Selecting a PlantA. Finding and Acquiring the PlantB. Prepurchase Plant Inspection1. On-site Visual2. Functional

14、3. Non-destructive TestingC. Plant Information and PSMD. Purchase AgreementsE. Original vs. Modern CodesIII. Reapplying a PlantA. Process redesignB. Plant Modifications/Combinations1. Process Modifications2. Equipment Modifications3. Assembling New Plants from OldEquipmentIV. Moving a PlantA. Skid M

15、ountedB. Block MountedV. Refurbishing the PlantA. GeneralB. On-site vs. ShopC. Replace vs. RepairD. CleaningE. Component Guidelines1. Piping2. Valves3. Pressure Vessels and Filters4. Towers5. Heat Exchangersa. Shell many others believe that used equipment will cut the cost of a project by 50% or mor

16、e. Althoughthere is a kernel of truth in both of these opinions, the reality is usually somewhere in between.While cost reductions can be significant, they may not be as great as one would first believe. As anexample, consider the installation of a “typical” block-mounted plant. Experience has shown

17、 that theinstalled cost of such a plant is normally 2.5 to 3 times the cost of major equipment; i.e., theequipment cost is only 35-40% of the project cost. If the cost of the refurbished used equipment is 50-75% of the cost of new equipment, then total project costs will be reduced by only 10-20%. S

18、inceskid-mounted plants include most of the piping and instrumentation with the equipment, total projectcost savings can be 15-25% of an equivalent new plant.These project savings are at risk if the used equipment requires extensive refurbishing, or if the needfor refurbishing is not discovered unti

19、l the end of the project. Proper preparation and inspection at thebeginning of the project can protect the savings in capital cost and project duration.Projects that are based on used plants or equipment fall into three categories: complete used process systems, such as skidded plants, with or witho

20、ut process modifications plants which employ only a few used pieces in a mostly new unitGPA Technical Section A Monograph: Guidelines for Reapplying Used Plants and Equipment Final DraftSeptember 20022 plants assembled from many used pieces into a new arrangement, often coming from severaldifferent

21、sourcesEach has its advantages and disadvantages. There often is a trade-off between total cost of the plantand process flexibility. In other words, employing used items in a plant extensively can reduce theoverall project cost but may require some compromises in the overall plant design which could

22、 lead todecreased plant performance (higher operating costs, lower recoveries, etc.). The optimum balancebetween these trade-offs will be a function of many factors, including project life, plant complexity,processing economics, performance specifications, plant location, etc.Rapplying used plants a

23、nd equipment is not always the best path to a successful project. Early in theproject, the project designer must be realistic in evaluating the extra effort of reengineering,inspecting, purchasing, dismantling, refurbishing and moving the used items over the effort requiredto install new items. Many

24、 times there will be no savings in project time or capital cost; in fact, theused plant may have higher project costs than the costs of a new plant. The plant designer should beprepared to change direction if a new plant is warranted.In many cases, project cost savings are not the major consideratio

25、n in a decision to reapply a usedplant. Schedule reduction can often be the overriding factor. Refurbishing a plant rarely takes morethan 6-8 weeks unless extensive modifications or equipment replacements are required, while newplants are rarely available in less than 12-16 weeks. If the plant is th

26、e limiting factor in the projecttimeline, the resulting improvement in project economics from having the plant available earlier canbe many times more than the project cost savings.Case in Point: A company purchased a cryogenic plant that had been built from used equipment.The plant had been difficu

27、lt to operate, due to the lack of proper engineering during design andinstallation. Soon after the purchase, the plant was shut down and the gas diverted to a nearbyplant that had excess capacity.A surge in drilling and gas production soon filled the nearby plant, and new capacity was neededto meet

28、a contractual deadline with the gas producers. The company compared the time and costto build a new plant with higher product recovery against rebuilding the old plant, and decided torebuild the old plant to handle the new gas. The plant was inspected, redesigned, costs wereestimated and the project

29、 was approved.Once the refurbishing began, it was discovered than the plant was in far worse shape thanoriginally expected. Project costs skyrocketed, but the plant was eventually started on time.A review of the project showed that a new plant would have been about the same cost as the finalproject

30、cost but taken about a month longer to complete. The value of the extra product recoverywould have easily offset the revenue received from starting the plant a month earlier. The projectwas deemed as success, though, since it did meet the required deadline.GPA Technical Section A Monograph: Guidelin

31、es for Reapplying Used Plants and Equipment Final DraftSeptember 20023B. LimitationsCompared to building a new plant for a project, reapplying an existing plant can often be difficult andoccasionally impossible. It is rare to find the exact size plant with the best process design for anacceptable pr

32、ice. Many projects based on used plants or equipment are built with compromises inplant performance and/or capacity. Making the right fit can often require flexibility and creativity.Case in Point: A company needed to install a large straight refrigeration processing plant asquickly as possible to e

33、liminate a hydrocarbon dew point problem in its transmission line. After adetailed review of the available plants, and after a couple of inspection trips, no plant was foundwhich had the required capacity. In fact, the closest possibility to meet their needs was to build aplant using two separate tr

34、ains, although the cost of two 50% units exceeded the companysbudget.During the search for the plant, the company found a used gas/gas exchanger, electric compressorand gas chiller from a refrigerated lean oil plant. A search of the market turned up a vessel thatcould be modified as a cold separator

35、 and two air coolers that would be suitable for propanerefrigerant condensing. The company was able to blend these major items with a usedcompressor, new piping and instruments and new equipment and was able to complete the plant inless time than a new plant would have taken.Case in Point: A company

36、 wished to build a fractionator for its produced Y-grade but lacked thebudget to build a new plant. However, it had an old refrigerated lean oil plant that was no longerneeded. The company was able to use two old towers, one new tower, various reboilers, crossexchangers, pumps, vessels, hot oil heat

37、er and air coolers to build a three-tower fractionatingsystem that met their requirements on a significantly lower budget.Some plants and equipment are more suitable for reuse than other plants. For process plants, theeasiest to reuse (and perhaps the most common) are medium-sized skid-mounted liqui

38、ds recoveryunits. Block-mounted liquids recovery plants are also good candidates for reuse. Plants in corrosiveservice, such as amine treaters and sulfur recovery units, are more difficult to reuse and usually costmore to refurbish. Small plants may cost more to purchase and refurbish than new plant

39、s, especially ifthe new plants are “on-the-shelf” plants like field glycol regenerators.Original plant locations and operating conditions are also important parameters. A plant that is stilloperating will probably need less refurbishing than a plant that has been shut down for a period oftime. A pla

40、nt located near the Gulf Coast will probably need more refurbishing than an identical plantin West Texas. Moving a Gulf Coast plant to Wyoming will incur extra cost for winterizing, whilemoving a plant from Wyoming to Louisiana may require extra costs for high performance painting.GPA Technical Sect

41、ion A Monograph: Guidelines for Reapplying Used Plants and Equipment Final DraftSeptember 20024C. Project RisksMost new equipment and plants come with some sort of mechanical and/or process guarantee. Usedequipment comes with no guarantees whatsoever; they are normally purchased on an “as-is, where-

42、is”basis. Therefore, used plants can be riskier than new plants. They can also need a lot moreengineering and check-out work than new plants, due to the need to identify the plants condition anddesign capabilities and to reengineer it into the new process. The added risk has to be managed by: being

43、realistic about cost savings being aware of used plant market conditions verifying the condition of the used plant confirming the design and condition of the plant taking no shortcuts in cleaning or refurbishing the plant, regardless of its history confirming that the plants documentation meets toda

44、ys requirementsD. Typical Project ProcedureNo two projects are developed in the same exact manner. However, projects that employ used plantsor equipment often follow a well-proven path. A generalized description of a typical projectdevelopment is as follows: Identify the process and economic needs f

45、or the project. Review the available internal assets that may fit the project needs. Locate and review the available items on the open market. This is often done through one ormore used equipment brokers. Select one or more candidates for the project for detailed review. This can include a processre

46、design, identifying modifications that may make the used items more suitable for the newuse, or even selecting the items with the lowest price. Inspect the selected item(s) thoroughly, including visual and non-destructive inspections. Verify everything; dont take someones word about the plants condi

47、tion or capabilities. Negotiate a purchase agreement. Acquire the item. Move the item to a location for refurbishing and/or modifying as needed. Move the item to the new project site. Install the item.II. Selecting a PlantA. Finding and Acquiring the PlantUsed plants and equipment usually come from

48、one of three sources: internal ownership, directfrom the current owner and through a used equipment broker. Of these, the internal ownership isusually the preferred source, while getting a plant through the brokers is probably the mostcommon source.GPA Technical Section A Monograph: Guidelines for R

49、eapplying Used Plants and Equipment Final DraftSeptember 20025Using assets already owned by the company building a new project will usually be the best way toreapply the used plant. No cash transaction is required, although an internal charge betweeninternal corporate groups may be required. However, one should account for the market value ofthe used plant by including an opportunity cost in project economics. Also, coordination of theplant “acquisition” and locating critical plant documents and operating histories are