Project Engineering of Process Plants

Project Engineering of Process Plants

(Parte 5 de 10)

fucl for steam gmer;rtiou, engine iuel for el~,ctriral gcnernturs, ;md for produrtim of inert gases fur purging or blanketing srrvices. \\-hen natural gab il to 11e porcl~ased it is important to ohtaiti d;~ta on tllc snpl~ly pressure and an :inalysis i1f the g,zs as 17-rll as a guarantee of its coniposi- tion or the liluits of variati~~n. Xatural gas in solnc areas is \vet or carries a certain nui,)unt of condmsatc. If such is the case. n trill> sl10111d be provided near its entrance to the property. It uiust he decided and clearly pointed out in thc mntract for supply. rvl~icli party shall furnisll the trap and ~vlierc the responsibility for drainage of the trap dl lie, i.c.. ~vith tlir rupplicr or. tlie ~IIITC~I~SP~, \Vhilc rrrtain of the liquid tuatcrials n-ill immediately ev;rporatc upon dischargr, other coti~poncnts ~uny re111aiu iu a liquid state producing ;r l~azard. In conge-tcd iudustrial arew the ilrninagc oi trapped r,indcnsate from natural gas can hecome a i,onsirler- able prohlem. LTnless there r~dl he some process use of these liquids it is hrttcr to insist on a dry gas, furnislicd at a certain prrssurc at the user'; meter.

Tl~c purcliaser lnr~st also ascertain precisely where tllc natural gas pipeline ~iil mtrr thr property and decide which party shall supply the turter, the primary device, thc meter house, valving arrangetnent, and tlie pipiug acwssories. The ahuw suggestions are for supply services in the order oi niillions of cul~ir feet. They are not of itnlmrtnnce for wuall installations ~vith service connections perhaps of 3"-pipe aim or less.

Ho~T-ever, it sliould always be clearly understood which party supplier and installs the equipn~cnt.

\Then the final ci~ntrart is entered into with the supplier a drawing should be prepared locating the cmnccting point of tile owner's piping and showing the type flange, valve, joint, etc. to which plant piping will he connected. Tlicre data should be given the l~urchaser by the supplier.

Natural gas supplicd by pipeline ~vill not ordinarily require auy aux-

Preliminary Dato for Construction Projects 3 1 iliary pressure vessel or capacity tank since the system ~hould provide tlie required capacity. Pressures above 30 to 40 psig for plant fuel syp- tenis are unnecessary. Csually gas supply pipeline prrssurcs arc much ahol-e this rang?. Ordinarily the prohlcui is more one of reduring pipeline prc.;.ttres ti] range.; suitable for plant services. For this reason thi, clue.- tion of supply pressure should he dieruseed as early as possible. If the gas is to he used primarily ior fuel, a slipply line pressure range frmu 50 to 75 psig should be sufficient ti1 allow for plant surges ~vith adequate i~pstrcalti pressure for satisf:rctory control and capacity in tlw l~lant fuel systeni, Pressures at thc point of usage are ordinarily in tlic range of

20 to 30 psig, and ;ire lo~~-er for hurncr headers. Fiiel oils arc usunlly drlirered by railroad tank car or uiotor tank trurk. Facilities for storage of the liquid fuel niurt be providctl. l:su>rIl>- heating iurtst he provided for unloading. Tliis is more fully disrlissctl in Chapter 21. In the preliminary survey, thought should be givcn to proper location of railroad or truck unli~a~ling pint so that tlie initial plmt arraugrnicnt stluli(.s vill inrhldc this facility.

IiqlieJied petvoieii~~i yrrses or gases held in a liquid stnte arc t~c~oming an iml~ortant sourrc of foe1 for donic.stic llcating in some arras, Iioi\cv~.r.

tlicir. usc as indu.;trial furls is still souicwl~at limited. If the p1;tnt is small, this type fucl may he used to an arlwntage for i.datctl huililing hating.

Coal is not ordinarily used as a plant fuel fur tl~c process plant : how rrer, coal may 11e used ns a powr-generating fuel if the projcct is located in a r.oal producing area 01. if other iucls pr11vc uncconoulical. Neressary facilities ~vould )Jc require<l f(1r unloading. storage, and l~at~lling. h nuuilwr oi solid fuels other tlian coal exist; liowever, tl~rir use ~vuuld proh:il~ly rcquirc fiiditi~s siiuilar to that for coal handling.

Plnnt imstes are oftell an ilnpi1rtaut swrcr of fnrl. Their availnhiliiy. of cuursc, dcpcn~ls upon the 1,rocess. If plant ~uay he hrned as iuel, the prohlmm of waste disposal may he airnplified. Plant wnstc.; tl~itt arc to t~e intcrtuittent,ly ~lsed as fuel lllay 1)r0dwc a storirgc proI)1?1u.

Product and Raw Material Transportalion and Sforage

Thr pr~~li~uinary data roncerning plant terrain iuay 1r:rvr ronsiclcral~lc eff'ect on tllc 111c;ltion of w(,h iacilitiw ns ailr road unloa(ling and loading points, and packaging and storage facilities. C:rrtain plant. locnt~d on sIq>iug site haw the liquid pr~lrluet sturagc :~rriingc~l so that ;ill lilading is hy gravity. The location of st,,ragr puints for hazarrlous prwlurtr tilust, Ile rarefully (,ousi(lrred since in order Lu mc~t s;tfct:- r~y~tirrtnerrts :tdd- tional :rrre;lgi, nray be rerluircd It is vcry import;lnt to dcterniiuc the dcgrw oi intcrpl:mt tran?lwrt:i- tion :~nd the storage ~cquireulents beeituse uf their effect on plant nower rc(lr~ireliietits.

32 Project Engineering of Process Plants

Ran. r~~nterials so~iietinies enter plant;. and prodncts Icavc the ~rl:irit hy pipeline. TVherever any piping enters or learrs the plant the cxact pints should he determined a;. early as possible si1 that interference ~r-itll {plant f:~cilitics can be ax-aided.

Procurement Data Prelilninary data :~ffectlng prorurcnlrnt arc:

1. Earlicat date xlren inaterials rliay hc rrwivcil at jdliite. 2. Rwic nl;1terials r~f mn.4ruction :rv;~iI;il~lc in arc>.

3. Connecting r;lilru;i~is and nearwt sn-itch pi,int, councrting in scrvi11n motor truck lines.

4. Slain iligil\r-ny locatime. 5. 1,ocatioil of ncnr<,fr rnt:lrol111litan :irc:~

6. Types of industrial equipnlent u-.e;~hle in l~lant crr~,tion :~ruilahlc in tile imnlediate nrca.

7. Types of industrial drops in the immediate area suitable for repair ur maintenance or 1,arts snl~ply f,~r construction ~~pipuient.

8. Storage space and itorage area fur plant eqriipcnt and con~trw- timi material.

Pr~~cureluent, as diicussed in 9, is intimately related to jirojcct xlleduliug and planning (Chapter 7). Tllc procurement org:illiaation will be rrlort concerned with plant equipn~cnt and construction material transportation. The nietllotls of tmnapurtation, tin~e required, ireiglii rates, constru~tion lunterinl, storage facilities (at the jobsite), field fub- rir;rtioii certain parts of the equipmtmt, and delirery data all affect ~xwurement. Transportation and jol~site storage lmst seriously affect prelinlinary procurcmerrt planning or sclleduling.

Tlir most vital question in procurenlcnt is ah-nys iklirery or deliver? dates. A 11rojcot at a reiuote locntion with a possible tmnsportation tinic of mie ulor~tli \,-ill require all scheduling to iuclude t11k trawl tiluc. Arnil- nhility of con11non materials in the :rrr3;t uf construction tlrgethcr wit11 11rice data rnust he ascertxinetl. Price differentials may ~varrant tlrc pro- curing 11f a large pcrrmtage of materials locxly and thus jlistify a lo(':l procurenlcut ol~emtion. Certain materials such as ready-illisid cr~ncrctv or tl~e nratcrinls required for concretc art. aln-ays l,urelln-id locally on ~louicsti~. ~wojcctr. Sourws of supply ;tnd )".ices for tl~ear ~lr;itrri:l- illit, lw :iscc~~~t:ri~~wl :ls :I 1:~rt of l,rrlin~ir~::ry ~u],vvy <liit:~. 1.uvtil .-:~ler t:~sm uluy atiect price and, tl~ereiurr, nlust be cunsidered ill t11v surv~~y.

Construction Data

All collt;trur.tion pllase> are rtfferttd lly locill wm,litii,w sil~c tlw con- struction orgn~iisation ulrrst beco~ne liiirt of the locale for the x11ole

Preliminary Data for Construction Projects 3 lierioil of crcrtiulr. Tlw iollon.iug il;ltn IUII\~ IE IICCUIIIIII:I~(YI :IS IYLI.I~ possible.

Labor o. Awn I\-RP(, rates, trade union rontrarts in forw and ~spirntirm

,I:~tw. :IIUI :~v:iilxl~iliry of lo1,:1 ~killml ~,r:~ftwren Tr:~ilc u~iion r,lm,wltnlii~n: nanlr-.. ;i~idrc.s~s of all 11c:il or arcn ~lriioli brwinc.s :tgmts.

r. Otliw project.: planned in area nrld times of peak erup1<1ymrnt.

(1. I-niou permit.-if ~,onstruction persnnncl arc to be lnmugl~t into :trr:\. ~ruiiln )remits rll~lit I)? ~htai~lerl for tllcil. work 11y ngrce1111wt I 'I~I(...,.

::re usunlly nwrr ~:~~mpletely satisfied but sliould be attemptcd~ c. .lr:<ilability of personnel hou,qing-this will he r.?olscd if joh is near a large nwtr~~politnn area. f. Food and recreation facilities available.

g. .tIcilical facilities and special cliniat~c sondition~ 1-llich n1:ly affrct persnnnc,l (most illqjul.tant on foreign project ~ork) It. ;\rca practices-these qur.stim; may nevrr he rolnplrt~ly :~nsxcred since lal~ur practices vary condcrahly. See Cliapter 25. Transportation rrquircd by certain liersonnel-some crafts requirc that transportation be furnisllcd or require an allnwinee inr trarel time ~onle~~llat similar to portal-to-portal lmy.

j. Ci~nstruction pcrs(1nnc1 parking facilities-if erection is to take place n-ithin an ol~crating plant nud constructi~~n employers muat lcaw their ow transpilrtation at the plant gat?, it is someti~nrs necessary to rea,,li

;in :tgrcmunt 1%-it11 ihc ovncr on prking facilities. The rpwtion nray souictirr:es be resdrcd by pn~viding a parking area for construction per- sonutal witl~in the plant. These points must be completely underito~l,l ~rcvioilr to start of work.

k. ('haugc aud sanitary f:rcilitics for construction prrsonncl-it is he- mining colnmon 1mcticc for rmitructim pers,mnr.l to haw sllecific spnc~, :~llotti.~l for tllcm to change elotlling. This may require constructiorl of ;l ttwl~urary building. F::nitary faci1itit.s of course innst 11c proviile~l cnrly in rct If plant farilitit.~ exist, the offlier sliould nralie imilities av:iilable.

1. C,~ustruction personnel identification-on rertain work, pliotogrnpili rind finger-l~rillts may be re([uired. Badges arc usually required. JVllen work i. to he ilow in all existing pl;tnt, a11 ovner'a requirements must, i~c detennine~l.

nl. Location of construction material and plant material and equip- rwnt storage areil-the location often seriously afi'rcts jurisdictional

~jroblems ill unloading. transporting, and the handling of materials. Tlic dt,ction uf the storage area, tlleref~~ri,, aside fro111 the best location for

34 Project Engineering of Process Plants

Construction Interference

Tlirse questions arc not usually as iniport:rnt for a complete prl~jert as for \\-,I'~ \vitiiin an ol~ernting plant. C)~KHIIE.ID OR VSDER(:HOISD ELECTRICAL ~'OS'ER LISES. Location, height ahovt! ground, depth lielow ground, voltages, source of power, area sup- plied, uwier or opwat~~r, nearest srrit~,lipoint for q~cnirig circuit ~iud he deternlineii. If guy derrick is used, ~vill guys clear cal~les? Location of dea~l~nen.


size, et~,. Existing 11iping in tlie operating plant is often a sourre of con- sillerablc extra cost to tlie cmstructor of the nen- facilities. ~~~111y 11hllt.~

(lu not IIRV~, exact or reliallle rerurdt; of the locntious of underground lines. Tlie resl~onsibility for removal of such lines should he establialied.

PLAST HAZARDS. In many operating plants nliere work is being per- f~~nnc~l obnoxious or llazardous vapors or funies may be relrased In smne cases work may I~ con~pletcly stopped until the condition is cleared.

Tlie r1~s11onsihilit,~ for costs of unprc~ductive labor during such periods shoul(l be understood. Often serious restrictions exist on fla~nc cutting or n-elding or the use of any open fire on tile premises. It niust t~e deter- niined if any su~,l~ rrstrictions trill be in force. In many hy~lrmarl~c~~i psoceljuing pl:ints and other plants processing hazardous n~aterials all niatcl~cs and pocket lighters must 11e left at tlie plnut gate. Smoking arras niay 11e ~lesignatetl or snoking may hr permittril in runstrurtior~ ~~ersmnicl cliangc liouses. K~cmvrr~; .ANII H.~DLISG OF PIA~ EQUIPMENT. If the \wrk is ill an ol~erntirig plant, tlic owner niay require rert,airl periuita or receiving pro- cedures for material or equiplent delivered rail or truck. Permits niay be required for trucks or cars leaving tlie plant. If all materials are received by the owner, the responsibility for the diipnient, proper accounting, Iiandling, and delivery at the construction site 111ust he deter- mined and clearly understood.

KAIL~AY ASD HI,;H~AY CONSECTIOSS. Exact loeati~lls shouki be determined for p~~ssihle personnel transportation use. The handling of plant and construction materials is greatly simplified by laying a spur railroad track directly into the plant frum the ncarest railroad.

Preliminary Data for Construction Projects 35

Tlie data ili<cussed ahovc are re(~uirc~l as essential preliniinar>- data for any proiert. ('on~idcrahlc additional preliminary data aud decisions ;ire rcquircri for foreign jobs.


Tl~r crrction of plantu in foreign countrirs. diere most of the equip- ment ur ni:rterial n-ill 1x2 rnnnufi~~~tured in the Irnited State?. require? certain overall per~liits or licenses in order to export the various item from tlw T~-niteii lit:it?s zn(l wuiilly import perniits or licenses in nrrler to move the equipment inti tlie rountry ~vliere the plant is to be erected If tlic countr?. is l:rnriln~~kccl ;~nd sl~ipnimt; riiurt move through an adjacent, rountr)-, crrtain ]lcrniits for in-tran~it sliipn~ents will he requirrd

A nunil~cr of niatcrials have heen classified by I1.S. (:ovcmnient;d ;~gcmcie~ as critical to the national economy. Explicit permits niust be ubtaincd to move these n~atcrials out of the U.S..4. Tlie destination and uzr of s~icl~ n~atcrials nffcct the granting of exl~ort pcruiit;. (:11n111lctt! lists of all critical materials: tlie applicable rcstrictims on destinatiou and explanations of the ncecssary procctiurcs are available from the U.S. Government Printing Ofice.

An :~pl~lieation to the 1J.S. Government for an expmt license niust ~~ljually be accompanied hy a complete listing uf all materials aud equip-

~rlerit c,,~nponmts usrd in such equil~mcnt, together ~~it11 wight or v1111uue (as required] and dollar valuc for each item. A numericnl and alpha- hetical designation has been rleveloped fur mrious items. ~vliich designa- tion must he uwl in l~rep~ring the lists. The d~ipping dates by yearly quarters must also be included. I,ater, as shipnicuts proceed tlie specific items must again be listed for each shipment anti checked off the rn:ister list. The preparation of the detailed lists is ro~newliat simplified hy the in- tent of the governmental control, which is more con~wmed r7-it11 runxinunns than ~ith precise or exact evaluations. Care must he taken, ho\wver, to account accurately for items as they are sl~ippcd. Since export license restrictiom change frequently, it is mandatory that each issue of all ap- plicahle govcrnmcntal publications offered by the various agencies be c:lrefully slutlied.

The data necessary to meet the cxpurt license requirements 1\41 only t,ent:itirely permit sl~ipnient. All itenis shipped niust be arcomp:rnic(l in dctnil by the standard export documentation to meet 1-3 custonis ant! sllipping rerpiretuents. l\Iwemcnt of shipments: to dr~ckside. Ti-arr- housing, lighterage, and handling and preparation of hipping documents

(Parte 5 de 10)