PDF Publication Title:
Text from PDF Page: 006
SinincetthedenssitityyoffPE((~59..6lblbss//ccubicicffoott))isisonlylyslilgighttlylylolowerrtthan tthattoffffrreshwatterr((~62..3lblbs//cubicicffoott))tthepipipeconttrribibuttessomewhatt 364 Chapter 10 M a r i t n t oe o I wn ws t a a a l r l ar dt di os sn s n n e e t t b b u u o o y y a a n n c c y y . . H H o o w w e e v v e e r r , , t t h h e e m m a a j oj o r r l i l f i f t t f f o o r r c c e e c c o o m m e e s s f f r r o o m m t t h h e e a a i r i r - - ffilileledininnerrvolulumeofftthepipipe..Sinincefforrapipipeoffgivivenouttsididediaiametterr,, tthesizizeoffttheininnerrvolulumeisisdetterrmininedbytthepipipe’s’swallltthicicknes– tthegrreatterrtthetthicicknes,,tthesmallelerrttheininnerrvolulume–andsinincea pipipe’s’sacttuallwallltthicicknescanbeexprresedinintterrmsofftthepipipe’s’s inner volume – and since a pipe’s actual wall thickness can be expressed in terms of diaiametterrrrattioio((DR)),,Equattioion11canberrearrrangedasshownininEquattioion the pipe’s diameter ratio (DR), Equation 1 can be rearranged as shown in Equation 2. 2..Therresultltanttnettbuoyancyfforrcecanbedetterrmininedffrromtthepipipe’s’s The resultant net buoyancy force can be determined from the pipe’s actual outside acttuallouttsididediaiametterr,,ititsDR((orrSDR)),,ttheexttenttttowhicichtthepipipeisis diameter, its DR (or SDR), the extent to which the pipe is filled with air, the density of ffilileledwitithairir,,tthedensitityofftthewatterrininttowhicichtthepipipeisissubmerrged,, the water into which the pipe is submerged, and the densities of the pipe and of the andtthedensititieiesofftthepipipeandofftthelilqiquididininsididetthepipipe:: liquid inside the pipe: (2) ρ 22 WHERE BB F =[0[0..0545D ρ ]]4..24 +11− (1(1−R)) −11 ((Eq..2)) BB 22 cc F Do = external diameter of pipe, in B = buoyant force, lbs/foot of pipe w = density of the water outside the PE pipe, lbs/cu. ft oo ww ww ((DR−11..06)) pp 2..112 ρ ((DR)) Do=extterrnalldiaiametterroffpipipe,,inin ρ ww DR Wherre:: F =buoyanttfforrce,,lblbs//ffoottoffpipipe DR=pipipedimimensioionrrattioio,,dimimensioionleles DR = pipe dimension ratio, dimensionless R ρ R =ffrracttioionoffininnerrpipipevolulumeocupieiedbyairir = fraction of inner pipe volume occupied by air 22 ρ =densitityofftthewatterrouttssididetthePEpipipe,,lblbss//ccu..fftt ww =densitityofftthepipipematterriaial,l,lblbs//cu..fftt.. ρp = density of the pipe matepprial, lbs/ cu. ft. =densitityoffpipipeconttentts,,lblbs//cu..fftt.. ρ c = d e n s i t y o f p i p e c o n t e n t sc , c l b s / c u . f t . The derivation of Equation 2 is presented in Appendix A-1. The reader is advised that Equation 2 does not ThederrivivattioionoffEquattioion2isisprresenttedininAppendixixA--11.. consider lift forces that can result from water currents; refer to Appendix A-2 for further assistance with this topic. AmorresucinincttwayoffexprresiningttheprrinincipipleleembodieiedininEquattioion2isis A more succinct way of expressing the principle embodied in Equation 2 is asffollolows:: as follows: (3) F = W F[“=KW”W] [[““K””]] ((Eq..3)) 55 B DWBB DDW WHERE Wherre:: W = 0..000545D w DDW oo WDW = 0.00545 D20ρw StatSeSdttainttewdoirnidnsw,wtohoerrdrdess,u,tlththaenetrbreussouyulatltnatnftotrbcbueuo(oFy)ainsntetqffouoarrclceteo (t(FhFeBBp))oisitsenetqiqauluatahlletotoretthihceaelpottenttiaiall B buotythaeneotofrorertctiecic(aWllbu)otoiymyaensntatfbfourorcyean((cWy DrDeWd)u)cttitmimonesfsacatobrbu(u“oKoy”y)atnhncactytarrkedsuiunctotioioancncoffauacncttorr((““K””)) DW inntethrhapaitpttetavkoeleusminien,ttodoeagarcececoufuanitrtifininlnlinegrrapnidpipetehevvodoelulnumsmiteie,s,dodfetghgrerepeiepoeofafnadirirtfhfielililninqgugiadandtthe i n s i d d d e e e n t n h s e s i t i p t i e i i ep s e s . o o f f t t h h e e p p i p i p e e a a n n d d t t h h e e l i l q i q u u i d i d i n i n s s i d i d e e t t h h e e p p i p i p e e . . The manner by which the buoyancy reduction factor “K” is affected by a pipe’s DR and the extent to which its inner pipe volume is filled with air, R, is indicated by the calculation results reported in Table 1. The values in this table have been computed based on the following densities: 62.3 lbs/ cu. ft for water both inside and outside the pipe, and 59.6 lbs/cu. ft for the PE pipe material. Using these K-values for approximation of the net buoyant force of a submerged pipeline in which a portion of the line is occupied by air greatly simplifies the calculations involved.PDF Image | Marine Installations PE
PDF Search Title:
Marine Installations PEOriginal File Name Searched:
PE-Marine-Installations.pdfDIY PDF Search: Google It | Yahoo | Bing
Development of a solar powered Electric Ship The Electricship website originally started off as a project to develop a comprehensive renewable, affordable, modular electric ship... More Info
Modular Boat Hull Composite The case for a unsinkable, modular composite hybrid boat hull... More Info
MS Burgenstock Hybrid Electric Catamaran Lake Lucerne Unique shuttle servicing Lucerne to the Burgenstock Resort... More Info
Ground Power Unit GPU Powered by Lithium Ion Batteries The goal of the Ground Power Unit is to provide a readily accessible, modular, ready-to-power solution for remote power... More Info
CONTACT TEL: 608-238-6001 Email: greg@electricship.com (Standard Web Page)