Level Measurement ISA

Mark Murphy, PE , Standards Certification Education & Trainin Publishing Conferences & Exhibits

.

-

• • •

•

– Vessel Vess el Nozzle Orie Orien ntat atio ion n – , P roc ocess ess Con ond dit itio ion ns - Tem emp per erat atu ure, Pr P ressur essure, e, Densit Density y, Viscositt , Con Viscosi Cond duct ctiv ive, e, Turbule len nce ce,, Foa Foam m, Va or oriza izattio ion n Occur at the Surface, Sour or Corrosive Service Measur Mea surem emen entt Ran ang ge

• Measur Measurem emen entt Type – Con onttin inu uou ous s (T (Tran ansm smit ittter er), ), P oin ointt (Switch), Local (Gauge) • Con onttact or Non-Con Non-Conttact Measur Measurem emen entt

2

2#

– Based Based on th the e Measur sure ement of Hydros Hydrostatic tatic (D (Down ownward) ward) Force of the t he Liquid Liqu id Hea Head – Level = Press Pressur ure e = h*sg – Calibr libra atio tion n in inches in ches of H 2O

• Heig Heigh ht Met Meter ers s – B as ed o n t h e Id en t i f i c at i o n o f t h e Su r f ac e o f t h e L i u i d – Ca Cali librati bration on in i n inch in che es, feet, feet, %

3

3#

TYPICAL VESSEL

      E       L       D       D       I       R       B

4#

Levell Ins Leve Instru trumenta mentati tion on  –

• An Inst Instrrum umen entt S tan andp dpip ipe e • Allows for Multiple Multiple Inst Instru rum ment ents s to be Connect onnected ed to to the the esse e e um er o ozz e onnec ons on e Vessel Remains Two • without Removing the Vessel from Service • Brid idle le Con Conne nect ction ion Rat atin ings gs and Mat Mater erial ial Sho Shoul uld d Match Match • S ho houl uld d be be Pr P rov ovid ided ed wit with h Both Both Vent an and d Drain Drain Connections • Typica icall Brid Bridle Pip P ipe e Size Size is 2” 2” or 3”

5

5#

Levell Ins Leve Instru trumenta mentati tion on  –

• An Inst Instru rum ment S tandp andpipe ipe which which is Open Open at the Bottom Bottom and an d is Drill Drilled ed wit ith h Ven Ventt Hole Holes s alon alon the Len th of the Standpipe • F lang langed ed on Top of S tand andpip pipe e wher where e Lev Level el Inst Instru rum ment • S ho houl uld d Allow for S pa pace ce bet between Bot Botttom of Vessel Vessel and and ” • P rov rovides ides Add Addit itional ional Prot P rotect ection ion for for Level Instru Instrum ment entat ation ion • R ed edu uce ces s E ffec ectts of P roc ocess ess Turbule len nce F oa oam min • Typica icall Pip P ipe e Size Size is is 2” to 4” 4”

6

6#

Levell Ins Leve Instru trumenta mentati tion on  –

• Metal Metal Con Conttain ainer er used Eit Eith her to: – To Kee Keep p th the Sea S eall Flu F luid id in in th the Ref Refer eren ence ce Legs from from Boilin Boiling g Away in Hot Applications (Steam Drums) – Allo Allow w Ma Main intten ena ance to to Fil F illl the Impulse Lines with Seal Fluid or Act as a Reservoir to Keep the Impulse Lines

7

7#

Levell Ins Leve Instru trumenta mentati tion on  –

• Mec Mechanical De Device Used Used to Exa Exactl S ace Vesse Vessell, Bri Bridle or Level Gauge Nozzle Connections when Nozzles are Welded in Place

8

8#

Levell Ins Leve Instru trumenta mentatio tion n  –

• • • • • • • •

Guid ide ed Wav Wave Radar adar Diff Differen erenttial ial P ressure essure Flo Float / Dis lace Ultr Ultrason sonic Capacit citance Nuc Nuclear Oth Other

9

9#

Levell Ins Leve Instru trumenta mentati tion on

• To Obt Obtain ain a Reliab Reliable le and and Inexpe Inexpen nsive Indicat Indication ion of of Liqu Liquid id Lev evel el in a Vessel Vessel Considerations • The Visible Lengt Length Sho hould uld Cov over er the F ul ulll Operat Operatin ing g Range of Interest Including any Other Level Instrumentation on the Vessel • If More More th than One Gau Gaug ge is Req equ uir ired ed,, th the Gau Gaug ges Mu Must ver ap ac e

10

10#

Levell Ins Leve Instru trumenta mentati tion on

• Tu Tub bular – Tran ansp spar aren entt – • Magn Magnet etical ically ly Cou oup pled

11

11#

Levell Ins Leve Instru trumenta mentati tion on

• Glass Tub ube e wit with h Opt ption ion of Gra radu duat ation ions s • Not P op opu ular fo forr P roce ocess ss Ap Applica licattion ions s • Typically Used for for Calib Calibra ratting Met Meter ering ing

12

12#

Levell Ins Leve Instru trumenta mentati tion on

• • • • •

Metal Cham Metal amb ber (1 &2) Gask Ga ske et (5) Gla Gl ass (3 (3) Cush Cu shiion (4)

Gauge Limitations: • ery g or er ery ow empera ures • P oor Design Wit With h Mult Multip iple le Gauges Gauges May Lim imit it Lev evel el Visibility • Gaug Gauge e Conn Connec ecttio ion n P lu lug ggin ing g • Glass Bec Becom omin ing g Et Etch ched ed or Disco Discolo lorred

13

13#

Levell Ins Leve Instru trumenta mentati tion on

• Gla lass ss Sec ecttio ion ns on Opp Opposi ositte Sid Sides es of the Chamber • View the Liqu iquid id Level thr throug ough h the Gauge • Used on Inter erfa face ce Applica Applicattion ions s • Illum Illumin inat ator ors s Can C an be Used Used to of the Gauge

14#

Levell Ins Leve Instru trumenta mentati tion on

• Sin ing gle Glass Sec S ecttio ion n wit ith h P rism isms s Cut in the Glass on the Process e • Lig igh ht Strik ikin ing g th the Vapor Vapor Ph P hase is Appears Silvery White • Lig igh ht Strik ikin ing g th the Liq Liqu uid P hase is e ra rac e n o e qu w c App ppear ears s Black • , , Noncorros Noncorr osive ive Liqu Liquids ids

15

15#

Levell Ins Leve Instru trumenta mentati tion on

Accessories • Illumin Illuminat ator ors s Can C an be Used Used to Diffuse Light Evenly on the Back of the Gauge  They Ca  The Can n Be P rovided With A Frost Extension

16#

Levell Ins Leve Instru trumenta mentati tion on

• Con onsis sistts of a Non-Magn Non-Magnet etic ic Ch Cham amb ber er,, Inter Int ern nal Floa Floatt wit ith h Ma net an and d BiColored Indicator Wafers

17

17#

Levell Ins Leve Instru trumenta mentati tion on

• The Visible Len eng gth Shou ould ld Cov over er the Fu F ull Operating Range of Interest Including any t er eve nst strrumentat on on t e esse • If More More th than One Gau Gaug ge is Req equ uir ired ed,, th the • Lev evel el Ch Cham amb ber Need Needs s to be Installe Installed d Vertically Level to Reduce any Possible r cto ton n w t t e oat • Req equ uir ire e J ig Set Con onn nec ecttio ion ns

18

18#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Long Long Visi Visib ble Len Leng gths • • Adap Adapttab able le to to Variat Variation ions s in Flu Fluid id Den Densit sities ies • Limitations • Affe Affect cted ed by ch chan ang ges in flu fluid id den ensit sity y • Coat oatin ing g med media ia may may seiz seize e mov moving ing pa part rts s • Ov Over er P ressu essurrin ing g ca can n Im Imp plo lod de Flo Float at • Lon ong g ran rang ges may may re req quir uire e addit addition ional al supp suppor ortt 19

19#

Levell Ins Leve Instru trumenta mentati tion on

O eratin Ph Phiiloso h • Me Mea asu surres H drost sta atic He Head of Li uid in a Vesse Vessell – Liqu iquid id Height Height Mult Multiplied iplied by a Density Density

20

20#

Levell Ins Leve Instru trumenta mentati tion on

Considerations • Vess Vessel el Shap ape e has has no no Imp Impact • E ase of Inst Installa allattion an and d Isolat solation ion – Ine nex xpe pen nsive an and d Most Wid Widely ely Used

• Var ariat iation ion in F lu luid id Den Densit sity y Sho hould uld be Che hecke cked d – Chan hanges ges wit with h Tem emper perat atur ure e and and Com omposition position

• Mount Mounting ing at the Cent Centerlin erline e of Bottom Bottom Noz Nozzle zle or Below

21

21#

Levell Ins Leve Instru trumenta mentati tion on

Diaphragm Seals • • Not S uscep scepttib ible le to to Plu P lug ggin ing g or F ree eezing zing • • May Induce Induce Tempe Temperrat atur ure e Err E rror ors s • Add dded ed Respon esponse se Tim Time e wit with h Lon onge gerr Cap apillar illaries ies • S mall Sp Span ans s Can be be Diffi Difficu cult lt to Measure Measure

22

22#

Levell Ins Leve Instru trumenta mentati tion on

 Att m o s h er  A erii c Ves Vess s el els s

• Onl Only Hi Hig gh P ressu ssurre Side Con Conn nected to Ve Vess sse el • Zero Suppressi ssio on (If Mo Mou unted Be Bellow Low Lowe er Tap Tap)) ose

es s e s w

o n - o n en s a e

as

• • Lo Low w P ress ssu ure Si Sid de is not F illed (Dry leg) •

23

23#

Levell Ins Leve Instru trumenta mentati tion on

Non-Condensable Gas •

Botth Hi Bo Hig gh and Lo Low w P ress ssu ure Sides Con Conn nected to Ve Vess sse el

•

F ill F luid is Ty Typ pically Gl Gly ycerin / Gl Gly ycol Sometime even the Process Zero E levation (Due to F illed Lo Low w P ress ssu ure Side)

•

24

24#

Level Ins Level Instru trumenta mentatio tion n y p es – er en a r es s u r e Differren Diffe enttial Pr P ress essu ure Calcu Calculat lation ion – P ress essu urized Ves Vessel sel With With ea e egs

HLL HL L

S

NLL Y3 LL L

Y1

Y2 H

LT

L 25#

Levell Ins Leve Instru trumenta mentati tion on

Bubbler • When When Air P ressu essurre E nter ers s a Dip Dip P ip ipe e with wit h a Press P ressure ure Greater Than the the Hydros Hydr osttat atic ic Head Head of the the Proces P rocess s , Bott ottom om of the the Dip Pipe P ipe • As th the Liqui Liquid d Lev Level el Change Changes, s, th the Air Changes • Con onsist sists s of P ressu essurre Reg egu ula lattor or,, Rota Rot ameter and P ress ssu ure Ga Gau u e Along with a Stilling Well

26

26#

Leve Levell Inst Instrum rume entation Types Types – Bubbler  Bub bler 

6 5

3 IAS

1

4

2 5

NOTE A STILLING WELL A. FLANGE BOLTS & GASKET BY P IPING. B. TUBING SHALL TERMINATE TER MINATE 1/2" 1/2" FROM FR OM BOTTOM OF STILLING WELL WELL MINIMUM. MINIMUM. OTHER DIMENSIONS DIMENSIONS MAY BE USE D WHEN WHEN REQUIRED. RE QUIRED. 1 2 3 4 5 6

MALE TUBE T UBE CONN 316SS, 316SS, TXMPT  TEE ALL TUBE 316SS, TXTXT TXTXT MALE TUBE T UBE CONN 316SS, 316SS, TXMPT MALE THERMOCOUPLE CONN 316SS  TUBING  TUBING SMLS 31 316SS 0.0 0.049 WALL A213 A213 ROTAMETER ROTAME TER 6.0 6.0 SCFH SCF H 1 1/2 1/2"" SCALE

1 1/2"T X 1/2"P 1 1/2"T 1 1/2"T x 1/4"P 1 1/2" 20' 1/2" 1 1/4" 27

27#

Levell IIns Leve nstru trumenta mentatio tion n  – – • When When a Body Body is Im Immer ersed sed in a Flu F luid id it Loses Weight Equal to That of the Fluid Displaced – Archimedes Law • By Detect Detection ion of of the the Appar Apparen entt Weig Weight ht of the the Immersed Displacer, a Level Measurement

28

28#

Levell IIns Leve nstru trumenta mentatio tion n  – ransm e

• • • • • • •

E xternal Cag Cage e Dis lace Ran Ra nge Sp Sprring Linkage Torrque Tu To Tub be Tra Tr ansm smiitter er ca orce ovemen of Displacer and Rod is Converted to Angular Rotation of Torque Tube

 Tor  Torque Tub Tube

Linkage

Range S rin

Displacer

External Cage

29

29#

Levell IIns Leve nstru trumenta mentatio tion n  –  Tor ue Tu  Tor Tub be Dis lacers Co Con nsi sid derations • Typical Measur Measurin ing g Ran ang ge is 14 14” to 72 72” • Mo Mou untin Or Oriientation for To Torr ue Tu Tub be Ar Arm m • F luid Densi sitty • Ven Ventt an and d Dr Drai ain n Conn Connec ecttio ion ns • Require J ig S et Connections

30

30#

Levell IIns Leve nstru trumenta mentatio tion n  –

• A Measur Measure e of a Mater Material’ ial’s s Abilit Ability y to to Con Cond duct E lect lectrricit icity y

31

31#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Based on Tim ime e Dom Domain ain Ref eflect lectom omet etrry (TDR (TDR)) • a Guide • Wh Whe en the P ulse Rea each che es a Surfac ace e that has a Hi her Dielectric than the Vapor Space it is Travelling in, then the Pulse is Reflected • The Time Time Differe Difference nce bet betw ween the the Transm Transmit ittted and and Reflect eflected ed Pulse P ulse is Conv onvert erted ed int into a Dis Distance from from

32

32#

Levell IIns Leve nstru trumenta mentatio tion n  –

• • • • •

Coaxial Coa Rigiid Tw Rig Twiin Le Lea ad F lexible Tw Twiin Le Lea ad Rigid Single Le Lea ad F lexible Sing Single Lea Lead

• E ach Guid ide e Type Type has has a Maxim Maximu um Measur Measurin ing g Ran ang ge and Minimum Dielectric Constant

33

33#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Dielect Dielectri ric c Con Const stan antts betw between 1.4 an and d 10 100 • The Higher Higher the Dielect Dielectric ric Const Constant ant the Great reater er the Refl eflect ected ed u se • Tran Transit sitio ion n Zon Zones es – Var Vary y wit ith h Die Diele lect ctrric Const Constan antt • To St Sta abilize the Gu Guiide Si Sid de Fo Forrces Ei Eitther Install in a St Stiillin Well or Fix the Guide to the Tank Bottom • Cen entter ering ing Discs which pr prev even entt the Gui Guide de from from Cont ontact acting ing the • Weigh Weights Sh S hou ould ld be used used wh when Inst Install allin ing g Flex Flexib ible le Guides Guides • Inlet Inlets ss shou hould ld be ke kept pt at a Distance Distance to Avoid S plashi plashing ng on the Guide • S ele elect ct Gui uid de Lengt Length Accordi According ng to th the Req Requi uire red d Measuri Measurin ng Ran e. S om ome e Guid ides es can can be Cut in the F ie ield ld Ot Oth her ers s cann cannot 34

34#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Rad adar ar Sig ign nals are are Transm Transmit ittted fr from om an Anten Ant enn na at the To To of the Tan Tank k • The Sig Sign nal is Ref Refle lect cted ed by the Measu Measurred Surface and the Echo is Detected by the Antenna • The E ch cho o has has a Sli lig ghtly Dif Difffer eren entt requency ompare o e ransm e Signal to the Distance to the Measured Surface

35

35#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Tra ransm nsmit ittter Sho hou uld be Inst nstalled alled in Locat ocation ions s wit with h a Clear Clear and Unobstructed View of the Level Surface – Keep Keep Away A way from fro m Agitator Ag itator Horizontal Bla Bl ade des, s, Fill Filling ing Inlets,, Ce Inlets Cent nter er of t he Tank Tank

• Minimum Minimum Dis Disttance that that the Tran Trans smit ittter can be be Moun Mountted from the Tank Wall • ,  Turrbulence and F oam  Tu • Installation • Tan Tank k No Nozzl zzle e Hei Hei ht ca can n Af Afffect P erformance 36

36#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Rod – Suit itab able le for Tan Tank ks wit with h Smal alll Open Openin ing gs • – Installations • P ar arab abol olic ic – Suit itab able le for Sol olid ids s and and Can wit ith hst stan and d Hea Heav v Contamination • E ach Ant Anten enn na Ty Type has has a Maxim Maximum Measur Measurin ing g Ran Rang ge and Minimum Dielectric Constant

37

37#

Level Instrumentation  –







A Lar e St S tain ainless less S teel eel Floa F loatt is At Atttached ached to a S pring by a Perforat P erforated ed Tape Tape  The  The S pring P rovides Con Const sta ant Tensi sio on, which Balances the Float on the Liquid  The  The P erforated Tape E ngages P ins on a S procket

38

38#

Level Instrumentation  –

9/2/2012

39

39#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Flu Fluiid Densi sitt • Tan Tank k Roo ooff Con onffig igu uratio ion n • Av Ava ail ilab abil ilit ity y of 120 VAC P ow owe er

40

40#

Levell IIns Leve nstru trumenta mentatio tion n  –

• F loa loatt Lev evel el Sw Swit itch ches es use a Floa F loatt an and d Mag Magn net etic ic Coupling Action •

s e oa ses or a s w a qu , oves a Sleeve into or out of a Magnetic Field, Causing Switch O eration

• A Non Non-Magn -Magnet etic ic Barr Barrier Is Isolat olates es th the Sw S wit itch ch Mechanisms from the Liquid

41

41#

Levell IIns Leve nstru trumenta mentatio tion n  – 

Float Swit Switch ch Configurations Config urations – er c a – op oun e – Horizontal id e Mount ou nte ed – Side

42

42#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Based on on Tim ime e Dom Domain Ref eflect lectom omet etrry  TDR  TD R • Ult Ultrraso son nic P ulse Sig ign nals are are  Tra  Tr ansm smiitted from the Tr Tra ansm smiitter and are Reflected from the Liquid Surface • The Tran Transm smit ittter Rec ecei eiv ves th the e ec e gna an easures e  Tim  Ti me-D -De elay Be Bettween Tr Tra ansm smiitting and Receivin

43

43#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Moun Mount Tran ansm smit ittter as Near to Vert Vertical as Poss P ossib ible le • • Min Minim imu um Tan ank k Nozzle Hei Heig ght • • Do not not Mou Moun nt Ove Overr an an Inle Inlett Strea eam m •  Turrbulence and F oaming  Tu

44

44#

Level Instrumentation  –



A Measure of the Amount of Energy that can be

Capacitance is Influenced by Three Factors: 



Size of the Electrode Plates



45

45#

Level Instrumentation  – Operating Philosophy 





As Level Covers the Sensing Probe, the Capacitance Between the P robe and and Condu Conduct ctive ive Media or the the Probe P robe and and tthe he Vessel Vessel Wall Increases A Bridge Misbalance is Created which is Amplified and Converted to an Output that Corresponds to the Level the Vessel s ec no ogy oes not easu surre t e mount o nergy tore , but Rather the Amount of Energy that can be Stored

46

46#

Levell IIns Leve nstru trumenta mentatio tion n  –

• Do not not Mou Moun nt in an Inle Inlett Strea eam m • • Us Use e Bra Brack cket ets s an and d Su Suppor ortts in Agi Agittat ated ed Vess Vessels els • Vessels • No Nozzl zzle e Diamete • P robe Co Coa ating

47

47#

Level Instrumentation  –

• Sou ource rce Rad adioisot ioisotope opes s used for for Lev evel el Measure Measurem men entt E mit Gam amm ma Radiat R adiation ion that that P enet enetrat rates es the Vess Vessel Wall Wall and rocess e a • A Targ Target et Det Detect ector or on the Opp pposite osite side Measures the the Radiation Field Strength and Infers a Level in the Vessel • The Rad adiom iomet etric ric or or Nucleon Nucleonic ic Prin P rincip ciple le is Based on the Fact that Gamma Radiation is Attenuated when it P en enet etrrat ates es a Mat Mater eria iall • Cesium 13 137 7 (Half Life 30 Y ear ears) s) and Cob obalt alt 60 (Half Life 5.26 Years) are the Most Commonly Used Industrial

48

48#

Level Instrumentation  –

of Radiation Received and Hence the Level in the Vessel • Lead Lin ined ed Sou ource rce Holder Holders s Con C onttain Rad adioact ioactiv ive e Mater Material ial with a Slit to Send a Narrow (in Horizontal Plane) Fan Beam Across the Vessel • Sou ourrce St S tren eng gth has has to to Con Conside siderr Vessel Vessel Wall Th Thick ickn ness • Nucleonic Level is Considered for the Most Difficult Applications such as High Temperatures and Pressures,  Tox  To xic, St Stiicky/Bl Blo ocking Materials. It is Us Use ed as a La Last st .

49

49#

Level Instrumentation  –

DETECTOR

SOURCE

DETECTOR

SOURCE

50

50#

Level Instrumentation  – • Tan ank k Gaugin Gauging g is associat associated ed wit ith h Lar Large ge Volu olum mes of High Value Product • Addit Addition ional al Measur Measures es are Tak Taken en to to Achie Achiev ve the the Highest Highest

51

51#

Level Instrumentation  –  This is E ss  Thi sse ential for: • oc on ro or ro uc on an a ns ns osses • Ass sset et Rep epor orttin ing g fo forr Tax P ur urp poses • Leakages • - Spec Product • Cross Check ecks s on Sh Ship Load oadin ing g/Off Load oadin ing g Flow Flow Met Meter ers s and Ship Dips

52

52#

Level Instrumentation  – Tank Invent ory Monitoring

Tank Fa Farm rm Level Configuration Radar Level Measurement on Fix

Float and Tape Tape Level Measur Measurement ement on Fixed Roof Tanks

Multiplexer  Radar Level Measurement on Fl oa oat in in Ro of of Tan k s

  n   o    i    t   a   c    i   n   u

Local Displ ay and and Multiplexer 

Measurement on Spheres

  m   o    C   s   u    B

Local Displ ay and and Multiplexer 

53

53#

Levell Ins Leve Instru trumenta mentati tion on • There is no single level meas measur urem ement ent techniqu echnique e that that will wor n a app cat ons. • P rop roper er ins installat allation ion is im impor porttant for level not not just for for accuracy accuracy but for getting a measurement reading at all.

54

54#

QUESTIONS

 An  A n y Ques Qu estt i o n s ? ? ?

55#

Tha hank nks s for f or you y ourr attenda attendance nce

56#