Презентация на тему «KONTROLL VENTILER»

KONTROLL VENTILER

JAN O HJETLAND

Fag disipliner

Prosess Material Instrument ”Piping” Maling Innkj?p Produksjons oppf?lging

Hvilken type kontroll ventiler har vi

Sete ventil (Globe) Kule ventil (Bal) Sving ventil (Butterfly)

Hva er en kontroll ventil

En kontroll ventil er arbeideren i en prosess lup

BUTTERFLY

Ball

Globe

CAGE

Separator Level Control

Gas

Oil

Oil

Water

Gas outlet

Oil level Control valve

Water level Control valve

Crude Inlet from well head

Ventildimensjonering og valg - fremgangsm

te

Gjenta beregningene med relevante ventildata

KURVE

Beregne ventilst

rrelse - bakgrunn

Har stort sett v?rt basert p? leverand?renes egne standarder / metoder Standardiseringsarbeide har p?g?tt siden tidlig 1960 ISA etablerte en komite i 1967 som skulle utvikle og distribuere standard ligningssett - ble til en “American National Standard” IEC benyttet ISAarbeidet som basis for ? formulere internasjonale standarder ISA og IEC standardene er harmonisert, med noen f? unntak (nomenklatur) ANSI / ISA Standard betegnes S75.01 IEC standard har betegnelsen 534-2-1 og 534-2-2 (inkompressible og kompressible medier) Disse standardene inneholder ogs? metodikk for st?yberegninger

St?y i reguleringsventiler

St?y i reguleringsventiler er en stor bidragsyter til anleggets totale bakgrunnsst?y Myndighets krav blir stadig strengere St?ykilder i et anlegg er vanskelige ? identifisere, p.g.a. mange forskjellige kilder, refleksjoner, forplantning av st?y etc. Brukere som ser bort fra st?ykravene er eksponert for un?dvendige belastninger Kontrakt?rer som garanterer ? m?te spesifikasjoner for st?y er eksponert for potensielle erstatningssaker / kostnader ved korreksjoner

Aerodynamiske st

ykilder

Linje-kilde

Tverrsnitt av r?r

For hver dobling av avstand, tapes 3 dBa

Noise Trims - Whisper I

Splits flow into small rectangular passages Increases Peak Frequency Complimentary body design Most effective dP/P1 <0.6 Up to 20 dB attenuation

Whisper III

Flow passes through small holes Level 3 Uses 1.6 mm dia Level 1 Uses 3.2 mm dia 6 dBA difference Increases frequency Complimentary body design Jet independence Up to 30 dB attenuation

Whisper III

C/d = 3.4 dP/P1< 0.99

C/d = 2.7 dP/P1 < 0.75

P2

P1

C/d = 2.0 dP/P1 < 0.6

Air Flow

WhisperFlo

Staged Reduction of Pressure Shift Frequency Spectrum Higher Unique Passage Shape Jet Independence Manages Velocity Using an Expanding Area Principle Complimentary Body Design Up to 40 dB attenuation

WhisperFlo Flow Passage

Outlet

Inlet

Lyddemper

Reduksjon av st

Begrense st

y-generering

Globe ventil med diffuser

VESKE

FLASING CAVITATION

Liquid Flow through an Orifice

Vena Contracta

Highest Velocity

Lowest Pressure

Pressure

Velocity

Cavitation

Vena Contracta

Vapour Bubbles Collapse

Vapour Bubbles Form

Pressure

Vapour Pressure

High Recovery Valves (Km= Fl2= 0.5) Line of sight valves; Butterfly,

Ball

Low Recovery Valves (Km = Fl2=0.8) Globe valves

Pressure

Pressure

Cavitation Damage

Cavitation - Path Treatment

Cover exposed areas with resistant material 316 Sst < 18 HRC 416 Sst (Std trim material) 38 HRC min 440C 56 HRC Alloy 6 (Stellite) 36 to 44 HRC Ceramic Tungsten Carbide

Cavitation - Path Treatment

Cover exposed areas with resistant material 316 Sst < 18 HRC 416 Sst (Std trim material) 38 HRC min 440C 56 HRC Alloy 6 (Stellite) 36 to 44 HRC Ceramic Tungsten Carbide

Cavitation - Path Treatment

Select body style that directs the cavitation away from surfaces ( Isolates ) Angle body Flow down Liner (Hardened Material) Hardened trim Micro-Flat Trim for low Cv requirements Cavitation is confined to the centre of the outlet passage

Cavitation - Path Treatment

Select body style that directs the cavitation away from surfaces Vee Ball Valve Reverse flow Stellited ball

Forward Flow

Reverse Flow

Cavitation - Path Treatment

Aspiration Inject air into cavitating flow stream Air bubbles absorb energy released in bubble collapse

Cavitation - Path Treatment

Cavitrol III 1 Stage Flow down Holes directly opposing Keeps any cavitation in centre of cage away from surfaces

Cavitation - Source Treatment

Treating the cause of cavitation Use valve trim that avoids cavitation Low recovery valve High FL2( KM) Change from rotary valve to globe

P1

P2

PV

Pressure

Low Recovery Valve (Km)FL2 = 0.85 No Cavitation

High Recovery Valve (Km) FL2 = 0.5 Cavitation

Hole shape

The hole is designed to maximize flow without flow separation from the wall, and with enough recovery volume for the fluid from the previous orifice .

Pilot hole and recovery volume

Controlling orifice

High Capacity Low Recovery

flow

Hole Design - Control Flow Separation

Thin Plate Low Capacity Low Recovery

Thick Plate High Capacity High Recovery

Cavitrol Hole High Capacity Low Recovery

Any cavitation that does occur is outside cage wall

Staged Pressure Drop

1st Stage 2nd Stage 3rd Stage

Standard Trim

Staged Cavitrol Trim

Note the uneven pressure drops. The first stage takes the majority of the drop so the last stage takes very little and can control Pvc very close to Pv.

P1

P2

PV

3 Stage Cavitrol III Trim

CAVITROL IV

CAV4 with Cavitrol IV Trim Trim can take pressure drops up to 448 Bar Protected seating surface eliminates significant pressure drop across seating surfaces Trim can be used in other globe or angle valves Staged clearance flows

CAV4

MINI CAV4 TRIM AVAILABLE IN 2” CLASS 1500 AND 2” CLASS 2500 DESIGN EHS VALVES 1” DIAMETER PORT, 3/4” TVL Cv RANGE - .1 TO 2.9 SAME LIMITS AND FEATURES AS STANDARD CAV4 USED FOR METHANOL LETDOWN

Special Products Group

Application

Hole size Cav III 1-stage hole size = 0.0625” or 0.125” diameter Cav III 2 and 3 stage smallest hole size (in the first stage sleeve) = 0.049” diameter Larger holes for can be used for less plugging, but will reduce cavitation protection. If larger holes are used more stages are required.

Velocity - Cavitrol

Second stage velocity lower than First stage

Outlet Stage: Average velocity = 45 ft/sec Peak velocity - 57 ft/sec

Separator Level Control

Gas

Oil

Oil

Water

Gas outlet

Oil level Control valve

Water level Control valve

Crude Inlet from well head

Produced Water/Water Injection Valves

Challenges of these applications

Cavitation High pressure drops Erosion High pressure drops Sand and other particles Corrosion Sour conditions Chloride stress cracking

Produced Water/Water Injection Valve Issues

High pressure drop Can lead to damaging cavitation and erosion Solid particulate can lead to plugging of conventional severe service trim Tight shutoff required Protects the valve from low flow damage when in the closed position Possible corrosion issues Issues with stress corrosion cracking need to be addressed Depends upon H2S and chloride concentration

Typical stacked disc trim

Erosion

Hard surfaces decreases the amount or speed of damage Alloy 6 440C Tungsten Carbide Ceramics

Increasing erosion resistance

Better Solution - Fisher NotchFlo DST

Pressure staging reduces vibration Available in 4 stages and capable of up to 180 Bar of pressure drop Ability to pass particles up to 12 mm diameter Protected seat maintains shutoff integrity Hardened materials resist erosion damage Can be used for globe or angle valve configurations

Trash Tolerance - Notchflo vs

DST

DST “Dirty Service Trim”

W6787-1

DST Flow Down

W678-1

Rotary Actuator

HOOK UP

DVC6000

E.SEAL