Fisher Valves - Critical Application O&G - Rev0 [Compatibility Mode]

8/12/2019 Fisher Valves - Critical Application O&G - Rev0 [Compatibility Mode]

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OUTGASSINGOUTGASSING

TECHNOLOGYTECHNOLOGY


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OBJECTIVESOBJECTIVESOBJECTIVESOBJECTIVES

What is out gassing?

A process by which gases dissolved in a fluid comes out of the

liquid when the liquid pressure is reduced.

Applications

Sizing & Selection


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What is OutWhat is Out--gassing ?gassing ?What is OutWhat is Out--gassing ?gassing ?

- Mixture of liquids and gases.

-erent v c.

- Exact value of Pv/ Pc not known.

- Pv > Pc

- pp ca on requ res gases o e expe e romthe liquid.

- Di erent rom lashing imilar to oda bottle


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Are Flashing & OutAre Flashing & Out--gassing Same ?gassing Same ?Are Flashing & OutAre Flashing & Out--gassing Same ?gassing Same ?

- Flashing occurs within thesame liquid. (Liquid turns tovapor as fluid has dropped

- -liquids and gases. (The gasreleased is not the originalfluid but a fraction of total.

vapor retains the samechemical makeup as theoriginal fluid.)

makeup of original fluid

- Pv/Pc known.

- Follow liquid sizing.

- Pv/Pc not known.

- Use bracketing method.(Non Std method by definingthe upper and lower bound oncapacity used to select thetrim size)

- Pv < Pc & P2 < Pv - Pv > Pc or P1


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EPC must define Pv & PcEPC must define Pv & PcEPC must define Pv & PcEPC must define Pv & Pc


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Outgassing DamageOutgassing DamageOutgassing DamageOutgassing Damage

2 types of damage are caused ;-

EROSION DAMAGE : g e oc ty ets com ng out o t e

solution, carry small liquid particles which impinges on theinternal surfaces at very high velocities causing erosions.

VIBRATIONS : The high velocity jets coming out of the solutiontend to impinge on the body wall and trim parts causing

VIBRATIONS.

SOLUTION

Breaking up of the large jets into smaller jets helps to preventroblems that cause vibration as well as article dama e.

This in FISHER is enabled by DST-G trim .


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Where Found ?Where Found ?Where Found ?Where Found ?

Oil & Gas Production Facilities

- 2 and 3 Phase se arators

Natural Gas Processing plants

- Acid Gas removal units (Amine units)

Ammonia plants

- CO2 removal units

LNG Plants

- Amine Units

Refineries

- Amine and CO2 removal units


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Main ApplicationsMain ApplicationsMain ApplicationsMain Applications

1) Rich Amine letdown.

Look for Amine/MEA/DEA/TEA Service .

2) Hot High pressure separator letdown (HHPS).

3) Cold High pressure separator letdown (CHPS).


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Rich Amine Letdown ValveRich Amine Letdown ValveRich Amine Letdown ValveRich Amine Letdown Valve


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Minimum Liquid Flow Pump Bypass ValveMinimum Liquid Flow Pump Bypass ValveMinimum Liquid Flow Pump Bypass ValveMinimum Liquid Flow Pump Bypass Valve


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Rich Amine Letdown ProcessRich Amine Letdown ProcessRich Amine Letdown ProcessRich Amine Letdown Process

Amines (DEA, MEA, Potassium Carbonate) are used to remove acidgases( H2O, CO2) from Natural gas.

Gas is fed from the bottom of the absorption tower while liquid is sprayedinto the top of the tower to contact as it flows from the top to the bottom oftower and out.

2 Severe service valves are associated:-

a) Level Valve:- Rich Amine Let down valve-

b) Liquid Pump Bypass Valve:- Used as a Minimum flow bypass valve toprotect the pump

the bottom through a rich amine letdown valve actuated by the liquid levelcontroller


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Rich Amine Letdown Process ContRich Amine Letdown Process ContRich Amine Letdown Process ContRich Amine Letdown Process Cont

Rich amine then goes to the Flash tank, operating at a low pressure and largeproportion of physically Absorbed gases are offgassed. Whole thing dependson the severity of the pressure drop experienced.

Rich amine is then regenerated and recycled for beginning the cycle again.

ressure rop occurs a e own va ve as uge press . e ween a sorp ontower and flash drum.

Causes 2 phase flow- (Liquid Amine / CO2 & H2S) - excessive erosion andv ra on.


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Selection for Amine LetdownSelection for Amine LetdownSelection for Amine LetdownSelection for Amine Letdown

- Two phase may produce excessive vibration / may be very erosive.

300 psi drop : Globe valve with standard trim styles and hardened trim,flow down (balanced valves)

300-600 psi drop :

- Use of slotted cage / drilled hole trim (Flow Up).

-available to be dissipated during Outgassing.

-> Less energy dissipation by smaller flow paths and by flowing

parts. Hardened seat, plug, Cage.

600 psi drop :

- o e age ma e o so oy . ar ene p ug an sea , ow up.- Drilled hole cage made of 17-4PH SST. A hardened valve plug and

seat ring is recommended.


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Selection for Amine Letdown ContSelection for Amine Letdown ContSelection for Amine Letdown ContSelection for Amine Letdown Cont

For Al l Pressure drop Conditions:-

Stem Size : min for 2 & over valves Max stem/ ackin area toreduce wear due to vibration.

Stem Material : Nitronic 50.

Packing : Enviroseal packing to reduce vibrations and extend packinge.

NACE : Compliance Valve due to presence of H2S gas.

Material : WC9 or SST body to reduce Erosion and Corrosion effect

*Solutions can be Multistage Trims, Sweep flow angle valve, Ball Valve

in reverse flow.


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Hot & Cold High Pressure SeparatorHot & Cold High Pressure SeparatorLetdown ValveLetdown ValveHot & Cold High Pressure SeparatorHot & Cold High Pressure SeparatorLetdown ValveLetdown Valve

Generic Hydrocracking Process Flow Diagram

PREHEATERPREHEATER REACTORREACTOR HHPSHHPS CHPSCHPS (CHPS+HHPS)(CHPS+HHPS) FRACTIONATING COLUMNFRACTIONATING COLUMN


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Hot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator Letdown

HYDROPROCESSING : HYDROTREATING and HYDROCRACKING.

-selective reactions with hydrogen in a heated catalyst bed. Removes sulfur,nitrogen and certain metal contaminants.

HYDROCRACKING;- Converts (cracks) heavy feedstocks into lightercomponents by selective reactions with hydrogen in multiple heater catalyst

beds. Commonly used to create gasoline or diesel product streams.


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Hot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator LetdowncontcontHot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator Letdowncontcont

The fresh feed is mixed with MAKEUP HYDROGEN and RECYCLE GAS

(rich in hydrogen content) and sent through a HEATER to the FIRST

REACTOR.

If feed is not hydrotreated, there is a GUARD reactor before the

hydrocracking reactor.

compounds to hydrogen sulfide (H2S), ammonia (NH3) and additional

hydrocarbons to protect the precious metal catalysts in the other reactors.

which converts 40 50 percent (volume) of the reactor effluent to

material boiling below 400 degrees.

pressure separator (HHPS) where the hydrogen-rich gases flashed offoverhead.


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Hot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator LetdowncontcontHot & Cold High Pressure Separator LetdownHot & Cold High Pressure Separator Letdowncontcont

The H2 rich gases are then sent to the CHPS for additional separationfrom which the H2 rich gases are recycled to the 1

st stage of the processfor mixing with additional H2 and the fresh feed.

The liquid effluent from both the HHPS and CHPS is sent to afractionalization column where the butane and lighter gases are taken off

,removed as liquid side streams.

CHPS.

H2 for reactor + Crude N2 / S ----------> H2S + NH3 + Li hter CrudeMetal

Catalyst


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Sour Water Letdown ValveSour Water Letdown ValveSour Water Letdown ValveSour Water Letdown Valve


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CHPS with Sour Water Letdown ValveCHPS with Sour Water Letdown ValveCHPS with Sour Water Letdown ValveCHPS with Sour Water Letdown Valve

The CHPS separates the rich hydrogen gas, which is sent to the recyclecompressor, from the liquid effluent.

e qu p ase s separa e n o recovera e pro uc s an sour wa er.

Sour water being heavy is tapped from bottom & we get light crude whichis sent to fractionating column.

pressure separator through the CHPS letdown valve.

The sour water is directed to the sour water flash drum to remove residualH2S and NH3.


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Challenges in HHPS, CHPS / Sour Water LetdownChallenges in HHPS, CHPS / Sour Water LetdownValvesValvesChallenges in HHPS, CHPS / Sour Water LetdownChallenges in HHPS, CHPS / Sour Water LetdownValvesValves

In CHPS and HHPS, a very High pressure drop of 1500/3000 and 1800/3000psig respectively exists. In Fractionating tower it is 100/300psig.

av tat on as ng amage.

Vibration.

Corrosive due to H2S/NH3.

To conform to NACE requirements.

Entrained catalyst from reactor and Flowing particulates may clog the flow.

High Temperature of 400-850 Deg F


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Slotted Cage Design as a solutionSlotted Cage Design as a solutionSlotted Cage Design as a solutionSlotted Cage Design as a solution

Multiple Orifices breaks up turbulent fluid

streams and hence reducing noise

pro uc ng n erac ons.

Acoustic energy shifts to higher

fre uencies which are not readil absorbed

by downstream piping and leads to much

less sound in audible range.

OUTGASSING, Vent to flare, Natural gas

Control and LP Steam Vent.

We need Solid Alloy 6 material for Richamine letdown service.


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Two Stage Cage DesignTwo Stage Cage DesignTwo Stage Cage DesignTwo Stage Cage Design

- Similar to Slotted cage design but

much larger slots (0.25 Inch)

1) Slotted Cage; Facilitates smaller

e orma on as e s sc arges

from cage into the body. Separated

jets leads to less damage by

vibration as contains less energy.

2) Body- Block forged body has an

expanded body cavity that allows

entrained gases to expand.Reduces Jet Dama in effect

3) A Linercan be provided to

augment valve life

4) A Protected Seat Design whereshutoff function of valve is separate

from the throttling areas of trim.


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Drilled Hole Cage as a solutionDrilled Hole Cage as a solutionDrilled Hole Cage as a solutionDrilled Hole Cage as a solution


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Dril led hole or slotted cages in flowDrilled hole or slotted cages in flow--upupdirectiondirectionDril led hole or slotted cages in flowDrilled hole or slotted cages in flow--upupdirectiondirection

Majority of pressure drop is taken across outlet of the holes in thecage.

- Erosive Gas + Liquid mixture is directed away from critical trim

parts.

- Pressure Fluctuations are removed from the bottom of the lu .

- Large jets are broken up into many smaller independent jets.

- Vibration and instability is eliminated.


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SWEEP-FLO ANGLE VALVE a en ea uresa en ea ures

Angle ValveAngle Valve

Venturi type throatVenturi type throat


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Multistage Trim DesignsMultistage Trim DesignsMultistage Trim DesignsMultistage Trim Designs


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Some Multistage Trim HighlightsSome Multistage Trim HighlightsSome Multistage Trim HighlightsSome Multistage Trim Highlights

1) Controlling the erosion.

2) Allows particulates upto in diameter to pass.

3) Eliminating cavitation and resultant noise.

4) Maintaining tight shut-off (Standard Shut off

class is Class V. Protected seat maintains

shutoff integrity).

5) Ensuring long trim life.

6) Compensates for volumetric expansion in

flashing fluids.7) Available in 2-6 stages and capable of up to

4000 psi of pressure drop

8) Common for applications like HHPS, CHPS,

.

Fisher Valves - Critical Application O&G - Rev0 [Compatibility Mode]

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