Mokveld-Brochure Angle Choke Valve En

7/22/2019 Mokveld-Brochure Angle Choke Valve En

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anglechokevalveversatile heavy duty valve or severe applications


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Innovate to meet

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The early days Mokveld was ounded in 1922 in Gouda in The Netherlands, as a smallmachine repair shop. In the mid-ties we started making valves, a development which accelerated when

the Nederlandse Aardolie Maatschappij B.V. (joint venture between Shell and ExxonMobil) discovered the

Groningen gas eld in 1959. Mokveld started delivering valves or the production o the billions o cubic

meters o gas and over the years was challenged to respond to constant changes with respect to saety,

noise and emissions. By adapting and responding eciently to the changes o the gas and oil industry our

organisation has gained an excellent reputation as an international supplier o quality valve products.


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industry demands

Mokveld headquarters

The headquarters and high-tech production

acilities are located in Gouda, The Netherlands

(area 14.000 m2 or 150.000 t2)

Full-scale erosion testing

Full-scale sand erosion testing o newly

developed choke at Advantica Flow Centre (UK)

through third party Det Norske Veritas (DNV).

Fire-safe testing

Upon request choke valves can be supplied

with re-sae certication. This illustrates

Mokvelds intense ocus on saety.

Industry challengesMokveld is committed to contribute to sae, reliable and sustainable development o the worlds energy and water

resources. Our track record o satised customers shows our capability or selecting control solutions, designing

saety systems and managing projects successully. The integrated choke valve systems described in this brochure

will help to meet your industry and project challenges.

Worldwide experienceMokveld has extensive experience in designing and manuacturing valves or the gas and oil industry worldwide.

The product portolio comprises a wide range o valve products, tailor-made to application and customer specications;

control products saety products

angle choke valves axial on-o valves (or HIPPS)

axial choke valves axial surge-relie valves

axial control valves axial check valves

In addition a ull range o pneumatic and hydraulic actuators with tailored control arrangements are available or

accurate control and reliable operation o your production.

Successul innovationRegular contact with end-users and our amiliarity with a wide variety o applications provide us with all the elements

required or innovation. Recently we have engineered and successully applied novel trim designs, subsea check

valves and a new actuator line. In cooperation with our customers we have developed a subsea control valve which

urther enhanced our knowledge about sealing technology. Mokveld has extensive expertise in the eld o material

selection and fow management. This expertise delivers new choke valve technology. A ull-scale sand erosion test

o the newly developed choke valve has conrmed a signicant improvement in erosion resistance.


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Choke valve selection is oten based on early lie production process data

and capital expenditure (valve price). However, choke valves are critical

elements in production acilities. Malunction or ailure o a choke valve

can seriously aect saety, the environment and production rates. Valve

selection should be based on sound technical and economic arguments

and long-term perspectives. Mokvelds angle choke valves have a proven

reliability in terms o perormance and will reduce costly maintenance

and production loss.

Realizing


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.

World-class valves based on new technology

Step changes in valve designIn the 1970s Mokveld was challenged to produce an angle choke valve, and pioneered piston-in-cage control

valve technology or angle chokes. The cage-guided-piston choke proved a major improvement in durability and

controllability compared to the conventional needle-in-seat choke design. Our external sleeve choke was launched

in 1982, however, we learned that or severe service the cage-guided-piston principle oered better possibil ities.

This cage-guided-piston design became the oundation or consecutive Mokveld choke generations that served as a

benchmark o availability or the choke valve industry.

The newest generationBased on its growing expertise o materials and fow patterns, and in close cooperation with customers and third-

party organizations, Mokveld continued to improve its angle choke valve designs using the Total Velocity Management

(TVM) design concept and advanced tools such as Finite Element Analyses and Computational Fluid Dynamics. A new

generation choke valve, the TVM angle choke valve, is the result. Full-scale sand erosion tests conrmed a signicant

improvement in erosion resistance. The erosion o this new angle choke valve was reduced by actor 4 compared to

conventional designs.

Over a period o 30 years Mokvelds angle choke valves have exceeded 100 000 cumulative years o operational

time in severe duty applications. We are proud to be recognized as the worldwide leading supplier o choke valves.

The company is condent that the Mokveld choke valve will serve as an industry benchmark or many years to come

and will be the valve type o choice or companies that value saety and production availability.

long-term benets

4116 / API 5000 Angle Choke Valve

Application : Hydro Carbon Production

Challenge : High H2S content

Location : Harweel (Oman, 2006)

3 / API 15 000 Angle Choke Valve

Application : Hydro Carbon Production

Challenge : Low noise and erosion resistance

Location : Dina (China 2008)

8 / ASME 1500 Angle Choke Valve

Application : Water Injection Dump

Challenge : Avoid cavitation

Location : Sirri (Iran, 2004)


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Total Velocity Management

Operationalbenets

FloSae beanThe choke can be

supplied with a FloSae

bean to provide ultimate

protection against relie

system overload.

Highturndown

High capacity and

accurate control eatures

make the valve appropriate

or both start-up and well

depletion production

scenarios.

Accuratecontrol

Static and dynamic orces on

the control element (piston)

are minimized. Accurate

control - also with

minimum opening -

is achieved.

AvailabilityImproved fow

management avoids vibration

and reduces erosion by a

actor 4. This signicantly

maximizes production

availability.

Saety bonnetThe threaded bonnet

prevents the well-known

closed-in pressure risk with

disassembly, associated with

bolted bonnet chokes.

Fire-saeTo provide additional

protection or assets and

operators, all choke valves

can be supplied with

re-sae certication.

Saetybenets


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ReliabilityTotal Velocity Management

is vital or reliable choke valve

operation. Increased reliability

reduces the total cost o

ownership and minimizes

unplanned process

downtime.

Easymaintenance

With angle transmission

installed, the choke valve can be

maintained without removal o

actuator and instrument con-necti-

ons. This will also oer

more fexibility in instal-

lation layout.

Signicantcost savings

key to availability

CompactAs a result o the low

actuation orce requirement,

small actuators can be used;

combined with a compact

valve body design this mini-

mizes the installations

ootprint.


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Mokvelds Total Velocity Management conceptLocal high fuid velocities due to preerential fow paths are the prime source

o noise, erosion, vibration and malunction resulting rom unbalanced orces.

Prevention is better than a cure. Mokvelds Total Velocity Management

concept is an intelligent valve design that careully manages fuid velocity in all

areas o the valve (trim and body) by smart engineering o the relevant valve

parts. Source treatment by Total Velocity Management is key to reliability.

Improved ow path design

The basic rules to minimize erosion in valves are:

minimize the velocity o the medium

minimize abrupt changes in fow direction

select erosion resistant materials

Although any angle type choke valve is inherently more susceptible to

erosion than an axial type, Mokveld has redesigned the entire fow path to

minimize this adverse eect. Clever engineering o the fow and velocity

patterns in the gallery, trim and outlet area can reduce erosion signicantly.

As a result o many years o research, testing and 3D CFD studies, we

managed to eliminate turbulent fow in the gallery area, evenly distribute

the fow through the cage (ull surround fow path) and to reduce velocity

through the bean. This ensures reliable valve perormance as vibration

and unbalanced orces are avoided and erosion is reduced by a actor 4.

With a minimum o turbulence and change in the fuid velocity, the energy

conversion in the valve body itsel is limited. The pressure drop is mainly

over the trim, which has been specically designed to withstand high

erosional velocities. Our standard design includes a cage, piston and bean

o solid high-quality Tungsten Carbide with the grade selected depending

on the service.

Top view Top view

Gallery / Cage Gallery / Cage

Increased reliability and

Conventional choke valve

Preerential fow through cage acing leads to

unbalanced trim orces and excessive erosion

o valve body and trim parts.

TVM choke valve

The Total Velocity Management concept

reduces choke erosion by actor 4. This results

in increased production availability.

TVM choke valve

The angled shape o a choke valve causes an

abrupt change in fow direction. TVM eliminates

erosion damage caused by preerential fow.

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Our cage-guided-piston design - your preerred choiceTo improve erosion resistance reputable choke suppliers use solid Tungsten Carbide or the throttling parts. Because

o the brittleness o this material, the cage needs to be rmly secured in the valve body. For reliability reasons Mokveld

has selected the cage-guided-piston design or its choke valve designs. The advantage o this design is that the cage

can be rmly secured in the valve body and the piston can be guided over the ull length o the stroke. This results in

minimum sensitivity o the cage and piston to: fow-induced side loads

vibration-induced atigue and

impact by particles

In addition, the fow area around the cage (the gallery area) is wide, which results in low velocities eectively reducing

erosion o the cage and choke body.

High rangeabilityTodays gas eld developments operate at high wellhead pressures and oten process aggressive fuids with entrained

sand and other solid particles. For start-up scenarios at high pressure, the capacity requirement is relatively low.

However, at the well depletion stage the capacity through the valve is generally high. Mokvelds cage-guided-piston

choke can handle high and low pressures as well as low and high fow rates, without the need to replace the trim.

In closed position the shut-o is class V.

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reduced operational costs

2nd Mokveld generation

External sleeve choke valve

4th Mokveld generation

Cage-guided-piston choke valve

Latest Mokveld generation

TVM angle choke valve

Historic development of Mokveld choke valves


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Setting the toneSaety rstFluids that include sand and other particles at conditions with high pressures,

temperatures and velocities mean that the perormance o a choke valve

is critical. Can saety be assured or personnel, the installation and the

environment under all circumstances?

Saety bonnetAccording to API 6A / ISO 10423 ( 10.9.3.6) chokes shall be designed

to vent trapped pressure prior to releasing the body-to-bonnet connector.

The Mokveld saety bonnet is an intrinsically sae solution which oers

a high level o security compared to the conventional bolted bonnet design.

When maintenance is required with a bolted bonnet choke, the engineer

can easily orget to open the relie and vent trapped pressure. Ater removal

o a ew bolts the remaining bolts may not be strong enough to contain the

pressure behind the bonnet; the bolts will break and the bonnet is ejected

with dangerous orce potentially causing atal injuries.

The Mokveld saety bonnet is screwed into the choke body by means

o sel-locking thread. Thereore, when pressure is trapped it will not be

possible to unscrew the bonnet. At low residual pressure the engineer

may succeed in turning the bonnet and the design will automatically start

venting at 15% opening. The remaining thread is more than sucient

to contain the ull rated pressure hence preventing accidents.

Low emission and fre saeThe high-integrity valve body is an integral casting or orging, without

any welds or bolted parts and no leak paths to the atmosphere other than

the bonnet/stem assembly. The excellent sealing system ensures compliance

with all international standards or ugitive emission. Optionally the choke

can be supplied with leak detection o the dynamic stem seal. For certied

re-sae execution, a redundant stem seal is provided.

Mokveld safety bonnet

The bonnet is screwed into the body by means

o sel-locking thread. Any residual pressure

will automatically be vented at 15% opening.

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or saety and control

FloSae beanThere are three material properties that are critical to the longevity o the trim: resistance against erosion, corrosion

and impact. The Tungsten Carbide grade used in Mokveld choke valve trims proves to be among the top perormers

with regard to these aspects, and will thereore give outstanding perormance.

Sometimes, a choke valve is considered as a saety device to prevent overload o the relie system. In that case it

is o paramount importance that the valve capacity does not exceed predened limits under any circumstances.

Although unlikely, the worst scenario would be a collapse o the trim upon impact o parts. One solution that

Mokveld oers, is to improve the impact resistance by adding a ortiying steel outer cage. This, however, is not an

ultimately sae solution as the steel ortication cage is subject to erosion which will reduce its unctionality over time.

The optimum solution is to separate the choke valves control and saety unction. Following an evaluation o your

process conditions Mokveld choke valves can be equipped with a FloSae bean to provide ultimate protection against

relie system overload. The custommade FloSae bean is capacity balanced with the cage and the available faring

capacity. During normal operation the bean does not infuence the choke control characteristic, but in case o cage

collapse the FloSae bean will limit the fow rate to an acceptable faring rate.

Custom designed trimStandard and custom designed trims can be selected or various applications. The all-round RQX trim is most

commonly used. This single-stage, multi-hole trim oers accurate control and high noise abatement. The holes are

o a suciently large size to avoid clogging at normal production applications. The RQX trim is suitable or a wide

operating envelope, which diminishes the need or replacement at a later stage. For more extreme conditions, a

selection o multi-stage, labyrinth-style cages is available oering very high noise abatement and/or high anti-cavitation

coecients. It should be noted, however, that in a normal production environment labyrinth-style cages work as a

strainer and may cause the choke to clog. During dirty well clean-up service a RCU large hole trim can be installed.

At well depletion stage a RDS cage will almost eliminate pressure loss over the choke.

All trims can be provided with reduced capacity and linear or equal% control characteristics. Together with the long

valve stroke this is the optimum recipe or accurate control o your process.

Selection of single-stage trim

The all-round RQX trim is suitable or high to

low pressure drops oering high capacity and

considerable noise abatement.

Selection of multi-stage trims

Multi-stage trims are designed or high noise

abatement or to avoid cavitation at high

pressure gas, two-phase or liquid applications.

Ultimate safety choke

This choke has a FloSae bean to provide

ultimate protection against system overload and

can be provided with a steel ortication cage.


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Small actuators or reliable

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Low actuation orce and small actuatorsHigh static and dynamic valve orces may lead to operational problems

and require powerul and large size actuators. As a result o the

evenly distributed fow through the cage, the dynamic orces on piston

operation are relatively small. Mokveld choke valves are tted with

a pressure-balanced piston assembly. The operating thrust/torque is

virtually independent o the dierential pressure across the valve.

Thereore, manually operated chokes do not require intermediate

gear boxes and or automatic operation the required actuators are

small and light.

balanced pressure orceevenly distributed fow or

minimal dynamic orce


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and accurate control

Hand wheel actuation

The torque to operate our chokes is very

low. Small hand wheels are also sucient to

operate the choke at ull pressure dierentials.

Mokveld stepping actuator

Very accurate control with repeatable

positioning is obtained by means o the

pneumatic or hydraulic stepping actuator.

Mokveld linear piston actuator

For a relatively quick response to process

changes, the choke can be operated

with pneumatic or hydraulic piston actuators.

Easy maintenance accessibilityThe total number o individual parts and the weight/size o internals are ar less compared to other choke valve designs.

This ensures easier access and easier disassembly and assembly o the valves. To minimize lost production time due to

actuator disconnection and removal, Mokveld oers angle transmission. Removal o the cover plates and levers

provides ull access or removal o the choke bonnet and internals. The angle transmission will also oer more

fexibility in installation lay-out.

Integrated actuator and control systemsA ull range o matching Mokveld pneumatic and hydraulic actuators with tailored control arrangements is available or

accurate control and reliable operation o your production. Electric and electro-hydraulic actuation is also available.

Depending on unctional requirements, a variety o control arrangements can be engineered. All our choke valve

products are ully integrated, operational systems. Each component is careully selected and then tested during the

various stages o a project to ensure balanced and trouble ree start-up and operation.


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Comprehensive scopeValve range

Our range o choke valve designs covers the ASME and API ratings that are commonly applied in the gas and oilindustry, up to API 15 000 (1035 bar design pressure) with related temperature ratings. For the -100 C to 200 C

(-148 F to 390 F) temperature range we oer special sealing solutions. The choke valves can be supplied with

a variety o inlet and outlet connections such as fanges and clamp connectors and sizes up to and including

12" in the ASME ratings and 13 58" in the API ratings.

Choke valve Pressure rating

nom. body size PN 150 PN 250 PN 420 PN 345 PN 690

mm (") ANSI 900 ANSI 1500 ANSI 2500 API 5000 API 10 000

200 (8")

Larger sizes and higher pressures (incl. API 15 000) on request. The complete table with valve si zes and ratings can be downloaded rom www.mokveld.com

Extensive material selectionMokveld valve products are tailored towards the changing needs o the gas and oil market. We take into account

that the medium will requently contain ree water, chlorides, CO2, H

2S, and other corrosive compounds. Thereore

valves are available in a wide range o body materials, varying rom plain carbon steel to nickel-based materials.

For the valve internals, matching material selections are available, sometimes engineered to order. To avoid problems

related to explosive decompression the standard seal selection is non-elastomeric HP lipseals.

Quality and health, saety and environmentAt Mokveld we consider quality and health, saety and environment prime objectives or the successul completion o

any project. An integrated QHSE management system ocuses on continuous improvement. We aim to build customer

trust and condence through a quality o products and service that meets customers requirements and expectations.

In-house valve test acilities are available or hydrostatic and gas body and seat tests under ambient or cryogenic

temperatures. All our products are designed and built in accordance with the required international standards and

certied by recognized authorities such as Lloyds and the American Petroleum Institute (API). Our valve designs

comply with the standards that are most requently used in the gas and oil industries, i.e. PED, API 6A-ISO 10423,

API 6D-ISO 14313 and ASME B16.34. Next to these we are also amiliar with NORSOK, Russian GOST and a variety

o standards specic to certain countries, users and projects. Mokveld quality and environment management systems

have been certied according to NEN-EN-ISO 9001:2008 and 14001:2004 and OHSAS 18001:2007. We also hold

various customer and country specic certicates. A copy o our QHSE-manual can be submitted on request.


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axial choke valvesymetrical fow path shaped or erosive applications

axial controlvalvestreamlined fow path design or demanding applications

angle chokevalveversatile heavy duty valve or severe applications

axial on-ovalvebalanced piston valve or special applications

axial surgerelievalve

pilot activated surge protector or liquid applications

axial checkvalveast acting non-slam protection or critical applications

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at top quality

For urtherinormation

contact:

Mokveld Valves BVwww.mokveld.com

Copyright

Mokveld Valves,

The Netherlands.

April 2012


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global network - supported locally

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Mokveld Ofces

1 Mokveld Valves BV

2 Mokveld USA Inc

3 Mokveld UK Ltd

4 Mokveld Norge AS

5 Mokveld Central Europe GmbH

6 Mokveld Marketing JV

7 Mokveld Valves BV, Middle East

8 Mokveld Valves BV, Saudi Arabia

9 Mokveld Valves BV, Asia Pacic

10 Mokveld Valves BV, China

11 Mokveld Valves BV, Algeria

Adresses

Gouda, The Netherlands

Houston (Tx), United States o America

Cirencester, United Kingdom

Stavanger, Norway

Oberhausen, Germany

Sumy, Ukraine

Dubai, United Arab Emirates

Al Khobar, Saudi Arabia

Kuala Lumpur, Malaysia

Beijing, the Peoples Republic o China

Alger, Algeria

E-mail

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

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Mokveld-Brochure Angle Choke Valve En