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Sizing control valvesMake sure you get the

right readings – pages 4 & 5

Know-how for the effective control of steam and fluid systems

The importance of project management – page 3

How to save energy – page 7

Spirax Steam Alliance launched – page 8

Also in this issue:

Issue 1 • 2005

connexions Issue 1 2005 v7 19/1/05 3:50 pm Page 3

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“It will take a while to confirm the cost savings,” says Mr Mustchin, “but we’re definitely using fewerchemicals and it’s more efficient to heat the water in the tank, rather than the boiler. We’re really pleased – I just wish we’d made the change earlier.”

The sparge pipe was also noisy and caused vibration, which was a bigconcern. “Anyone working in theboilerhouse had to wearear protectors,” says Mr Mustchin.

“Since we fitted the Spirax Sarcoinjector we haven’t had a single problem.”

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took longer to generate steam, which led to steam supply problems.Inconsistent feedwater temperaturealso meant that extra treatmentchemicals were needed to protect the boiler, because cooler water holds more of the dissolved oxygen that causes corrosion.

Spirax Sarco has solved a severe noiseproblem and overcome shortages ofsterilisation steam by installing a steaminjector in the boiler feedtank atHeveco Mushrooms in West Sussex.The injector is also cutting theconsumption of water treatmentchemicals by an estimated 75%.

Heveco is a major supplier ofmushrooms to the UK retail market.A crucial part of the farm’s intensiveoperation is sterilisation using steam at 5.5 bar g. “We need continuity ofproduction and efficient sterilisation is key to maintaining optimalperformance,” says Heveco’s Plant Engineer, Mr Steve Mustchin.

The new steam injector replaces asparge pipe (a tube drilled with holes)to mix steam with the water in theboiler feedtank. The sparge pipe wasinefficient, resulting in an inconsistentboiler feedwater temperature. Whenthe feedwater temperature was low,the boiler used excessive energy and

Steam injector brings quiet efficiency

find out more: Circle 1 on the reply card or visit www.spiraxsarco.com/ukand click Connexions1

Spirax Sarco Clean Steam Generator Engineered Systems substantially cut the time required fordesign, commissioning and installation.

Spirax Sarco equipment is helping to achievecost savings in the production of mushrooms.

Clean steam generator meets sterilisation needsRoss Hall Hospital produces up to 2,000 kg/h of clean steam at 3 bar g,which is used to decontaminatemedical instruments. The first step is awashing cycle, with the water heateddirectly by clean steam. This is followedby a packaging line, after which thewrapped instruments are sterilisedusing more clean steam at 134°C and2.5 bar g. The packs are then dried

thoroughly to prevent condensationbuilding up on the inside as they cool,prior to dispatch.

The equipment used throughoutthe process is stainless steel. “It’sdesigned to provide an environmentvery much like a pharmaceutical plant,”says Mr Steve Buchan, Chief Engineerat Ross Hall Hospital. In accordancewith this need, the CSG10 has 316Lstainless steel clean steam wetted partsto withstand the corrosive effects ofdemineralised water, eliminating therisk of steam contamination anddegrading of the process.

“We’ve only been up and runningfor a short time,” says Mr Buchan. “It’s a complex plant andso far everything isrunning smoothly. We’ve been verypleased with theequipment andsupport we’ve received from Spirax Sarco.”


A Spirax Sarco clean steam generator ismeeting increased demand for cleansteam from a new state-of-the-artsterilisation facility at Ross Hall Hospitalin Glasgow. The CSG10 is a completepre-assembled engineered system thatuses existing plant steam to heatdemineralised water to produce highquality steam.

The CSG10 Engineered System at


www.spiraxsarco.com/uk


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Project management key to success

Three Spirax Sarco Low Temperature Hot Water (LTHW) Engineered Systems installed at Russells Hall Hospital.

Spirax Sarco’s projectmanagement capabilityhelped ensure the success ofa major contract involvingmore than £1 million ofequipment at Russells HallHospital. Here’s how.

position,” explains Mr Pickering. “Wemet all delivery time slots, which weresometimes only ten minutes long.”

Reduce site workloadMuch of the Spirax Sarco equipmentfor the project was supplied asEngineered Systems, Spirax Sarco’spackaged steam plant delivered on askid ready for installation. As well asfast installation on site, this modularapproach offers many advantages.Fabricating systems in a workshop isquicker and safer than on a busybuilding site, and time is saved at thecommissioning stage because qualitycontrol procedures such as pressuretesting can be carried out before thesystems arrive.

“On a project with such a longlifetime, it’s also reassuring for thecustomer to know that asa long-establishedcompany, Spirax Sarcowill be offering itsservice for the full lifetime of theinstallation,” concludesMr Pickering.

Spirax Sarco’s project management skillshave proved to be a vital ingredient inthe smooth running of one of the UK’slargest hospital redevelopments,Russells Hall Hospital in the WestMidlands. Spirax Sarco has suppliedalmost £1.25 million of equipment tothe project, but it is the company’s aftersales service that subsequentlydistinguished it in the eyes of thecustomer and the contractors involved.

“I’d give Spirax Sarco 9/10 forcustomer care,” says Mr Graham Poole,Project Engineer for Haden Young, thecontractor that ordered the steamequipment as part of the £150 millionproject in Dudley. “Once they’ve soldthe goods, too many companies are not interested in helping clients,” hesays, “but Spirax Sarco was alwayswilling to come round and help withany problems.”

As a normal part of their service,Spirax Sarco project managers regularlyvisited the site to check the installationand provide expert guidance.

“We deliver an unusually high levelof help and advice on how to installequipment,” says Mr John Pickering,Project Manager at Spirax Sarco. “Asequipment was delivered, I routinelyvisited once a week to inspect theinstallation. If anything was awry, Icould alert the contractor immediately.Spirax Sarco commissioned all itsequipment and I was closely involved inthe weekly commissioning meetings onsite with the customer and during thecommissioning itself.

“In a project this size it’s really apartnership, with the supplier and thecontractor both having to do their bit,”says Mr Pickering. “Haden Young is a very professional company to deal with.”

Accurate delivery timesCoordinating such an enormous project is a huge job and suppliers such as Spirax Sarco are important inkeeping the project on track. The detailis vital, for example ensuring allequipment is correctly tagged foridentification and meeting highlyaccurate delivery times, which wereparticularly critical for this project.

A complex delivery schedule calledfor up to three deliveries a day fromSpirax Sarco. “Delivery was tightlycoordinated with the availability ofheavy cranes to move equipment into




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Control valve sizing –It may seem a straightforward procedure, but correctly sizing controlvalves for steam systems holds many potential pitfalls for theinexperienced. In this article, Connexions gives some basic pointerson this complex process.

Spirax Sarco offers same daydespatch of its most popular control valves to sites suffering abreakdown or with other urgentdelivery needs. For orders receivedearly in the day, valves can beassembled, tested and despatchedsame day to any UK address

according to the customer’s choice ofdelivery, for example before 9am.

What’s more, there is no extracost for this rapid Spirax Sarcoresponse. The only extra costs arethose for the carrier.

For rapid delivery, call 01242 521361

Valves delivered next day

Spirax Sarco offers a wide range of electrically and pneumatically actuated control valves, plusthe sizing and selection know-how to help specify control systems for almost any application.

Whether used for simple heatingcontrol or as part of a sophisticatedprocess control system, steamcontrol valves must be accuratelyspecified. Correct sizing is essentialto ensure the most accurate andreliable control possible and also to help avoid problems such asnoise and erosion.

For example, even if the valvetrim is sized correctly for thecontrol application, if the valvebody is too small, steam velocitiesin the outlet can createunacceptable noise.

For a flavour of the problemsthat can be created, please see A balancing act on page 5.

Expert help is at handWith so many factors to consider,specifying control valves can bedaunting. The best way of avoidingthe many potential difficulties is touse a supplier that has the requiredknow-how as well as the products.When ordering a control valve fromSpirax Sarco, the company’s expertswill automatically carry out thedetailed sizing.

This saves time for the customer and, more importantly,ensures an accurately workingcontrol valve that gives a long life and reliable performance.

C Series for precise controlSpirax Sarco C Series control valves are highspecificationpneumatically actuatedtwo port valves thatprovide excellentprocess control over high differentialpressures.




leave it to the expertsWhen specifying a valve it is important to ensure it isnot oversized or undersized,to avoid poor control andother problems arising inthe future.

OversizingOversizing a control valve will reduceits ability to accurately regulate steam flow because the valve mustmove by a small percentage of itstotal lift to adjust the flow. This canlead to instability, with the controlsystem ‘hunting’ for the correctsetting and causing wear of the valve and actuator.

Wherever possible, size thecontrol valve so that when it ispassing the full load flowrate, the fully open valve has the largest possible pressure drop, that the system will allow. The ideal for control is often to have the critical pressure drop across the valve.

The situation is complicated furtherby the fact that the differential pressureacross a valve is not always easy todetermine. For example, in many heatexchanger applications, a valve mayexperience a higher differential pressureat lower flowrates.

UndersizingUndersized valves can be just asproblematic, reducing the performanceof downstream equipment. Anundersized valve will cause a higherpressure drop than a larger valve,restricting the steam pressure andtemperature at its outlet. This can meaninsufficient steam is fed to thedownstream process, causing inadequateheating. So an undersized valve canseverely affect the whole process.

NoiseNoise is an important considerationwhen sizing control valves. As a rule ofthumb, the control valve should bechosen so that the steam velocity in thevalve outlet does not exceed Mach 0.3.This velocity can be exceeded by usinga valve body that is too small, even

though the valve trim size suits therequired capacity. The solution is tochoose a larger valve body with areduced trim.

Some control valves, such as theSpirax Sarco C Series, offer noisereduction trims to alleviate potentialproblems. These are perforated cages that dissipate the steamenergy, to avoid the creation ofexcessive noise. In extremeconditions, two or three stage noise reduction trims can be used.

ErosionHigh velocities can also cause erosionin the downstream valve body,especially if the steam is wet at thispoint. If wet steam is likely, it isusually best to install a steamseparator upstream of the controlvalve. A separator efficiently removeswater droplets entrained in the steamflow to ensure that only dry steam isdelivered to the control valve.

See the Spirax Sarco Learning Centrefor more: www.spiraxsarco.com/learn

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Visit www.spiraxsarco.com/uk

A balancing act

Online sizingcalculatorFor a quick way to size controlvalves, visit the Spirax Sarcowebsite’s Engineering SupportCentre. The simple to use valvesizing package allows the user toselect a Kv value for a control valve, which may be useful in aproject’s early design stages or as a rough estimate of valve size. For full control valve sizing andselection, more sophisticatedsoftware is required and it is better to call one of Spirax Sarco’sexperienced specialists.

Correctly sized Spirax Sarco control valves provide high accuracy coupled with low maintenance costs.



www.spiraxsarco.com/learn

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wSteam pressurecontrol valveoffers lower costs

Spirax Sarco has extended its range of 3-port control valves withthe launch of two newversions. The QL33 cast iron and QL63stainless steel valvescomplement existingSG iron and carbonsteel versions to cover a wide range of applications.

The most commonapplication of 3-port valves is temperature control ofprocess plant or air handlingunits using hot water,cooling water or chilledwater. Spirax Sarco’swide range of valvesalso meets thedemands of almost any mixing ordiverting application,including industrialliquids, thermal oils,compressed gases,condensate and superheatedsteam. Options include PTFE soft seats for applications needing tight shut-off and graphite stem seals and extended bonnets for hightemperature applications.

The valves are available withbellows sealing for zero emissions

and significantly reducedmaintenance costs by

eliminating the need to tighten and replacegland packing.Available for pneumatic

or electric actuation, the QL 3-port valves are offered in sizes from DN15 to DN200, withPN16 to PN40 flanges and aresuitable for operating temperatures of up to 400°C.

QL valves provide a long servicelife and high reliability, coupledwith low maintenance costs.

New valves offer moreoptions for mixing

Popular steam trap range extendedThe UK’s best selling steam trap range,Spirax Sarco’s FT ball float series, hasbeen expanded with the addition of theFTGS14 version featuring a stainlesssteel base for longer life. The newversion comes with an extended fiveyear warranty, underlining the product’shigh quality andreliability. The SpiraxSarco ball float traprange provides effectivecondensate drainageand air venting forprocess, heating andmains drainageapplications.




Spirax Sarco’s new ball float trap comes with an extended five year warranty.

A new steam pressure control valve,the DP27, is being launched inFebruary by Spirax Sarco. The newvalve replaces the DP17, combiningthe highly accurate control of itspredecessor with increased resilienceto harsh operating environments,easier servicing and simpler selection.These benefits have been achieved bya redesigned pilot valveblock, new controlspring and enclosure,plus otherimprovements. TheDP27 has the sameface-to-facedimensions as the DP17, making it easyto retrofit.

The pilotvalve isprotectedfrom pipelinedebris by aneasily replacedpilot filter.





Top tips for money-saving upgradesbuild-up in the boiler, the controlleropens the blowdown valve as required to reduce contamination,therefore minimising energy loss.

Greater efficiency is also achieved by recovering the heat from the blowdown water, as it flashes to steam. Flash steam can be separated in a flash vessel and injected into the boiler feedtanksaving both energy and water.

Feedtank heating and deaerationLess fuel is needed to produce steamfrom hot feedwater. Using returnedcondensate to raise the feedwatertemperature by 6°C gives a fuel savingof 1%. Ideally, feedwater should bemaintained at 90°C.

Simply feeding condensate into the top of the feedwater tank can be inefficient. As the condensate falls through the space above thewater, vapour and energy can be lost and air admitted. A deaerator head solves the problem by mixingcondensate, flash steam and coldmake-up water as they enter thefeedwater tank.

Automatic start-up valveManpower can be saved and safety increased by installing anautomatic warm-up system. Anelectrically actuated valve controlled by a timer opensautomatically at a pre-set time and at the correct rate to slowly heat up the steam system.

Automatic systems save energy by allowing sections of plant to be shut down when not required, at night or weekends for example.

Automatic bottom boiler blowdown Manpower, energy and water savingscan be achieved by automatic boilerbottom blowdown to remove sludgefrom the boiler. This eliminates theexcessive blowdown that often resultswhen a boiler attendant manually opensthe blowdown valve.

Steam metersMeasuring energy consumption gives animportant benchmark when working toimprove energy efficiency.Steam meters can beused to detect excessiveconsumption or tocharge energy costs toindividual departments,thereby encouragingsound energymanagement.

Upgrade What it does Benefit

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Return of condensate

Blowdown heat recovery

Feedtank heating

Automatic start-up valves

Automatic boiler blowdown

Steam meters

Can be used to pre-heat boiler feedwater

Recovers heat from boiler blowdown

Raises boiler feedwater temperature

Efficiently heats up steam system

Automatically removes sludge from boiler

Monitors steam consumption

Energy, water and chemical cost savings

Energy, water and chemical cost savings

Heating feedwater by 6˚C can cut fuel consumptionby 1%

Saves energy and releases manpower resources

Prevents waste from excessive blowdown

Helps to set targets and improve energy efficiency

Why worry now about efficiency?The wholesale price of UK gas ispredicted to be 50% higher in 2005than in 2003, while the internationalsituation leaves oil prices uncertain. Itmakes more sense than ever to savesteam and cut energy consumption.

Improving steam system efficiencyneed not be a major investment.Modest measures taken wheneverbudgets allow can still yield impressiveresults. Any of the following upgradeswill boost performance and achieve ashort payback with real cost savings.

Return of condensateReturning condensate to the boiler cansave thousands of pounds per year.Condensate contains about 20% of theenergy in the steam from which itcame. Returning water to the boilerfeedtank recovers about half thisenergy, with the other half beingcontained in flash steam that can beretrieved by a flash steam vessel orpressurised condensate return system.

As well as saving energy, condensatereturn saves water and treatmentchemical costs. Effluent charges mayalso be reduced because less water isdischarged to drain.

Blowdown and heat recoverySave costs by improving the boiler waterblowdown system, which draws offwater to control boiler contamination.Many boilerhouses use blowdownvalves, manually opened at regularintervals, with any water removed beingdumped to drain.

An automatic TDS (Total DissolvedSolids) blowdown controller is a betteroption. Continuously monitoring TDS


i n s t a n t knowledge

Flash steam recovery achieves energy savings.



© Copyright 2005 Spirax Sarco is a registered trade mark of Spirax-Sarco Limited

Contacting usTechnical and Commercial SalesEngineered SystemsSteam System ServicesNorthern Ireland CustomersRepublic of Ireland Customers

To find out how to contact your local Spirax Sarco engineer Tel: 01242 535500

Spirax Sarco has added a new pipesizing tool to its web-basedEngineering Support Centre.

The Centre provides quickanswers to all those nigglingengineering calculations that cantake up valuable chunks of time.

The new tool makes it possibleto size new steam pipes usingvelocity or pressure drop, or tocheck the capacity of existingpipes. It also tackles different typesof condensate pipe separately.

The support on offer at Spirax Sarco’sweb-based Learning Centre is proving to be a valuable tool for hard-pressed engineers.

This has led to some extremelypositive visitor feedback. For example,Senior Engineer Tom Houlihan feltmoved to write: “Thank you for a mostbeneficial web site. Your steam tabledeterminations allowed me to makecritical calculations [for] a remote site. I will always be grateful to yourengineering staff for providing world-wide consultation of the highest calibre.”

Let us know what you think byposting your comments atwww.spiraxsarco.com/uk

Online advice is a hit

Diary Dates Forthcoming courses at Spirax Sarco Cheltenham:BTEC Design of Steam & Condensate Services: 7th-9th MarchBTEC Steam Boiler Plant Controls & Systems: 30th-31st MarchBTEC Introduction to Steam & Condensate Systems: 6th AprilBTEC Steam Boiler Plant Controls & Systems: 9th-10th MayDesign of Clean Steam Systems: 16th MayFor more information visit www.spiraxsarco.com/uk

Carbon Trust’s Cutting the Cost of Steam Generation Seminar17th February 2005, Cheltenham

Spirax Sarco, Charlton House, Cheltenham, Gloucestershire, GL53 8ERTel: 01242 521361 Fax: 01242 573342 Email: [email protected]: www.spiraxsarco.com/uk

Fax

01242 57334201242 53537101242 53515401242 535341045 889892

Tel

01242 52136101242 535393 01242 53504601242 535365 045 889692

Web pipe sizing tool launched

Spirax Steam Alliance simplifies NHS procurement

The new Alliance brings Spirax Sarcotogether with packaged plantroomspecialist Armstrong IntegratedSystems, control systems integratorCTH, water treatment firm Feedwaterand heat transfer specialist Alfa Laval.

Engineers can access all the onlinelearning tools by visitingwww.spiraxsarco.com/esc

Spirax Sarco has teamed up with fourcompanies in related fields to form theSpirax Steam Alliance – an effective one-stop-shop for the complete range of steam systems for the National HealthService’s hospital building programme.

Full details of Spirax Sarco’scomprehensive range of steam trainingcourses are available for the comingyear with the publication of the SteamSystem Training 2005 brochure.

The new brochureincludes an at-a-glancecourse timetable for2005, all the relevantforms and contactdetails for the SpiraxSarco Training Co-ordinator.

Set course for training

The combined expertise of thepartners enables them to offer anunrivalled, integrated approach tosteam for major NHS projects, coveringhot water, space heating andsterilisation applications.

Modular constructionand off-site testing of Alliance equipmentsaves time during thedesign of a project,since it avoids havingto specify componentsindividually.



The Spirax Steam Alliance can provide everything needed for hospital steam services.

The content of this publication is for promotional and illustrative purposes only. It is not designed or intended to give any guidance on safe working practices or other healthand safety matters. The responsible person should always ensure compliance with health and safety requirements.



www.spiraxsarco.com/esc





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