Safe Management Of Industrial Steam And Hot Water Boilers
Health and SafetyExecutiveSafe management of industrialsteam and hot water boilersA guide for owners, managers and supervisors of boilers,boiler houses and boiler plantHealth and SafetyExecutiveSafe management of industrialsteam and hot water boilersA guide for owners, managers and supervisors of boilers,boiler houses and boiler plantBackgroundAccidents involving exploding boilers have killed people, damaged plant andaffected production. These accidents resulted from problems such as inadequatelydesigned boilers, wrongly sited or wrongly installed boilers as well as boilers thatwere not correctly operated or maintained.As the manager of a workplace, you have a duty to manage the risks associatedwith that workplace. If there is a boiler installation on your premises, you mustensure it remains safe.This is a web-friendly versionof leaflet INDG436An efficient, reliable boiler is an essential requirement for many businesses, and thedowntime caused by a failed boiler can have a major effect on production, plantand people.The word ‘boiler’, in everyday use, covers a wide range of equipment, from simpledomestic hot water boilers to boilers housed within a power generation plantto convert fossil fuel to electricity. Generally, domestic hot water boilers do notproduce steam and should operate at low pressure. While some combinationboilers now operate at the pressure of the incoming cold water mains, this is still farbelow the normal operating pressure of steam-raising boilers.This leaflet applies to steam and high temperature hot water boiler plant (operatingabove 0.5 bar pressure and a temperature of 110 C). It describes a process whichyou, as a manager, can apply to assess if your boiler installation can continue to beoperated safely.Steam-raising plant and boilersFigure 1 shows a sectional view of a typical steam-raising boiler. This is known as ashell and tube boiler and is the most common type. The hot gases from the burnergo through the furnace tube and then back through the smoke tubes and out ofthe flue. The water is heated by the tubes and is contained by the main pressurecontaining part, the shell.Figure 2 shows a typical vertical boiler found in a number of factories for eithergenerating very hot water or steam.1 of 10 pages
Health and SafetyExecutive1 Main stop valve2 Safety valve213 Pressure gauge34 Oil/gas burner5 Blowdown valve6 Smoke tubes77 Feed check valve68 Feed water pump854Figure 1 Sectional view of atypical steam-raising boiler23145121 Manual gas cock2 Gas head assembly3 Steam pressure gauge4 Steam stop valve5 Air safety switch6 Water level probes1167 Control panel box8 Blowdown valve1079 Mud hole door10 Water gauge blowdown valve11 Gauge glass protector12 Safety valve98Figure 2 Typical vertical boilerSafe management of industrial steam and hot water boilers2 of 10 pages
Health and SafetyExecutiveWhat affects the safe operation of gControlsystemFigure 3 What can affectsafe boiler operation?SafetysystemLocationAll of the above factors need to be in place and adequately addressed toensure the safe operation of a boiler. If one or more of these stops working, oris inadequate, or absent, this could result in the boiler breaking down or failingcatastrophically, causing injuries and damage to property.What do I need to do?You need to determine if the risks from your boiler are at acceptable levels or ifany additional measures are required to achieve this. This will require a systematicassessment of any risks that may be present and the control measures in place toaddress them.1A risk assessment does not need to include excessive detail; however, the findingsand any actions taken should be recorded. In some cases, you may need tocontact the manufacturer, installer or other experts for the required information tocomplete the assessment.The exact considerations will depend on the site (site-specific) but may include thefollowing: The boiler specification, condition and its associated plant.The manner in which the boiler is operated and maintained.Any safe systems of work, including management and supervision.How competent your workers are and how they have been trained.How reliable your electronic control system is.Safe management of industrial steam and hot water boilers3 of 10 pages
Health and SafetyExecutive How regularly your boiler is examined and tested. The boiler house in general.Information on a number of these considerations is often found in the existingdocumentation relating to the boiler, eg manufacturer’s instructions for operationand maintenance or drawings.Boiler specification, operation and maintenanceSince installing your boiler and associated plant, there may have been a numberof changes in the process or system, resulting in a change in the amount of steamyou require. This will in turn affect the way in which the boiler is operated, whichcould end up being very different from what was envisaged when it was installed.If a boiler is not operated within its design limits, it increases the risks of fatigue,stress and corrosion, which could eventually lead to leaks, ruptures and, in extremecases, explosions. Similarly with feed water, incorrect water treatment can leadto scaling, which will again damage the boiler and could lead to premature orcatastrophic failure.In dealing with this issue, you may find it helpful to consider the following: Is there any existing documentation relating to your boiler plant? Does this documentation state how the boiler should be operated (includingoperating limits) and maintained? Can you establish (from the documentation or the manufacturer) that the boiler issuitable for the way it is intended to be operated or maintained? Look at thingslike process demands or cyclic operation. Is the boiler being operated and maintained in accordance with thedocumentation? Can you demonstrate that the people operating and maintaining your boiler aresuitably trained and competent?EquipmentThere is a wide range of safety and monitoring equipment that can be fittedto boilers, designed to help protect the boiler from operating outside the setparameters and shut it down to prevent a dangerous situation. This may includeequipment such as alarms, water-level controls, burner controls and pressure-reliefvalves.For example, with the water-level controls, the first low-water-level alarm preventsthe boiler operating when the water level is low, but allows the boiler to restart andresume operation once the water has risen to an appropriate level. The secondlow-water-level alarm is triggered at a lower level than the first and this shuts theboiler down completely and requires a manual restart.The level of control and monitoring required depends on a number of factors, butgenerally boilers with automatic control and remote monitoring systems will requiremore monitoring and control equipment than manually controlled boilers. Figures 1and 2 show the type of equipment that can typically be found on a boiler system.You may need expert help to determine whether the equipment you have on yourboiler is sufficient to operate the system safely in the way you intend.Safe management of industrial steam and hot water boilers4 of 10 pages
Health and SafetyExecutiveWater treatmentAs with all systems where water is heated there will be a potential for scaling.This can lead to a loss of efficiency or, in extreme cases, premature failure of theboiler due to either scale build-up on the internal surfaces or debris from corrosioncollecting in the bottom of the boiler. Water quality within the boiler must bemaintained to reduce the risk of overheating, corrosion, water carryover causingdestructive water hammer and build-up of solids. Water-treatment methods include: water-treatment plant, such as base exchange, demineralisation and reverseosmosis; hotwells or de-aerators; and adding chemicals.Consult a water-treatment expert to find out what is best for your system.Boiler house safetyThe boiler is only one piece of equipment within the boiler house and therewill be several other issues that require compliance with other legislation, forexample ventilation, fire and gas. A number of different technical personnel maytherefore need to be involved in aspects of boiler house safety, eg operation andmaintenance staff. It is essential that you as the owner/manager of the site ensurethere is adequate communication between these people, even though they may notbe directly employed by you.2All equipment, instrumentation and controls must be installed and maintained bysuitably qualified and experienced personnel in accordance with the manufacturer’sinstructions.Training The training boiler operators receive must be appropriate for the equipment theywill operate. The level of competence and training required must be reviewed when a systemis modified or changed, eg increased automation or remote supervision.When selecting training providers, employers must be satisfied that: the training is delivered by people who have the appropriate knowledge andassessment skills on their specific equipment;2 and trainers have enough industrial experience to put the information in the rightcontext and knowledge of the working environment in which the trainee isexpected to work.Routine testing of steam boilersRoutine testing of boiler controls, limiting devices and feed water quality is essentialto ensure the boiler continues to be safe, reliable and efficient. The routine testsrecommended by the manufacturer should be carried out as a minimum.However, in certain circumstances, more frequent testing may be needed. Forexample, where the water quality is poor and there is a high dependence onwater treatment, more frequent testing of the water and blowdown of the boilermay be required. These tests and the results should be recorded or logged (eitherelectronically or manually) and must include:Safe management of industrial steam and hot water boilers5 of 10 pages
Health and SafetyExecutive the results of the test and comparison against required values;identification of the operator;the date of the test; andany corrective action taken, if necessary.Clear written instructions of how and when to carry out routine tests should be kepton site.3Written scheme of examinationA written scheme of examination for all relevant pressure systems (includingboilers) is a legal requirement under regulation 8 of the Pressure Systems SafetyRegulations (PSSR) 2000.4It should set out the nature and frequency of examination for a pressure systemand should adequately describe the system, including all the pipework, vessels,safety devices and any other parts that could give rise to danger.It must also specify any special measures necessary to prepare the system for suchexaminations. It should always reflect the operating conditions of the system andmay need amending if these conditions change.The scheme must be certified by a competent person and be available on site atall times. The owner of the system is responsible for ensuring that a scheme hasbeen drawn up for all relevant pressure plant and that the competent person whocertifies it has sufficient relevant knowledge and experience to carry out this task.Who or what is a ‘competent person’?The use of the term ‘competent person’ will have different meanings depending onthe context in which it is used. The basic definition is a person who has sufficientknowledge and experience to make recommendations or decisions that will ensurethe equipment or process is operated and used safely.It is essential that any individual or organisation acting as a competent personshould have sufficient practical and theoretical knowledge as well as experienceof the actual systems involved. They should also be able to access any requiredspecialist services, expertise and effective support, either from within their ownorganisation or through arrangements with external bodies.The role of the competent person includes: advising the owner/user on the content of the written scheme of examination; compiling the written scheme of examination or certifying an already compiledscheme; modifying the scheme where necessary; helping the owner/user to establish the safe operating limit of a pressure system; determining the frequency of examination and stating the examinationrequirements; undertaking the periodic examinations as identified by the written schemeof examination. For a steam boiler this should include an out-of-serviceexamination (cold, off-line, open for inspection) followed by an in-serviceexamination at normal operating pressure to check that all protective and controldevices are working properly; issuing notifications of imminent danger; and issuing a report of examination and notifications of dangerous defects.Safe management of industrial steam and hot water boilers6 of 10 pages
Health and SafetyExecutiveThe competent person carrying out the periodic examinations must have sufficientknowledge and experience of the type of system to be examined to be able toidentify any defects or weaknesses that may affect the safety of the equipment. Thisperson does not need to be the same one who compiled the written scheme ofexamination, so the current or a controlled copy of the scheme should always beavailable on site.The owner of the system is responsible for arranging for the competent person tocarry out the examinations in accordance with the written scheme of examination.RecordsYou need to retain the following documentation and records: the report of the last examination under the written scheme of examination; any details of repairs or modifications to the system (including changes to theoperating parameters); any previous reports containing information relating to the safe operation of thesystem; routine testing records for the previous two years; and technical documentation supplied by the manufacturer and installer of the boilerand associated equipment.You also need to make these documents available to the boiler operator, thecompetent person and any new user or owner of the pressure equipment.Changes and modificationsA change includes anything that has the potential to significantly change any risksfrom the boiler, for example: any physical change to the boiler, or one of its components (such as watersupply); a change in competence of the operator or maintenance staff; a change in the supervision or monitoring arrangements; or a change in the environment in which the boiler is operating.You must notify a competent person of any such changes so that they candetermine whether the written scheme of examination is suitable or needs to bemodified.Safe management of industrial steam and hot water boilers7 of 10 pages
Health and SafetyExecutiveWhat do I do next?Now work your way through the flow charts and take the action indicated todemonstrate that your boiler installation can continue to be operated safely. Youmay need help from a competent person.Is there a competent managerresponsible for the boiler?NOAppoint and train aresponsible personNOAssess the competence ofyour contractors for boileroperation and supervisionNOAssess and train to ensureadequate competenceNOAssess the competence of themaintenance providersNOContact the boiler manufactureror a competent boilermaintenance companyNOObtain a copy from yourcompetent person or inspectioncompanyNOStop the boiler and contact arecognised inspection companyYESDo you have your own boileroperators and supervisors?YESAre your boiler operatorsand supervisors competent?YESDo you have your ownmaintenance personnel?YESHave they been trained orare they experienced inboiler maintenance?YESHave you a copy of the currentwritten scheme of examination?YESHave you a current thoroughexamination certificate inaccordance with the writtenscheme?YESYESHave there been anymodifications, repairs or changes(see ‘Changes and modifications’)to the operating parameters sincethe last thorough examination?Have the changes been approvedand carried out by a competentperson?NOConsult acompetent personYESNOFlow chart 1 Have you gotthe right people in place?NOAre routine tests andremedial actions beingcarried out and recorded?YESContinued use of boiler allowedas long as you can completeFlow chart 2Safe management of industrial steam and hot water boilersReview processperiodically andwhen staff change8 of 10 pages
Health and SafetyExecutiveDo you have documentaryevidence that the boiler designis suitable for your way ofoperating?NOSeek advice from themanufacturer or the competentpersonYESYES Re-assess boiler operation/Have there been any changes(see ‘Changes and modifications’)staffing and consequences ofin the risk to people on site, egfailurenew buildings or occupancylevels?NOAre there clear and accuratewritten instructions for safeoperation?NOYESHave you a process for controlling NOchanges or modifications,including to staffing, maintenanceand ways of operating?Contact the manufacturer orcompetent personDocument a process and makesure you review itYESHave you a process for ensuringthe competence of all personnel,both in-house and contractors?NODevelop and document a process.Review all staff and contractorsand train as requiredNOCheck all contacts are up to dateand arrange audits as requiredYESAre there procedures in place forcommunication and interfaceswith contractors and are theyaudited?Flow chart 2 What evidencedo you have that you areoperating your boiler safely?YESRecord findings and take theactions indicated to ensurecontinued safe useReferences1 Five steps to risk assessment Leaflet INDG163(rev2) HSE Books 2006 (singlecopy free or priced packs of 10 ISBN 978 0 7176 6189 3)www.hse.gov.uk/pubns/indg163.pdf2 Simple guide to the Provision and Use of Work Equipment Regulations 1998Leaflet INDG291 HSE Books 1999 (single copy free or priced packs of 15ISBN 978 0 7176 2429 4) www.hse.gov.uk/pubns/indg291.pdf3 Safety of pressure systems. Pressure Systems Safety Regulations 2000.Approved Code of Practice L122 HSE Books 2000 ISBN 978 0 7176 1767 84 Written schemes of examination: Pressure Systems Safety Regulations 2000Leaflet INDG178(rev1) HSE Books 2002 (single copy free or priced packs of 15ISBN 978 0 7176 2269 6) www.hse.gov.uk/pubns/indg178.pdfSafe management of industrial steam and hot water boilers9 of 10 pages
Health and SafetyExecutiveFurther readingPressure systems: Safety and you Leaflet INDG261(rev1) HSE Books 2001 (singlecopy free or priced packs of 15 ISBN 978 0 7176 1562 9)www.hse.gov.uk/pubns/indg261.pdfFire and explosion: How safe is your workplace? A short guide to the DangerousSubstances and Explosive Atmospheres Regulations Leaflet INDG370 HSE Books2002 (single copy free or priced packs of 5 ISBN 978 0 7176 2589 5)www.hse.gov.uk/pubns/indg370.pdfEquipment and Protective Systems Intended for Use in Potentially ExplosiveAtmospheres Regulations 1996 (ATEX) www.hse.gov.uk/fireandexplosion/atex.htmSafe work in confined spaces Leaflet INDG258 HSE Books 1997 (single copy freeor priced packs of 20 ISBN 978 0 7176 1442 4)www.hse.gov.uk/pubns/indg258.pdfGuidelines on safe operation of boilers BG01www.cea.org.uk and www.safed.co.ukCombustion Engineering Association Boiler Operation training schemeswww.cea.org.uk/training.aspFurther informationFor information about health and safety, or to report inconsistencies or inaccuraciesin this guidance, visit www.hse.gov.uk. You can view HSE guidance online andorder priced publications from the website. HSE priced publications are alsoavailable from bookshops.This leaflet contains notes on good practice which are not compulsory butwhich you may find helpful in considering what you need to do.This leaflet is available at www.hse.gov.uk/pubns/indg436.pdf. Crown copyright If you wish to reuse this information visitwww.hse.gov.uk/copyright.htm, for details. F
A guide for owners, managers and supervisors of boilers, boiler houses and boiler plant This is a web-friendly version of leaflet INDG436 Safe management of industrial steam and hot water boilers A guide for owners, managers and supervisors of boilers, boiler houses and boiler plant Background
17 Table 3. Compressed Water and Superheated Steam (continued) 0.01 MPa (ts 45.806 C) 0.02 MPa (t s 60.058 C) 0.03 MPa (t s 69.095 C) v ρh s t, C v h s t, C v ρ h s 26 446. 0.037 814 3076.7 9.2827 300 13 220. 0.075 645 3076.5 8.9625 300 8811.0 0.113 49 File Size: 630KBPage Count: 60Explore furtherCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comSuperheated Steam Tables - Gilson Enggilsoneng.comCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comCalculator: Superheated Steam Table TLV - A Steam .www.tlv.comSteam Table Calculator Superheated Steam Region Spirax .www.spiraxsarco.comRecommended to you b
Page 2 June 2015 Large Steam Power Plants Siemens Steam Turbines for coal-fired Steam Power Plants Power output 120 MW to 700 MW Max. steam parameters Main steam / Hot reheat steam 177 bar / 600 ºC / 620 ºC 2,570 psi / 1,110 ºF / 1,150 ºF SST-5000 series for coal-fired Steam Power Plants
2. Use the steam control to select the amount of steam you want ( m low, l medium, h high). 3.2. Squeeze the steam button to produce steam, release it to stop. NOTE: When you first start your steam station and pull the trigger for steam ironing, there will be a delay as your steam station pumps water from the reservoir to prime the system.
Superheated steam. Properties of steam Steam tables To determine various steam properties . Guide C, Section 4, or IOP Guide Total enthalpy, h g h f (sensible) h fg (latent) Extract from superheated steam tables Extract from the saturated steam tables Do you know how to use these steam tables? (Source: www.spiraxsarco.com .
4 steam tips 080106506 U09 round floor brush inox 165 mm 4 steam tips 080316572 U10 wide steam tip Menikini, due to the continuous development of its products, reserves the right for changes without prior warning. steam accessories professional & industrial steam accessories 13 SANIF
Steam Source All sterilizers are supplied ready to accept a site steam supply of 50 to 80 psi. The sterilizer steam connection is valved and trapped to accept a ½ NPT steam supply. If site steam is not available, please see the steam generator option below. Steam pipe work is constructe
Steam traps that discharge into a steam header should be checked for proper oper-ation. Badly leaking steam traps can over pressure a steam header. Examine turbines. If let down valves are not contributing to the excess steam prob-lem, steam turbines exhausting into that header should be examined. Hand valv
steam nozzle on the hand-held steam cleaner or hose. Firmly press the hose or variable nozzle onto the steam nozzle (7) of the hand-held steam cleaner or hose such that it is fully seated, and release the clips. WARNING: CInspect the seal on the steam nozzle of the hose and handheald steam cleaner before each use (Figure C). If the seal is .
