Learn about steam

Steam - the energy fluid

Here we look at the many benefits that come from using steam as an energy source. Efficient, economic, flexible, and manageable, steam is widely used by many different industries.
Steam and the organisation

Depending upon your role in your organisation, how steam is relevant to you will vary. From CEOs and managers to technicians and engineers, here we answer common questions about steam systems.
The steam and condensate loop

The steam and condensate loop explained How steam is generated, and why factors like feedwater, level control, and blowdown matter. Discover how steam gets to where it is needed, and why steam quality is important.

Engineering Units

A detailed look at the globally-agreed units used in steam system engineering. Many you will be familiar with, thanks to their widespread use, whilst we also examine those with specific relevance to steam.
What is Steam?

Here we delve into the physics that lies behind steam. Understand the triple point, saturated steam tables, steam dryness, and what is flash steam.
Superheated Steam

Explore why superheated steam is used, the two theories used to measure its efficiency, the superheated steam table, and its pros and cons.
Steam Quality

Learn about the properties that ensure steam works effectively, why noncondensable gasses matter, and what is a water hammer (and why they should be avoided).
Heat Transfer

A detailed look at how heat is transferred, the thermal conductivity of different materials, barriers to heat transfer, and the various equations needed to measure the efficiency of heat transfer.
Methods of Estimating Steam Consumption

Crucial to an efficient system, we look at the options for estimating your steam needs, both in flow and non-flow applications.
Measurement of Steam Consumption

The three main ways of calculating your steam consumption are considered; a flowmeter, condensate pump, and condensate collection.
Thermal Rating

Why your equipment's thermal rating cannot necessarily be taken as read, and the factors you will need to consider when interpreting it.
Energy Consumption of Tanks and Vats

Widely used to contain liquids, tanks and vats are either open or closed. Here we look at how you can calculate the amount of energy needed for various situations.
Heating with Coils and Jackets

A comprehensive look at submerged steam coils and steam jackets, the two most common ways of indirectly heating liquids in a vessel. The calculations needed, design, and controls are all covered.
Heating Vats and Tanks by Steam Injections

The most common method of heating boiler feed tanks, heat is transferred by direct contact between steam and the liquid. The amount of steam needed, and the factors that might affect the heat transfer rate are dealt with here.
Steam Consumption of Pipes and Air Heaters

Here we investigate how the pipes that carry steam affect the system's efficiency. The difference between warm-up and running loads are considered, and the calculations needed to measure heat loss. We also look at air heating equipment and how to assess these too.
Steam Consumption of Heat Exchangers

This section focuses on shell and tube heat exchangers and plate heat exchangers. How they are used, their design and steam consumption calculations for them are all discussed. Finally, we look at other shell and tube steam heaters.
Steam Consumption of Plant Items

Steam has many other uses. In this module we look at heater batteries, heating calorifiers, hot water storage calorifiers, drying cylinders, presses, and tracer lines. For each, we look at how steam consumption may be estimated.
Entropy - a basic understanding

A practical approach to understanding what entropy is, how it can be measured, and why entropy is so important to steam engineering.
Entropy - its practical use

Find out how Temperature-Entropy and Enthalpy-Entropy charts can help you, how kinetic energy works in steam, and why understanding control valves is so important.

Introduction

Factors to consider when choosing boilers, from local regulations, fuel options, and the various pros and cons associated with them.
Shell Boilers

A survey of various types of shell boilers, both wet and dry back. The development of the Lancashire boiler, the arrival of the packaged boiler, through to the reverse flame, or thimble boiler. We also look at the pressure and output limitations of shell boilers.
Water Tube Boilers

How water-tube boilers work, variations using the same principles (drum boilers and the Stirling boiler), and their advantages and disadvantages. We also look at combined heat and power plants (CHP), and combined cycle plants.
Miscellaneous Boiler Types Economisers and Superheaters

Used when steam isn't required all the time, and why economisers and superheaters are used.
Boiler Ratings

The three commonly used methods for measuring boiler outputs, and the equations you will need to calculate them.
Boiler Efficiency and Combustion

How the efficiency of boilers is worked out, and a survey of the different options for burners, their controls, and impact on overall effectiveness.
Boiler Fittings and Mountings

To keep your boiler operating safely and efficiently a range of other valves, controls, and accessories are needed. Here we explain the importance of each.
Steam Headers and Off Takes

Various alternatives to boiler layouts, their smooth operation, the importance of warm-up, and making sure steam is distributed properly.
Water Treatment Storage and Blowdown for Steam Boilers

An examination of the many aspects of water quality and how they might affect steam boilers.
Water for the Boiler

Options for treating water before its use in steam boilers, why carryover should be avoided, and the importance of water quality to different types of boilers are dealt with.
The Feedtank and Feedwater Conditioning

Considerations and calculations needed to optimise your boiler feedtanks, pumps, and piping. We also examine deaerators and other important elements to think about when designing an efficient system.
Controlling TDS in the Boiler Water

See how to measure TDS, maintain the correct level, and how automatic TDS control can lead to cost and efficiency savings.
Heat Recovery from Boiler Blowdown TDS Control Only

Find out how much energy can be saved, and captured, when blowdown is used to control TDS. Both flash steam and heat exchangers are looked at.
Bottom Blowdown

The term used to describe the process of removing suspended solids from a boiler. We look at how this is done, the options for blowdown, and regulations controlling its operation.
Water Levels in Steam Boilers

Crucial to their safe and efficient running, boiler water levels must be monitored and adjusted if necessary. We look at why this is important, and the effect of different loads on levels.
Methods of Detecting Water Level in Steam Boilers

Learn how level controls, low and high water alarms work, and the differences between conductivity and capacitance probes. Float controls and differential pressure cells are also reviewed.
Automatic Level Control Systems

Here we take a close look at how boiler water levels may be automatically detected, and where problems might occur.
Water Level Alarms

Too much, or too little water in your boiler is something that must be avoided. This section looks at your options for warning of either situation.
Installation of Level Controls

How to accurately gauge the water level in boilers, plus the details that will determine which method will be best for your system.
Testing Requirements in the Boiler House

A summary of how boiler testing is regularly carried out, with specific reference to the UK's regulations.
Pressurised Deaerators

A comprehensive look at how these remove unwanted gases from steam system water, and the principles and practices of their use.
Steam Accumulators

Everything you need to know about steam accumulators, from assessing requirements, sizing, design, and operation, to controls, fittings, and injectors. Comprehensive calculations are also included.

Fluids and Flow

An examination of the fundamental principles behind measuring the flow of steam, including density, viscosity, velocity, the Reynolds number, and flow regimes.
Principles of Flowmetering

An in-depth look at the science behind flowmetering, the equations used to maximise its effectiveness, and how ultrasound is used to measure flowrate.
Types of Steam Flowmeter

Discover the seven types of flowmeter used to measure steam and condensate. We consider how each works, their advantages and disadvantages, and where they are often found.
Instrumentation

Here we break down how flowmeters interpret data, why pressure variations must be considered, and understand how dryness fractions and superheat can impact accuracy.
Installation

With over a third of flowmetering problems stemming from poor installation, it's important to get the design and installation right. This section will give you a checklist for selecting the right flowmeters, and a comprehensive set of recommendations for their installation.

An introduction to controls

Here we investigate why automatic controls are more reliable than manual options, and look at how controls deal with processes that use steam, water, compressed air, and hot oils.
Basic Control Theory

Put simply, the two basic control options are either on/off or continuous control. This module looks in detail at the implications of each, paying close attention to the three elements of continuous control: proportional, integral, and derivative.
Control loops and dynamics

What is a control loop, what are the differences between control loop options (open, closed, single, multi, cascade), what happens in each control loop, and various process reactions are all answered in this topic.
Choice and Selection of Controls

How to Choose Which Controls to Use? An overview of your options (self-activating, pneumatic, electric, electro-pneumatic), a look at valves and actuators, and choices of controllers. Guided by consideration of safety, stability, and accuracy.
Installation and commissioning of controls

A detailed look at the elements involved in the installation and commissioning of controls, including how the Ziegler-Nicholls method can be used for setting controllers.
Computers in Controls

Looking at the evolution of IT helping improve control, up to the introduction of fieldbus technology in streamlining operations.

Control Valves

Get to know the different types of control valves used in steam and fluid systems. The differences between linear and rotary valves, with two or three-ports, is simply explained using animated diagrams.
Control Valve Capacity

Valves work by altering either flowrate or differential pressure. Gain an understanding of the flow coefficient, and how it is used to compare valve performance.
Control Valve Sizing For Water Systems

Here you will find out how to correctly size valves using either equations or charts. The difference between imperial and metric measurements is explained, how two- and three-port valves differ in how they operate, and why valve authority, cavitation, and flashing need to be considered.
Control Valve Sizing For Steam Systems

Your complete guide to unravelling the complicated subject of steam control valve sizing. Find out how to use formulae and steam tables to make sure you have the right sized valve, the issues you may need to consider (velocity, noise, erosion, drying, and superheated steam), together with a checklist of the 20 major factors to assess your system.
Control Valve Characteristics

Different types of valve plug have different flow characteristics. This section gives you a thorough understanding of the three main types (fast opening, linear, and equal percentage), and using detailed case studies, how the flowrates are calculated.
Control Valve Actuators and Positioners

This section looks at how actuators enable valves to work, the differences between pneumatic and electric versions, how reverse acting and direct acting actuators work, and why positioners are sometimes also essential for safe and accurate control.
Controllers and Sensors

What they are, when to use them, and the many variations available. We also look at advanced control systems using the HART protocol and fieldbus standards.

Self-acting Temperature Controls

The differences between vapour tension systems and liquid-filled systems are explained, with animated illustrations showing how different options work. We also look at where and why self-actuating temperature controls are used.
Typical Self-acting Temperature Control Valves and Systems

These systems are a vital safety feature. They operate by either adjustment at a sensor, an actuator, or by remote operation. We also examine high limit cut-out devices and the many environments where they are used.
Self-acting Pressure Controls and Applications

Usually used to reduce the amount of steam pressure in a system, self-acting pressure controls tend to be either direct acting or pilot operated. This section illustrates both, looking at choices that determine where each would be used. We also look at pressure maintaining valves, and why these are sometimes needed.

Pressure Control Applications

In this comprehensive review of the methods used to control steam pressure, we look at the advantages and disadvantages of each, the situations where they are usually employed, and important points to note. We also touch upon alternative methods sometimes used.
Temperature Control Applications

When it is the temperature that must be controlled, there are five main methods for doing so. Here we look at their advantages and disadvantages, and where they are usually used. We also survey some of the other options for controlling steam temperature.
Level Control Applications

An overview of the different types of level control systems used, with particular focus on float and solid probe types, most commonly used in the steam and condensate loop. There is a focus on conductivity and capacitance level controls.
Control Installations

How and where your control system is installed with have a marked effect on its accuracy and lifetime. Here we look at the factors to consider to ensure it works at its best for as long as possible.

Safety Valves

Safety valves are essential devices used to protect from steam overpressure. Here we look at how this might happen, the range of types available, how they work, and the regulatory frameworks for them.
Types of Safety Valve

Discover in detail the many variations of safety valves, how they operate (including equations illustrating the force needed to do so), and diagrams of each type of valve.
Safety Valve Selection

Including the criteria you will need to consider, how safety valves are properly installed, and where, and the difference between MAWP and MAAP.
Safety Valve Sizing

A detailed look at how to size valves according to various standards, with diagrams and equations for each case. We also look at more complicated solutions like two-phase flow and superheat.
Safety Valve Installation

For it to work correctly, it's vital you know all the factors to make the right decision. Everything you need to know is covered here.
Alternative Plant Protection Devices and Terminology

They might be the most effective, but safety valves are not the only way you can deal with excess pressure. This section looks at the alternatives and gives a full glossary of terms related to this topic.

Introduction to Steam Distribution

Here we examine what is the steam and condensate loop, the working pressure of a system, and see why pressure-reducing valves are used.
Pipes and Pipe Sizing

Covering the international standards, schedule numbers, piping materials, and detailed information on the equations, charts, and tables needed to pick the correct piping. Includes comprehensive appendices.
Steam Mains and Drainage

We look at the overall layout, condensate drain points, using branch lines, steam separators and strainers, how to calculate your running load, and what to look out for to avoid waterhammer.
Pipe Expansion and Support

Because they are carrying hot fluids or steam, allowance must be made for expansion. Here we cover the various methods of making sure your pipes are properly installed.
Air Venting Heat Losses and a Summary of Various Pipe Related Standards

How to effectively remove air and noncondensable gases from a steam system, and how to calculate, and reduce, heat losses from pipework. Includes relevant international standards covering the subject.

Introduction - Why Steam Traps?

The main job of a steam trap is to remove condensate, air, and any noncondensable gases from a steam system whilst minimising the escape of live steam. Here we look at why this is necessary, how they do this, their basic operation, and the standards applied to steam traps.
Thermostatic Steam Traps

These work by responding to the surrounding steam temperature. There are three main types: liquid expansion traps, bimetallic traps, and balanced pressure traps. We look at each, with animated diagrams showing how they work, and the pros and cons of each.
Mechanical Steam Traps

These use the different densities between steam and water (condensate) to operate. There are two main types: the ball float trap, and the inverted bucket trap. Able to remove large volumes of condensate, mechanical steam traps are used in a wide range of process applications. Discover how each works, and their advantages and disadvantages.
Thermodynamic Steam Traps

It is a very robust form of trap, with only one moving part, that operates using the dynamic effect of flash steam as it passes through the trap. We examine the traditional thermodynamic steam trap, the impulse type, the labyrinth type, and finally fixed orifice traps. How they're made, their uses and pros and cons are discussed.
Considerations for Selecting Steam Traps

Other things to take into account when choosing steam traps: waterhammer, dirt, strainers, steam locking, group trapping, diffusers, and special needs, like vacuum drainage and trapping for temperature-controlled processes.
Selecting Steam Traps - Canteen Equipment Oil Transfer Storage Hospital Equipment

Giving tables and advice on picking the right options for these uses, from boiling pans to bulk storage tanks, to autoclaves and sterilisers.
Selecting Steam Traps - Industrial Dryers

Advice on choosing traps for hot air dryers, drying coils, multi-bank pipe dryers, drying cylinders, and multi-cylinder dryers.
Selecting Steam Traps - Laundries and Presses

Looking at the right steam traps for garment presses, ironers and calenders, tumble dryers, dry cleaning machines, and various types of presses, including tyre presses.
Selecting Steam Traps - Process Equipment

Advice on the ideal steam traps for fixed and tilting boiling pans, retorts, industrial autoclaves, industrial digesters, hot tables, brewing coppers, evaporators, and vulcanisers.
Selecting Steam Traps - Space Heating Equipment

Best and acceptable alternative choices of steam traps for calorifiers, heater batteries, radiant panels and strips, radiators and convection cabinets, unit heaters and air batteries, and overhead pipe coils.
Selecting Steam Traps - Steam Mains Tanks and Vats Pressure Reducing Valves

Covering aspects of the steam mains operations, including horizontal runs, drain pocket dimensions, separators, steam header drainage, and terminal ends. We also look at process vats and small coil-heated tanks.
Air Venting Theory

Because air is an insulator, it works against the efficient heat transfer of a steam system. This section looks at how to detect air in the system, and how to remove it effectively.
Air Venting Applications

Examining many of the cases where air venting will be needed, including the steam mains, jacketed pans, and rotating cylinders. We also consider the use of steam trap bypasses, and how thermostatic steam traps can also be used as air vents.
Testing and Maintenance of Steam Traps

Examining routine maintenance, replacement of internal parts, and potentially replacing steam traps. However, accurately identifying issues with steam traps requires expert knowledge, and we look at manual, remote, and automatic monitoring to determine if there actually is a problem.
Energy Losses in Steam Traps

Often steam traps are blamed for energy losses simply to gain a new sale for an alternative. This section honestly looks at the three types of main steam trap and demonstrates just how little energy steam traps use. trap types.

Isolation Valves - Linear Movement

Used to stop the flow of fluid into an area of the system, we look at the different types of gate valves, globe valves, piston valves, and diaphragm valves. We also look at options for valve stems, and how to seal them.
Isolation Valves - Rotary Movement

Sometimes known as quarter-turn valves, we delve into ball valves and their various options, and butterfly valves. This section also gives details on selecting isolation valves, including their sizing, with comprehensive charts and the equations for getting to the right choice.
Check Valves

Also known as non-return valves, a check valve will only allow flow in one direction. The main types used for steam are lift, swing, wafer, and disc check valves. Ball and diaphragm check valves are usually used in fluid applications. Formulae for calculating pressure drops are also given.
Strainers

Usually classified as either Y-type or basket type, strainers prevent damage from debris in flowing liquids or gases, so reducing plant downtime and unplanned maintenance costs. Here we take a detailed look at the options, and how to select the right size, depending upon your processes.
Separators

Important tools in reducing 'wet steam', separators come in various forms. We look at baffle, cyclonic, and coalescence separators, detailing which option to choose, and how to calculate the dryness fraction.
Gauges Sight Glasses Vacuum Breakers

Though relatively small in size, these play a big part in the smooth running of energy-efficient steam systems. We examine what each does, and how they work.

Heat Exchangers And Stall

Investigating how to remove condensate from heat exchangers fitted with a temperature control valve on the steam line, and a steam trapping device on the condensate line from the heat exchanger.
The Heat Load Heat Exchanger and Steam Load Relationship

The equations needed to determine the design loads and steam pressure and flowrate requirements for heat exchange applications.
Oversized Heat Exchangers

Often heat exchangers are bigger than needed for the job they need to do. This section looks at the implications of this, the effects on issues like selecting the right steam traps for them, and details the equations needed to deal correctly with this common problem.
Example Selecting The Trap

Step-by-step illustration for calculating stall and how to select the right condensate removal solution for a heat exchange application.
The Stall Chart - Constant Flow Secondary - Constant Inlet Temperature - Varying Outlet Temperature

Using this simple method, stall can be worked out for an situation with a constant secondary flowrate with a varying inlet temperature.
The Stall Chart - Varying Flow Secondary - Constant Inlet Temperature - Constant Outlet Temperature

Sometimes constant secondary flow is not required, such as providing hot water to batch processes like tank or vats. This example shows how to use the chart in these cases.
The Stall Chart - Constant Flow Secondary - Varying Inlet Temperature - Constant Outlet Temperature

In cases where constant flow is secondary, there is varying inlet temperature, and constant outlet temperature.
Practical Methods of Preventing Stall

Methods of dealing with condensate drainage problems include gravity drainage, adding an automatic pump trap device, and controlling the pressure in the steam space.

Introduction to Condensate Recovery

Why condensate recovery and return are useful, saving energy costs, reducing environmental discharges, and keeping water treatment costs down. Covers calculations for potential savings.
Layout of Condensate Return Lines

A fully-illustrated, detailed look at the design and layout of condensate return pipework. This includes the effect of trap types used, how different pressures impact the system, and the discharge of condensate into flooded mains.
Sizing Condensate Return Lines

How to size condensate lines to and from steam traps, with examples and formulae needed using the condensate pipe sizing chart.
Pumping Condensate from Vented Receivers

This comprehensive introduction covers pumping terminology, the operation, application and various benefits of electric centrifugal and mechanical condensate pumps. There are sizing examples for both pumps and pump discharge lines.
Flash Steam

What is flash steam, how much is available, how it can be recovered, controlling flash steam, and its applications.
Lifting Condensate and Contaminated Condensate

Here we look at moving condensate to a higher level return line, and ways to cope with contaminated condensate.

Basic Desuperheater Types

First we cover the issues to think about when selecting a desuperheater, such as turndown ratio. Then we survey the types of desuperheater available, including indirect contact, direct contact, water spray, and axial injection desuperheaters. Consideration of the advantages and disadvantages of each is offered.
Basic Desuperheating Theory

The difference between superheated and desuperheated steam is detailed, where both types of steam are typically used, and calculations for desuperheating.
Other Types of Desuperheater

A range of other desuperheaters are commonly used. Here we look at venturi type, steam atomising, variable orifice, combined pressure control valve and desuperheater, and compare the options alongside one another.
Typical Installations

There are a range of factors that must be considered. This section looks at key issues, including the properties of the cooling water itself, the installation of the desuperheater, pressure control, and sensor positioning.

Steam Insights

Introduction

Steam engineering principles & heat transfer

The boiler house

Flowmetering

Basic control theory

Control hardware: Electric/pneumatic actuation

Control hardware: self-acting actuation

Control applications

Safety valves

Steam distribution

Steam traps and steam trapping

Pipeline ancillaries

Condensate removal

Condensate recovery

Desuperheating