Rising gas prices and a need to cut CO2 emissions has led to
an increasing focus on the efficiency of steam plant.While
there are many ways to boost efficiency, often they involve
considerable investment. Before embarking on any large
capital project,TLV Euro Engineering recommends a closer
look at the system itself using five, relatively easy steps

It is always useful to get an idea of the cost
of steam generation. All the calculations
quoted here are based on a plant running
24/7 for 50 weeks a year. For the best results
you need to attain the steam cost for your
site. Approximate steam costs can be
calculated easily by taking the fuel costs and
calorific value and applying a
rough figure for boiler
efficiency. For a more accurate
approach the amount of
steam generated, fuel costs,
water costs, water treatment
costs and also boiler
maintenance costs can be
taken into account.

Steam trap testing
A steam trap survey can
easily identify leaking or
faulty traps and provide
significant potential
savings. For example, it is
not unusual for a site with
100 steam traps to find 15 to
20 are leaking. A leaking steam trap could be
losing you up to £2000 per year, so the
potential annual loss – and therefore the
potential saving – is in the region of £35,000.

Replacing the traps could provide payback in
months rather than years. The same survey
will also identify blocked traps, which can
significantly reduce process efficiency, affect
steam quality and impact on the safety of the
system.

Condensate return
As the cost of steam rises with the increase in
energy prices, so does the value of
condensate. Calculating the value of
condensate needs to take into account heat
energy, water charges, the cost of water
treatment and effluent charges. Based on
typical costs of £3 or £4/t, a small steampowered
process discharging 1000L of
unrecovered condensate per hour, would be
costing approximately £24,000 per year. In
contrast, the savings made by the installation
of an efficient condensate return system with
associated pipe modifications, could result in
a payback of less than six months.

Pipe insulation
Although the cost of insulation can be high,
the potential savings can deliver a rapid
return on investment. Programmes are
available to calculate the standing losses from
unlagged steam pipes. All that’s required to
establish a realistic estimate is a simple site
survey to identify the size of pipe and the
steam pressure.

To quote an example of the benefits:10m
of un-lagged internal pipe; a steam pressure
of 10barg; an ambient temperature of 20°C;
and a process running 24/7 can lose as much
as £4500 per year. Simply installing 50mm of
insulation to the 10m pipe length could
reduce the running costs to £400/year.

Steam leaks
A 1mm hole in your steam main could be
costing £500 per year. A 2in isolation valve
with a leak from the stem could be costing
£750 per year. So if you think highlighting
steam leaks is obvious, take a walk around
your steam system and take note of any leaks
from valve stems, safety valves, flanges and
unions. You may be surprised how many you
find.

Steam metering
Steam metering itself will not directly save
energy, but for good housekeeping it is an
essential discipline.Metering from the boiler
house provides accurate steam consumption
statistics for a typical working day, and can
be a useful troubleshooting tool. For example,
a rise in oil consumption without a
corresponding rise in steam production can
point to a problem with the boiler.

Potentially, there are thousands of pounds
worth of savings to be made by following
these five simple steps. For the best results
you may need the help of a steam specialist
company, but elements of a preliminary
audit can be carried out in-house. Based on
the findings, a program of work can be
identified in order to realise some serious
improvements.