Steam systems are often oversized, resulting in reduced efficiency and higher energy costs that frequently go unnoticed. By learning how to calculate the actual process steam demand and using smarter equipment such as Venturi orifice steam traps, system losses can be minimised.
Steam is an essential energy medium in many industrial processes. It offers excellent heat transfer capabilities and is non-toxic. However, it is also one of the most difficult media to measure accurately and can therefore lead to hidden costs. Due to its unique properties, steam exists both as a liquid (condensate) and a gas, depending on the stage of the cycle.
Measuring equipment designed for steam systems must therefore cope with changing conditions, which makes measurement not only expensive and technically complex but also prone to inaccuracy and failure. As a result, very few steam systems are equipped with reliable steam measurement technology. Because of this, most operators of steam systems do not have a clear idea of the actual cost and efficiency of the steam they use.
Calculating Steam Costs: Back to Basics
To identify real savings potential in your steam system, start by determining how much steam your process actually requires — that is, how much energy is needed to heat your product to the desired temperature.
Beyond demand, it’s essential to evaluate a steam system’s thermal performance, i.e. how efficiently steam transfers heat to the product. Common losses arise from poor insulation, leaking mechanical traps and oversized or underloaded equipment.
Additionally, the energy required for startup is frequently underestimated, though it can be substantial. Heating equipment, venting air and managing thermal expansion can consume a large percentage of initial steam usage, especially in batch operations. Reducing startup energy is possible through pre-insulation, staged startups, automated venting and proper condensate removal through the use of Venturi orifice steam traps, which, in addition to other benefits, can reduce water hammer – a phenomenon often occurring during startup with mechanical traps.
Questions on how to size steam systems are grounded in basic thermodynamic principles. They can be resolved by considering some fundamental factors:
- The maximum system pressure (main steam line pressure minus any back pressure)
- What do you want to heat? (Is it water, oil, or a viscous fluid?)
- How is it heated? (plate heat exchanger, tube hxc, tanks, kettle?)
- What is the target temperature?
- Time – how long do we need to heat it for?
In other words, you need to know the differential pressure, the product’s mass, its specific heat capacity, the required temperature increase and the time needed for heating. Understanding these parameters allows you to determine the actual thermal demand – often significantly lower than what the current system is designed for. In fact, many steam systems are massively oversized, leading to unnecessary energy consumption and cost.
Oversized and Failing Mechanical Traps
The sizing of steam plant equipment usually falls outside the range of plant operators. Sizing is the preserve of consulting companies or equipment suppliers. Best practice dictates ample safety factors in design. As a consequence, mechanical traps are also notoriously oversized, operating far below their optimal range — sometimes at just 10% of capacity. These inefficiencies often go unnoticed, masked by the belief that “as long as the plant runs, everything is fine”. Unfortunately, most trap assessments rely on simple “pass/fail” evaluations, offering little insight into actual energy performance.
One of the most practical methods for comparing steam trap performance is the so-called “bucket test”. This involves venting condensate into a container under atmospheric conditions and measuring the volume and temperature over time. However, this method is only suitable for low-pressure, low-flow applications and is not possible to perform on process applications.
Numerous field trials and independent tests have shown that there is a simple way to improve a steam system’s efficiency: by switching to ECOFLOW Venturi orifice steam traps. Compared to oversized and unreliable mechanical traps, they offer an energy-efficient and maintenance-free alternative. Their continuous discharge based on the density difference between steam and condensate ensures effective operation across a wide range of conditions—with no moving parts, minimal wear and no risk of failing open. Unlike mechanical traps, which often struggle under fluctuating process conditions such as a high startup load, varying steam pressure or heat load, ECOFLOW Venturi steam traps are designed to operate efficiently across a wide range of condensate loads. Independent studies confirm energy savings of 10–30% when switching from mechanical to Venturi orifice traps—without sacrificing reliability or requiring complex control systems.
It’s a simple, physics-based approach to smarter steam usage — and a key step toward uncovering the hidden savings in your plant.
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