Steam Trap

Steam Trap Basics: Types, Sizing & Selection

In this section, we discuss the following topics regarding steam trap:

A Steam Trap is an automatic valve which holds back steam and only opens to discharge condensate from steam lines. This is important because steam must be kept dry. Wet steam will cause the temperature of the steam to fall and this will affect the critical processes. It can also damage steam equipment such as reducing valves and safety valves. Presence of condensate can also cause water hammer.



Max Min Temperature (°C)






Max Capacity kg/h

Body and Cover Material

Secondary Pressure Range

Type of Trap

Glass O.D / Length

Pipe Size


Steam Traps

Steam Trap


    Improve your steam efficiency with Miyawaki Steam Trap

    Explore our range of steam traps designed to optimize your system’s performance, reduce energy costs, and ensure a seamless operation.

    a. Thermodynamic Steam Trap

    Operates using a disc mechanism, providing reliable condensate removal and contributing to enhanced system efficiency.
    Simple operation and low cost

    b. Thermostatic Steam Trap

    Utilizes temperature-sensitive elements to modulate condensate discharge, ensuring precise control in various steam system conditions.
    Good durability for high pressure applications and superheated steam

    c. Float Trap

    Employs a float mechanism to open and close, efficiently draining condensate and preventing steam loss.
    Good for large condensate loads such as heat exchanger applications

    d. Inverted Bucket Trap

    Features an inverted bucket mechanism that opens and closes with condensate, providing efficient drainage and reliability.
    Good for medium condensate loads

    Sizing & Selection

    PressureBest ChoiceSecond Choice
    Steam Mains< 1,6 MPaTB9GC1, D, S, ES
    < 2,1 MPaTB7GC1, S
    < 6,4 MPaTB51, TB52S61, S62, ESH
    < 19,6 MPaTB71, TB72, TB81, TB82
    TracingSteam Tracer LinesTBD
    Tank HeatingTBD, ES, S
    Copper Tracing (Instrument Tracing)TB1NDC1
    HeaterG, S, ERS
    Heat ExchangerGES, ER
    VaporizerGES, S
    DistillerDES, S
    SterilizerDES, G, S
    Cylinder DryerES, ER
    Band ryerGES, ER, D
    GES, D, S
    VulcanizerDS, ES
    Tyre ressesDS, ES
    AutoclavesDG, ES
    DryerGES, D, S
    TumblerGES, D, S
    PressesDS, ES
    Steam MannequinsDES, S
    Steam IronSL3SD1
    Steam ManglesD, GES, S
    Food Processing
    Process Boiling PansGES, D
    Hot TablesD, GES
    Drying PlatensD, GES
    Jacketes Boiling PansDG, ES, S
    Tilting PansESD
    Brewing PansGES, D
    EvaporatorGES, ER
    RetortsGES, ER
    Heating & Air
    Steam RadiatorWD
    Unit HeatersGES
    ConvectorsWD, ES
    Radiant PanelsWD, ES
    Air HeaterDES,G
    Air HumidifiersES, GD, S
    Heating CoilsD, ESG, S
    Air Conditioning UnitsES, GD
    CalorifiersG, ESD


    The purpose of sizing is to ensure that the discharge capacity can meet the requirements. First of all the steam flow rate must be known. After applying a safety factor of around 2 to 3 times, the required capacity of the steam trap is known.

    Based on the differential pressure (difference inlet and outlet pressure of the steam trap), the maximum capacity of the selected steam trap can be known. The maximum capacity of the steam trap must be higher than the required capacity.

    Where should I install a steam trap?

    Ideally, a steam trap should be installed every 30m to 50m of steam piping. Steam traps should be installed at the lowest point. Not only is this better for good discharge of condensate, it also facilitates the maintenance of the steam traps.

    Avoid group trapping if possible. Always use individual trapping.

    Maintenance through Steam Trap Survey

    An efficient trap wastes less energy. In addition, it also maintains clean and dry steam.

    Under the proper conditions, a steam trap is expected to last around 3 – 5 years. However it can fail prematurely due to:

    • Pipe debris such as pipe rust
    • Steam cuts especially at high pressures
    • Improper orientation during installation

    If a failed steam trap is not replaced, it could lead to issues like water hammer or the process cannot achieve the required temperature.

    Leaking Traps

    The most common issue is leakage of the steam trap. When this happens steam can be seen to be flashing from the steam trap. There could also be small leaks which can only be detected using an ultrasonic vibration detector or thermal imaging.

    Besides being a health hazard, even a small leak could potentially lead to thousands of dollars in energy loss over time. For example, if we take a thermodynamic steam trap at 3 bar steam, the financial loss per year due to leaking steam could look like this:

    These calculations are for one small steam trap. In a large refinery, the number of steam traps could number in the thousands. The financial loss due to leakage of steam has a huge impact on costs and the environment.

    Plugged / Choked Traps

    The trap may fail to discharge condensate properly as the orifice could be choked. Dirt, pipe scale, rust, packing and joint material or debris can cause these blockages. When this happens, the user may observe that the temperature cannot achieve process requirements. In serious cases, the condensate collects at the bottom of the pipe which can result in waterhammer.

    Steam Trap Inspection Survey

    Techmatic performs scheduled steam trap survey to check all the steam traps periodically and ensure that all traps are in proper working conditions. We use the ultrasonic vibration, thermal imaging and stethoscope methods to check for leaks. Based on this data, the steam loss can be calculated using a software.

    If found to be faulty, the trap can be replaced or serviced.