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Correct Installation of Steam Traps

Importance of Correct Installation of Steam Traps

Correct installation of steam traps is as crucial as correct selection of steam traps. Many times, it has been observed that correctly selected steam traps often fail due to wrong installation.

Installation of steam traps is often not given as much of importance as the steam trap selection which results in lowered operational life of steam traps.

While installing a steam trap, some points should always be remembered. Every steam trap should have a strainer fitted before it. In case of thermodynamic steam traps or bucket traps, an inbuilt strainer is present which eliminates the need of installing a separate strainer. On the other hand, float type steam traps do not have an inbuilt strainer and hence, it is imperative to install a strainer upstream to avoid blockages and damages to the trap internals.

Similarly, provision to bypass the steam trap for quick maintenance is a must. If the steam trap is discharging against some back pressure, a non-return valve (disc check valve) should be installed downstream of the steam trap to avoid the water logging due to negative pressure difference across the steam trap.

Wrong Installation of Steam Traps might result in –

  1. Water logging in the process equipment or mainline if the trap is unable to discharge condensate
  2. Water hammer
  3. Damage to the steam trap and its internals.
  4. Reduced operational life of the steam trap and increased steam consumption

This article explains the correct installation procedure for different types of steam traps.

Correct Installation of Thermodynamic Steam Traps

  1. Check materials, pressure and temperature and their maximum values.
  2. Before installation, flush the inlet drip leg to remove all dirt and oil. Ensure to remove all protective seals from the trap.
  3. The Thermodynamic Trap should be installed in a horizontal plane such that disc movement happens only in vertically up and down directions.
  4. The horizontal mainline should be provided with proper collecting pocket as provided by equal Tee should end with a drip leg and at the end of the drip leg Thermodynamic Trap should be fitted. Typically recommended drain pocket dimensions relative to steam main pipe sizes are given below.

Note: Condensate should not be drained through a small pipe connection at the bottom of mainline.

Correct Installation of Single Orifice Float Traps (Float type traps)

  1. Check the correct installation location/position and the direction of fluid flow.
  2. Remove protective covers from all connections where appropriate, before installation.
  3. Ensure the availability of all components as shown in Figure 5, to ensure the operation of the trap.
  4. If the trap is to discharge to atmosphere ensure it is to a safe place, the discharging fluid may be at a temperature of 100 °C (212°F).
  5. Install the trap such that the arrow on the name plate points downward to achieve proper orientation of the trap.
  6. The arrow on the casting should be in the direction of the flow.

Correct Installation of Balanced Pressure Thermostatic Steam Traps (Tracer Line Traps/Air Vents)

  1. Before installing the Tracer Line Trap/Air Vent, flush the inlet piping to remove all dirt and oil.
  2. Remove protective covers from all connections where appropriate, before installation.
  3. The Tracer Line Trap/Air Vent should be installed on horizontal plane and the cover at the top, preferably with a drip leg immediately preceding the steam trap when installed on tracer line.
  4. It is recommended that a non-return valve is fitted when discharging condensate into return lines where backpressure is experienced. It is also recommended that a diffuser is fitted when discharging to atmosphere.
  5. Suitable isolation valves must be installed to allow for safe maintenance and steam trap replacement.
  6. Open isolation valves slowly until normal operating conditions are achieved. Check for leaks and correct operation.