STEAM TRAPS Introduction Steam Trap Selection Guidelines • TRACING Applications
Steam tracing refers to using steam to indirectly elevate the temperature of a product or process by using tubing or some type of jacketing device filled with steam. In a typical steam tracing application, stainless steel or copper tubing is filled with steam and is coiled or wrapped around the outside of a pipe or tank containing material that requires heating. The steam inside the tubing transfers its heat to the material in the pipe or tank; to stop it from freezing or to lower its viscosity to allow it to flow more easily. A steam trap is required for tracing to remove the condensate and air from the system. The most common trap choice for tracing applications is the Thermostatic type. Depending on the particular tracing application, it is often desirable to have some amount of condensate backup in the tubing. Tracing Applications
Steam Tracing Applications:
Primary Trap Choice
Special Notes
Thermostatic traps are suitable for the majority of steam tracing applications; for critical steam tracing applications, where no back-up of condensate can be tolerated, thermodynamic traps should be used.
Typical Service: Some condensate back-up preferable Critical Service: No back-up of condensate permitted
• Thermostatic
• Thermodynamic
Heating Horizontal Pipelines Tubing should not be wrapped around horizontal pipelines or condensate will collect at low points. After shutdown, condensate retained in the system could potentially freeze. Therefore, tracing tubing should be run parallel to any piping and sloped slightly towards the steam trap to promote condensate drainage.
Heating Vertical Pipelines Tubing can be wrapped around
the piping with a steam trap installed at the low point to allow condensate to freely drain by gravity. Partial back-up of condensate using thermostatic trap.
WT2000 Thermostatic (5˚F - 10˚F subcool)
TD600
Thermodynamic Traps
Thermostatic Trap
Bi-Metal Steam Trap with Adjustable Discharge Temperature (WT5000)
For applications where overheating of product fluids in a pipeline may be a concern, an Adjustable Bi-Metal Steam Trap, such as the WT5000 (shown), should be considered. The discharge temperature of the condensate can be manually adjusted to control the amount of condensate back-up in the tracing tubing. This technique can be used to control the temperature of the product in the pipeline.
By increasing subcool, hot condensate can be made to back-up into hundreds of feet into tracing lines if required.
WT5000 Bi-Metal
WT5000
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www.watsonmcdaniel.com •• Pottstown PA • USA • Tel: 610-495-5131
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