Two spring can supports are used in a control loop piping (20”) system, spring cans are selected based on design temp. 149 deg C, but the operating temp. is 65 deg C. A single steam tracing line is at the top of the 20” piping and its operating temp. is 232 deg C & design temp. 327 deg C. Uplift of the two control loops at the elbow is 3 mm and less @ design temp. The uplift is because of a near by first control loop (+Y with guide) support. I replaced the spring support and arrested (+Y and –Y) vertical direction, then I noticed there are no significant changes in stress and loads at the support as well as near to the nozzle.

1. What temperature shall be used to select a suitable spring support for the above condition and normal condition ?

2. Is it necessary to provide a spring can support for 3 mm uplift or it shall be replaced with a Y type of dummy support ?

3. Do I need to care any other additional considerations in a steam tracing piping system ?

Thank you in advance