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

Mr. Dan, could you pls reply to the above question.

Need to show us a sketch.

Meanwhile....

Your 149 deg C sould like is about steam out temperature so a WNC load case at this temperature is required if your line is not gas line.

From your description, a spring can is not required.

The purpose of the tracing is to keep the line warm so probably you will not have problems with the by-pass line. But the 327 deg C design temperature of the steam line mean that you have to take a look also at this line to see if is flexible enough (visual check).

Read also:

http://www.cheresources.com/steam_tracing.shtml

http://www.steamonline.com/tracing.html

Regards,

Please find attached file, which is self explanatory

The service is gas, steam tracing is only for the control loop arrangement, and except the control loop arrangement and a tapping all other piping system is existing. Piping system comes from a knock out drum and connects to a flare stack via this control loop and a tapping is taken before this.

Thanks for the material and explanation. It is very useful.

Not the very best layout, but....

Try to have the same length for the trunnions on the large lines (I guess that you insert some temperature on the trunnions that it is not really required), use the gaps on guides and stops, see if this will make the line to rest on the +y support. If not, use Y.

Regards,

hmmm. The temp. for the trunnions are taken as 21 deg. C, as you can see the first large dia loop piping rests very well, this and above near by piping supports cause the adjacent loops to lift slightly. I used Y supports and absorbed there are no significant changes in stress and loads at the trunnion supports as well as near to the nozzle. So, it is not necessary to provide springs on the two trunnion supports. is it Mr. dan ?

My opinion is that springs are not required. Try to make the length the same for both, use the normal gaps 2..3 mm as per your standard. It should rest on that trunnion.

Yeah, once again Thank you very much Mr. Dan.

Welcome