Dear all,

I have some quite stupid question,

I have large bore routing line connect with column with temperature 20 Degree C, the content is gas with low density.
Nozzle of column is located at the high elevation above ground (approx. 20 m.). I put the spring hanger at the last support before nozzle point (away from Nozzle approx. 5 m. I really can not put it closer).

The solution are spring was automatically selection by program accordance with normal operating temperature. The nozzle load of operating case, design case and sustain case are acceptable. But the problem is nozzle load of WNC case are very large because spring absorbed load only 5% of normal operating condition load then nozzle load are quite large.

I found this problem twice time in 2 systems. But for other are normal.

Please clearified this problem for me.....

Best regards.

One idea to try is to release the restraint at the nozzle node for the hanger design. This will change the hanger design and affect all following load cases, but it may help you out.

pornlert_wana,

I'm having trouble picturing your situation. You say that your fluid is a gas of low density. Typically, gas piping is modeled as an SG of 0 since it usually contributes nothing meaningful in terms of load compared to pipe/insulation/etc.

So, even if you have coded a very low density for your gas, you ought to get almost identical results for a W case and a WNC case.

My first suspicion, from what you've posted so far, is that you incorrectly coded the specific gravity and your spring is being sized to carry more weight than what you have. In the WNC case, the spring is going to act with the same force, but without the weight to resist it, you can end up overloading your equipment nozzle.

What SG have you coded for the gas?