Deflection of plastic pipe

[Kevin Chiu]

Hello everyone, I would like to ask about deflection limits for plastic piping.

I have a project where I used pipe stress analysis software to evaluate the stresses in a PPH pipe with a diameter of d160.

The simulation results show that the utilization is within the allowable limits. However, the calculated deflection is slightly higher than the DVS guideline (15 mm > 5 mm (L/150) ).

May I ask, if the stresses are acceptable but the deflection does not meet the guideline, what kinds of problems could this cause? Thank you for your feedback.

 

[GD2]

You need to evaluate what implication it will have by the process fluid on the piping. Where isolation and draining/ventings are required for maintenance and repair work, will it be safe to work? Think about a toxic material the piping is carrying. You may also encounter issues with gravity flow lines.
Talk to the process and take their opinion. It all comes down to safety.

 

[KevinNZ]

I have not seen a defection limit in any pipping code, just stress limits. Has DVS just made this up to be conservative?