Minimum required thickness VS Sandblast

[hcjulien]

Hi,

Is there any API/ASME/CSA/BS standard or other references specifying the exact minimum required thickness rules for pressure vessel and piping to be able to resist safely to stress caused by sandblast when the equipment is still alive?

Thanks in advance

 

[racookpe1978]

Hmmmn?

Properly done on metal that is itself not rusted and pitted, "sandblasting" should not scour the metal away, but should only remove the coating (outside or topcoat layer, primer, and any undercoats).

Granted, using the wrong material (blast grit instead of pecan or softer material) at too high a pressure or at too close a nozzle-tip distance held perpendicular to the surface "might" create scour zones, but I've never seen it on conventional steel in any naval hulls (blasted in drydock) or on pressure vessels done in power plants.

The greater "thinning" threat that I have seen from area surface corrosion (outside and inside), localized pitting that is exposed by sandblasting - but NOT caused by the sandblasting! - surface-to-surface wear and fretting, cavitation, flow erosion and scouring, chemical corrosion from the carried fluid.

 

[unclesyd]

In agreement with the post by racookpe1978, but would like to add one thing. Contrary to popular belief there is some skill required in blasting, so you just can't grab anyone hanging on the fence and give them a blast nozzle and turn them loose. You need to make sure that you have a competent person doing your blasting.