DECISION ON CODE TO USE PD500 VS ASME 3

[babashitu]

Hello,

Could somebody help explain to me when to use PD5500 or ASME 8 DIV 1 to design a vessel. Is it a project Decision or there are some guidelines for chosing any of the code?

Regards,

Shitu Abdulkadir

 

[corus]

ASME is american, PD5500 is British (it follows on from BS5500). It depends on who your customer is and what they prefer. If they're european, then you'd need EN13445 which harmonised all european codes. Other countries that don't have their own design standards would probably be quite happy for either design standard to apply, I guess.

 

[JStephen]

If there are no other considerations, it would be advantageous to use the same code used on the rest of the facility, the code most familiar to the fabricator, designer, etc.

 

[payaam2000]

Vessel major component thickness which is calculated by Div. 1 is more than the thickness calculated using PD5500 (&Div.2).In most of specifications it is stated that if thickness of the vessel is more than 50 mm, then the vessel fabrication code shall be as per PD5500 or Div.2
Basically safety factor of PD5500 (&Div.2)is 2.4 but safety factor of Div.1 is 3.5
But the quality control of PD5500 (&Div2) is more stringent than Div.1
Before 2007 div2 safety factor was 3 but now safety factor of Div.2 is 2.4 (like pd5500).
If you fabricate a vessel as per Div.1 the weight of vessel and consumables for welding is more expensive than the same items in PD5500 (&Div.2) but QC expenses is less.
It sould be noted some materials are not allowed in DIv.2 but they can be used in Div.1
Some times the thickness is less than 50 mm but since the vessel has cyclic loads(or vessel is critical) it is instructed to use PD5500 (or Div.2) for fabricating the vessel. Because Div 1 has no concern on such loadings.
In my opinion the compare between Div.1 & PD5500 is not basically true because they belong to 2 different classes. By this way PD5500 should be compared with Div.2 .