Hello,

I have some confusion over manufacturing of internal parts. Suppose a vessel is made as per ASME Sec VIII div 1 as the design standard and PED 97/23/EC (Cat III or IV).

1. Can internal parts (gratings to hold catayst) be made from locally available materials (and not those specified in the ASME Code).

2. do internal parts have to satisfy impact testing requirements?

3. Can welding of these internal parts be subcontracted to vendors having non-qualified welders?

1. Internals are non pressure components however some of the internal components take a lot of loads such as gratings to hold catalyst. Since these are non pressure components, material of construction can be different than those included in ASME. I assume that MOC for internals shall be at least stainless steel even though the grade may not be listed in ASME.

2. Welded internals if made of CS to have the same properties as of the parent material. If made of SS, impact testing will not be an issue.

3. Even though the non pressure components (internals) are not in included in ASME, welding by non-qualified welders are not recommended.

Regards

Basic is Internals are mainly design from Chemical process requirement.
And it is Non pressure component.

So ASME Listed or not listed is diff thing as far as process is concern.
You must use as process person define.
-Internal parts does not req. to sarisfy Impact test requirement

-Internal parts have normally very few welds but surely Not allowed to unqualified welders.

_________________
Niraj

Sharjeel,
If a vessel is subject to acceptance by an NB, ask your NB whether their interpretation is in line with your intent. My view is when you use Sec VIII-1 as a design code to satisfy PED, you have to follow all technical requirements of SecVIII-1. AI witnessing and U stamping is not a technical requirement (does not affect either design nor manufacturing). But you have to follow requirements pertaining to welding personnel/processes qualification and materials. If SecVIII-1 says that a non-pessurised part welded to pressure part has to be of good weldable quality and you should prove it either by using allowed material specification or by positive qualification- just follow it. Sure, nonpressure to nonpressure welds are not provided for, so it can come from outside as a ready made weldment, but welding it to your walls has to be done by qualified welders. Thi is to satisfy SecVIII-1 requirements. If you have more (e.g. contractual)- probably they will be more stringent.
Regards

_________________
Konrad Anikiel

Thank you very much.

Niraj, Sanjeev and Akonrad. I really appreciate it.

if the internal parts are not subject to pressure,the material of these parts need't to meet the requirements of the ASME code viii DIVISION i,BUT THE MATERIAL must BE WELDABILITY.

pressure parts and nonpressure parts weld each other ,if full automation weld be used ,the operator s be allowed non-qualified.if manual weld be used,the welder shouold be qualified .