Pressure Vessel alterations and safety

[ed72073]

Ok I have attached a photo for everyone to look at and hopefully I can explain what it is I am asking. In the photo there is a pressure vessel that is used with sandblasting that comes certified from a manufacturer. Afterwards there is a flange or ring that is welded to the head pipe to allow a cone to be bolt to the pressure vessel for media storage, mind you this is done by a non code shop and never certified after the alteration.

What I am being told is because the cone is not under pressure this is considered to be safe and not required to be tested and still falls into the original testing and certifications. Yes there is usually no pressure inside the cone are unless the valve breaks or is worn, but even if there never is any pressure in the cone, there is pressure under the head pipe which is where the flange is welded to, which is also directly under the cone. My concern is the welding of the flange to the head pipe caused fatigue and stresses to the pressure vessel and now needs to be tested over and certified to be safe. I also feel that the alteration being done by a non code shop is another reason to not use the pressure vessel

The company did provide documents from when the pressure vessel was designed and tested to be safe, but they could not provide anything afterwards because nothing was submitted to the National Board about the alteration.

Does the explanation of there being no pressure inside the cone and is considered safe sound correct? To me and others this is absolutely crazy. It is like saying it will only effect the inside of the pressure vessel and not the outside.

 

[metengr]

What does the internal view look like? I recall hearing about this at a National Board Chief's meeting but I don't believe anything more came about. The Code does not specifically address a leaking valve, this is up to the hazard analysis performed by the designer or user of the vessel. I would need more information before saying yes or no to your question.

 

[ed72073]

I have loaded another photo with some description of what I am trying to explain, hope I explained it for you to understand. The valve is not the main concern, but will cause an issue if it was to fail or break. The main concern is the area of where the flange has been welded to the pressure vessel, as well the procedure. I have been getting a lot of information from a local Illinois inspector, and he did send out a email to all state inspectors about this concern, so it may have been talked about during the National Board Chief's meeting, as I know he was at one recently.