Rigging off of Pressure Piping

[dugal]

Hi all,
We always have problems with our mechanics rigging off of system piping to help remove equipment. We tell them if they want to do this they should contact design engineering to do a pipe stress analysis first. This prompts them to rather look for another rigging point or tooling.
However, sometimes it is the only way. I have seen procedures where you must first drain the pipe, check hanger spacing and loads, etc.
Anyone heard or seen procedures on this or code rulings that this must not be done ?
Thanks

 

[TBP]

It really shouldn't happen, but in most private sector general industrial operations, it's very common. You never get the resources to install proper structural arrangements to get pumps out of pits, etc. "Oh, we'll leave room to get a fork lift in there for pump maintenance." 6 months later there's a big, new piece of machinery sitting across the lift truck access. Or, if it CAN be hit by a fork lift, sooner or later, it will be.

In most plants, it's unlikely that this practice will stop. You just have to allow for it by installing the hangers closer together, and/or doing things like going to pipe with a heavier wall in locations where people are probably going to hang their chainfalls from it.

 

[dugal]

I can tell you have been around TBP. There is a real art to designing "maintainability" into a facility. I have never seen a book or course on the subject but if there are some they are well buried.
If you told a labor inspector and pressure vessel regulator of the goings on they would flip.