Process Line and Equipment Demolition 1

[BobW2]

Piping Removal. Has anyone created a procedure for the safe removal of process piping and equipment. Addressing tag out lock out procedures, supervision, general guidlines?

 

[JOM]

Bob,

There's been some tragedies arising from piping removal.

The usual story is people assume lengths of piping are hydrocarbon free, but they do not prove it, just assume.

Cutting the pipe leads to fire in very awkward places, like scaffolds at height.

There was a case where the piping had been decommissioned for years, but still held inflammable liquid when it was removed and caught fire.



Cheers,
John.

 

[unclesyd]

Small demolitions of process equipment are accomplished by the on-site construction and maintenance contractor.
Most of the steel and concrete demolition work is then contracted out to speciality contractors.

We accomplished a lot of demolition of older larger processes over the years and learned some very expensive lessons.
First of all most large demolitions are done by speciality contractors. Our experience is that they are very difficult to work with in the terms of safety (all), their motto is "time is money".

If you have older equipment asbestos plays a big part. A small piece of lagging use on steam tracing costs the company a $50,000 fine plus the fact that the remaining concrete rubble had to be canned and handled as waste and not used a fill.

We keep all maintenance and operational procedures in place up to start of demolition. We tag and lock out the area for demolition. We do the cleanup and lockout as if we were going to do maintenance on the area. Our maintenance personnel follow all breaking and entering procedures on the process piping in opening up to verify the cleanliness. We open up as many flanges or vessels that we deem necessary to insure that all process material has been removed.

Then comes the isolation or the area.
If it's a building or unit our maintenance personnel physically isolate, no tags or chains, the building or unit. The isolation procedure has to be signed off by the Area Supervisor. There is a walk through by all plant personnel concerned, production, safety, fire, and contract management, and others. All questions have to be resolved prior to commencing the demolition work.

The demolition contractor's crew are given a general plant safety rule overview and his supervisory people a little more in-depth review of our rules and we of theirs.
We have a construction follower at the demolition site at all times and they have to authority control the work as they see fit. His main concern is safety and control of any possible environmental concerns . We also have a person from the laboratory that monitors for chemical emissions and runs hot work permits the first couple of days.

The fire department has charged line/lines setup at strategic points and keeps a fireman at the site while work is going on.

The safety and industrial hygiene departments do periodic checks.

The biggest problem we have are the normal safety rules and not getting permits prior to commencing work, like hot work after a long duration fire alarm. I think every contractor we have used has got us in trouble with a regulatory agency, mostly by arguing.

Our process for demolition was long and complex. Every job we learned more to saved more on the next job. It is very hard to cover everything on paper so a good construction follower easily pays their salary. Don’t turn a demolition contractor loose.

 

[Phil100]

You definitely need to ensure that thorough preparation work has been carried out to identify and mark lines for demolition from those to remain; protect services such as P&C cables, comms cables etc; decontaminate lines to be removed; cordon off the area; document a risk assessment; ensure adequate safety precautions, ppe etc; check for asbestos...in the UK HSE requires an intrusive sample and test for asbestos unless you have documentation to prove that it definitely is not asbestos!
In the final analysis consider cold cutting as an alternative to burning if in any doubts as to the state of the internal surfaces. There have been some pretty spectacular bangs from residues being heated and emitting flammable fumes when n one were detected cold!

If in doubt engage a professional to manage the demolition for you!