Rupture Disk Vent Safety
During a plant final completion punchlist walkdown, the EPR team observed a serious condition with steam rupture disk vent stack locations. The discharge point was face-high at an operator's platform.
These disks relieve pressure from a very large "reservoir" LP header at about 800F and perhaps 250psig. At some prior point, during early operations or commissioning these disks activated. The energy from this release had ripped insulation and metal jacketing from the above cold-reheat piping which was later partially repaired. However, the insulation is still imbedded in structural steel and other equipment in the area from the force of the release.
It is a serious safety concern when a standard design platform for personnel access is above the vent stack. If any personnel would have been located on the platform during this release, they would have no doubt been seriously injured or a possible fatality would have occurred.
Minimal. However, potential Owner risk is significant if a fatality occurs.
In this instance, the facility was combination of power and desalination on a scale that made it one of the largest in the world. It was routine for staff to use vehicles during the normal course of business due to its size.
In many plants fire systems are usually the subject of some scrutiny related to protection from vehicle damage. However, in this facility there was an extensive amount of process piping and dozens or perhaps hundreds of locations where underground piping emerged near roads to interconnect to above ground processes. This piping was glass reinforced plastic (GRP), or fiberglass. While a great material, it is fragile when subjected to impacts.
After a couple instances of non-destructive damage, the issue of protection was evaluated. In this case the piping was designed to ASME B31.3 and with some additional EPC contract language, it became clear bollards or other means of protection needed to be installed.
B31.3 refers to safety inherent in the piping by virtue of the materials of construction, methods of joining, and history of service reliability. Further,... Read more
Some savings, perhaps on the order for $250,000.
For plants where these processes are a material part of revenue, piping damage can take down a whole block for many days. In this instance one block outage (desalination) costs about $350,000/dy.
Piping insulation installation activity unfortunately occurs when crews are under a great deal of pressure to finish. Piping is almost always at or near critical path for any industrial power project. It gets rushed.
While that explanation is a hat tip to reality, it is not an excuse for the extraordinary poor quality exhibited in many new facilities. In these photos, the plants are not more than one year into COD and look 15 years old. Over time, these plants will get worse.
For owners, quick deterioration of piping insulation can cause several problems. Heat loss, safety, and general sense by O&M staff that the plant is not worth maintaining because it certainly doesn’t look like anyone ever cared. Many overlook this point, but O&M culture affects a plant, and a plant delivered in poor condition can also work against new management trying to instill a culture of personal ownership with new crews.
So, what about heat loss. Consider technically, a few inches of open insulation on steam piping allows as much heat loss as maybe a hundred feet of properly insulated pipe (... Read more
None, or perhaps a small savings.
High, though unknowable. Suggest it’s many millions of USD. The cost of thermal drag might be as high over time.
Sometimes good sense isn’t that common.
This is particularly true when it comes to safety gates at the top of access ladders. Contractors in developing regions often have a view that labor is so inexpensive, that making things is cheaper than buying items, especially if sourcing from outside the country.
Unfortunately, this ‘handmade’ product is just not of a suitable quality and the hardware provided for spring closures is equally bad. Keep in mind while viewing the photos, that companies make excellent bolt on plastic arms that last a very long time, work without fail, and are easy to install.
The importance of these items cannot be overstated and where they are absent or not working, an operator can be subjected to a nasty fall that could easily be fatal. OSHA is clear that this is not a small matter, thus the CFR 1910.23 standards that govern installation and use of such devices.
While seemingly minor, for owners that are in the process of developing specifications to attach EPC contracts, it is suggested that you pick a nice quality swing gate and allow the contractor... Read more
None. Probably cost more to fabricate a gate.
This issue is not about cost but prevention of injury and fatalities. Both can have a high financial and moral cost.