2 replies to this topic

[mvancleave]

Does anyone have any references that discuss what quantity/pressure steam could be safely vented indoors? I have a couple of situations where venting outdoors will be very challenging (obviously, if it is necessary for safety, the challenge is irrelevant). I think a case can be made for these to be safely vented indoors, but I lack references to back me up.

These vents would be located inside a relatively large powerhouse, not normally continuously manned (i.e. comfort would not play a major role in the analysis). The powerhouse is roughly 450 ft x 270 ft and is about 90 ft tall.

Specifically, I have two situations. The first is a 15 psi steam relief valve vent (from an air ejector). It would be easy to route this vent to a location that is inaccessible to personnel, but much more challenging to get it outdoors.

The second are the vents for the rupture disks on the condenser. These will be a much lower pressure, but relatively large flow. Again, terminating these lines at a location that is inaccessible from the operating floor and any operating platforms would be fairly easy, but outdoors is very challenging. Obviously, this would be a once (hopefully never) in a lifetime event.

Any thoughts on where I should start?

Thanks,

Mike

[pleckner]

Except for the obvious possible safety issues, which you seem to have considered, I have no problem relieving steam indoors. I hope this is a hearing protection area because if a PSV were to go when someone just happened to be in the vicinity, it will not be pleasant and may even cause a scare! Remember, the noise can make someone jump when it is not expected and that alone could cause an accident.

You might want to check out the OSHA website for any references. Check with your safety people as well. They might have someting to say about this.

[JoeWong]

Mr. Leckner / mvancleave,

Please allow me to add my 2-cents worth comments.

Noise within a close building may be an issue. You have clearly highlighted. General requirement of 85 dBA at nearest location (some consider 105 dBA within short-term exposure) may not be easy to be achieve with PSV located at 90 fts.

Steam cloud accumulated within a confined area may be a safety issue. Steam cloud generation speed compare to action time from operator aware there is PSV discharge and evacuate to the nearest exit needs to be checked. Of course, you can always request operator to have proper PPE which can stands for steam cloud.

You may also needs to check if any issue with the equipments / device expose high temperature steam e.g. some piping painting material may not take steam temperature

I wish the steam system may not contain toxic material. If so, you may need to check proper dispersion of this toxic material within the confined area and how this toxic material is evacuated in the event PSV passing / leaking or relief.


regards,

JoeWong