Calling All Power Plant Engineers

After blow down, if vents are not opened, the boiler cooling would create a vacuum inside the boiler, then later on when somebody removed an manhole door for inspection they would be drawn into the boiler, being severely injured if not killed.

Regards JD.

kindly give correct answer

And what is the correct answer, I would also like to know.

Regards JD.

Hi eswararoy,

I believed you are employed and working at Engineering and Maintenance department of one big hotel or establishment as noticed you also have posted about reverse power on turbo generator, if I'm correct then we're both the same.

Usually our machineries are supplied and installed and up to handover equipt with safety, operation and parts manuals which is not only very essential, but must be a requirements. most of the issue are there, however in some reason it was not available you can instantly google it and if you find you are not so satisfied or not so clear or some curiosity on the result then we can ask for more detail answer from the the member which are well verse on the topic you posted.

My point is as in Engineering and Maintenance Department, Safety Operation and Parts manual is a must, this serve as the holy bible of our maintenance staff to guide them the proper handling, repair and maintenance etc. in accordance with manufacturer standard. Happy new!!!

Kind regards

Roman

Failing to open the air vents means the two drums did not empty quickly, having to wait for air to bubble up through the tubes. This slow emptying may leave 'mud' in the drums.

It will not cause any mechanical damage since the vessels are much stronger than required to withstand full vacuum. (Typically, design for 50PSIG will result in full vacuum capability)

hallo.

If u forget to open the vent of super heater and drum during boiler cooling then vaccum will create inside the drum and tubes, which will cause the shrinkage of drum and tubes.

Hi Umeshgupta,

Your answer contradict on Kieth E Bowers, however on my opinion as although i never experience on my boiler, otherwise my Boiler attendant will be reprimanded as this should considered as negligence,I understand that this was taken into account during the design stage, that at any instance the attendant can forget to open the vent of super heater and drum, I believed that if this will give sudden effect to the unit in the event of negligence, then they already supposedly fitted some sorts of safety device . So I should agree with Kieth that the vessel are much stronger than required to withstand full vacuum.(if I'm not mistaken 1.5 higher than design operating pressure minimum). this is safety design consideration. although if the situation becomes a common practice of the boiler attendant, I would say there will be a bad effect on the unit of course, try your car keep on over heating 4 times a day due to the continual neglect of your driver, I don't think your car will last for 1 month. in short, Kieth and you got some point.

Kind regards

Roman

You will draw a vacuum and damage the boiler and drums. If you pull a good vacuum you may find the "stays" punching thru the drum. A boiler is designed to contain pressure. Pulling a vacuum creates forces that are opposite to its design. I have seen pressure vessels crushed like a soda can after pulling a vacuum.