Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
No, the cat's fate wasn't determined until the box was opened.
No, the cat's fate wasn't determined until the box was opened.
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Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
- Thread starter Terrierbyassociation
- Start date
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
I'll take "Rearranging the Words in a Sentence" for $200, Alex
I'll take "Rearranging the Words in a Sentence" for $200, Alex
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
It's an important distinction. The way you put it, the cat's fate was determined before, but it was only discovered when the box was opened. However, the real Schroedinger's Cat is in an indeterminate state, neither alive nor dead, until the box is opened and it is observed.
It's an important distinction. The way you put it, the cat's fate was determined before, but it was only discovered when the box was opened. However, the real Schroedinger's Cat is in an indeterminate state, neither alive nor dead, until the box is opened and it is observed.
Twitch Boy
Defacing this tagline is a MAX foul
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Heisenberg gets pulled over by a cop.
The cop asks "Do you know how fast you were going?"
Heisenberg says "No, but I can tell you exactly where I am."
Heisenberg gets pulled over by a cop.
The cop asks "Do you know how fast you were going?"
Heisenberg says "No, but I can tell you exactly where I am."
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Which is exactly what I said.
Which is exactly what I said.
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Rule 219. One or more safety valves on every boiler shall be set at or below the maximum allowable working pressure. The remaining valves may be set within a range of 3% above the MAWP, but the range of the setting of all of the safety valves on a boiler shall not exceed 10 % of the highest pressure to which any valve is set.
So when I said 'well below', what I should have said is 'at or below'. I'm not sure where your 6% -21% range comes from. I'm pretty sure the NBIC states the same as above. But then again I'm only licensed in MIchigan, Ohio, Kentucky, West Virginia, Penn. and NY. but not Texas. That 6% sounds familiar though. I think it has to do with capacity though, not pressure. The capacity of the valve(s) have to be such that they won't allow the pressure to get more than 6% above the highest valve lift point and never more than 6% above MAWP.
This may be different for nukes, I don't have a Nuclear endorsement for my National Commission.
According to my copy of the Michigan Boiler Code Rules, Rule 408.4219 Safety valve pressure setting states:
Rule 219. One or more safety valves on every boiler shall be set at or below the maximum allowable working pressure. The remaining valves may be set within a range of 3% above the MAWP, but the range of the setting of all of the safety valves on a boiler shall not exceed 10 % of the highest pressure to which any valve is set.
So when I said 'well below', what I should have said is 'at or below'. I'm not sure where your 6% -21% range comes from. I'm pretty sure the NBIC states the same as above. But then again I'm only licensed in MIchigan, Ohio, Kentucky, West Virginia, Penn. and NY. but not Texas. That 6% sounds familiar though. I think it has to do with capacity though, not pressure. The capacity of the valve(s) have to be such that they won't allow the pressure to get more than 6% above the highest valve lift point and never more than 6% above MAWP.
This may be different for nukes, I don't have a Nuclear endorsement for my National Commission.
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Actually, he's right. The overpressure allowances are dependent on a slew of factors. Process contents, vessel type, and relief device type (rupture disk, mechanical pressure relief valve, RD/RV combo, etc.)
The set pressure may be 150 psig, but they are allowed to open at 10% above the set pressure.
Actually, he's right. The overpressure allowances are dependent on a slew of factors. Process contents, vessel type, and relief device type (rupture disk, mechanical pressure relief valve, RD/RV combo, etc.)
The set pressure may be 150 psig, but they are allowed to open at 10% above the set pressure.
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
If I remember correctly, the ASME boiler code allows 6% overpressure. I'm not sure about that because I've done very little relief systems analysis at all recently, and I've never done very much with boilers and steam valves.
The high end of the range, 21%, is the allowable overpressure for external pool fire contingencies for non-boiler process vessels (typically governed by NFPA 30, ASME section VIII division 1, and/or API standards 520 part 1 and 521).
When I talk about allowable overpressure, I mean that the relief valve capacity must be enough that the pressure never goes more than that amount over the MAWP. That's independent of the set pressure, which indeed must be at or below the MAWP.
(I know this stuff pretty well because it's what I do for a living. My company does engineering consulting work on pressure relief and effluent handling systems, and I do the software that does a lot of the analysis and computation.)
If I remember correctly, the ASME boiler code allows 6% overpressure. I'm not sure about that because I've done very little relief systems analysis at all recently, and I've never done very much with boilers and steam valves.
The high end of the range, 21%, is the allowable overpressure for external pool fire contingencies for non-boiler process vessels (typically governed by NFPA 30, ASME section VIII division 1, and/or API standards 520 part 1 and 521).
When I talk about allowable overpressure, I mean that the relief valve capacity must be enough that the pressure never goes more than that amount over the MAWP. That's independent of the set pressure, which indeed must be at or below the MAWP.
(I know this stuff pretty well because it's what I do for a living. My company does engineering consulting work on pressure relief and effluent handling systems, and I do the software that does a lot of the analysis and computation.)
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Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Are you saying that if a SRV has a set pressure of 150 psig, that it is ok if it doesn't lift until 165 psig?? Cause I don't think so.
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
I agree, to my knowledge that's not true.
I agree, to my knowledge that's not true.
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
I don't even know if I have a Sect VIII. I figured with Chem Eng degrees and living in Houston you must deal a lot with the refining industry.
I don't even know if I have a Sect VIII. I figured with Chem Eng degrees and living in Houston you must deal a lot with the refining industry.
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
http://www.wermac.org/valves/valves_pressure_relief.html
http://www.wermac.org/valves/valves_pressure_relief.html
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
What really gets me is the anti nuclear people saying 'this is why we shouldn't have nukes'. I'll take them a little more seriously when they start demanding Japan build a 30 foot seawall north the south to prevent tsunamis from wiping entire villages off the map.
What really gets me is the anti nuclear people saying 'this is why we shouldn't have nukes'. I'll take them a little more seriously when they start demanding Japan build a 30 foot seawall north the south to prevent tsunamis from wiping entire villages off the map.
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Frustrating, isn't it?
Also, let's keep in mind these reactors were essentially designed in the 60s, built in the 70s, and are nearing the end of their life. Really? We're going to use these reactors as the posterchild for nuclear reactors that we would design and build in 2011? I hate people.
Frustrating, isn't it?
Also, let's keep in mind these reactors were essentially designed in the 60s, built in the 70s, and are nearing the end of their life. Really? We're going to use these reactors as the posterchild for nuclear reactors that we would design and build in 2011? I hate people.
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
"The problems were identified in 1975".
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
That's interesting. I read that the same way you do.
That one appears to be the normal 10% accumulated pressure limit (for non-fire contingencies protected by a single device).
dxmnkd316
Lucia Apologist
Re: Japan hit by 8.9 Magnitude Quake, Tsunami Warnings In Effect
Yeah, I included the second passage since it was referenced in the first. I didn't want to make it seem like I was hiding some minute detail.
(I'm not.)
I put in a few PSVs on a project I was on a few months ago. I've specified plenty of them before, but my new company has a "Pressure Vessel Coordinator" who is required to sign off on all relief and pressure designs. He and I went through our company's standard Excel workbook (yes, workbook - probably about 20 tabs
) for designing various relief systems as part of my training. That 10% tolerance was one that caught my eye as well.
I know I'm going to be interfacing with him quite a bit in the coming months. We're putting in an enclosed HF blowdown tank. That's when everyone's pencil gets sharpened and there is no tolerance for error. Plus there's the whole issue of needing to use balanced bellows valves and different vessels venting to the same blowdown tank but are rated for different pressures. Fugly stuff.
Yeah, I included the second passage since it was referenced in the first. I didn't want to make it seem like I was hiding some minute detail.
(I'm not.)I put in a few PSVs on a project I was on a few months ago. I've specified plenty of them before, but my new company has a "Pressure Vessel Coordinator" who is required to sign off on all relief and pressure designs. He and I went through our company's standard Excel workbook (yes, workbook - probably about 20 tabs
) for designing various relief systems as part of my training. That 10% tolerance was one that caught my eye as well.I know I'm going to be interfacing with him quite a bit in the coming months. We're putting in an enclosed HF blowdown tank. That's when everyone's pencil gets sharpened and there is no tolerance for error. Plus there's the whole issue of needing to use balanced bellows valves and different vessels venting to the same blowdown tank but are rated for different pressures. Fugly stuff.
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