You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
pressure loss
A loss-of-pressure-control accident (LOPA) is a mode of failure for a nuclear reactor that involves the pressure of the confined coolant falling below specification. Most commercial types of nuclear reactor use a pressure vessel to maintain pressure in the reactor plant. This is necessary in a pressurized water reactor to prevent boiling in the core, which could lead to a nuclear meltdown. This is also necessary in other types of reactor plants to prevent moderators from having uncontrolled properties.
Pressure is controlled in a pressurized water reactor to ensure that the core itself does not reach its boiling point in which the water will turn into steam and rapidly decrease the heat being transferred from the fuel to the moderator. By a combination of heaters and spray valves, pressure is controlled in the pressurizer vessel which is connected to the reactor plant. Because the pressurizer vessel and the reactor plant are connected, the pressure of the steam space pressurizes the entire reactor plant to ensure the pressure is above that which would allow boiling in the reactor core. The pressurizer vessel itself may be maintained much hotter than the rest of the reactor plant to ensure pressure control, because in the liquid throughout the reactor plant, pressure applied at any point has an effect on the entire system, whereas the heat transfer is limited by ambient and other losses.
Any ideas about this anyone ?
I am filling the boiler to 1.5 bar every 24 hours, pressure gauge is at absolute zero.
No obvious sign of any leaks anywhere and this has been going on for a couple of weeks now and would anticipate a visual on a leak now.
Boiler installed 14 months ago.
Plumber...
help needed .... i have a pressure loss on 8 year old floor mounted combi.. No sign of water leaks through boiler(prv) or central heating system....... Could it be a split main heat exchange if so how do i check?
oliver reeves
Thread
boiler
constant
floor
pressurepressureloss
system
which
Hi all - in need of advice
I am experiencing a pressure loss on my Alpha boiler on a daily basis. There is a constant dripping coming out of a copper pipe on the outside of my house - I think this is the pipework from the pressure relief pipework. The boiler works ok but because of this leak...
I have had my vaillant for 5 years. It was serviced after first year and again this year .
For the past month i have had to top pressure up at least once a week. This last week i have done it daily.
After i had it serviced last week, the engineer said i must have a leak beneath ground level...
bigbird
Thread
ecotec
ecotec plus
ecotec plus 837
plus
pressurepressureloss
vaillant
Hi
Please help. I am filling my heating up every 30-40 minutes, but even when its not running its leaking out of the condensate pipe outside.
Any advise would be great.
Rob:mad2:
RoBBster
Thread
combi
engineer
ideal
ideal logic
logic
looking
please
plumber
pressurepressureloss
water
water pressure
Hi - I'm looking for some advice on a constant boiler pressure drop. Its a pressurised system in the garage with a Main 28kw boiler 2 years old. Ive had the problem about three weeks or so now. Ive checked the pressure for 4 days at the same time when the system is cold and the pressure dropped...
laguna
Thread
boiler
oil
pressurepressureloss
running
system
water
Hi
I'm new and as the name says 'indespair'
I rent a new build flat; it has a 1 year old Vokera Compact 29 boiler.
It started losing pressure at the end of Oct.
The heat exchanger has been replaced; the boiler fully checked [twice] for leaks.
The pipe work has been checked twice for leaks...
New to the forum and not a plumber/heating engineer so be kind :D
I've been having a problem with pressure loss in my Worcester 24CDi BF. I have trawled the internet and tried various trouble shooting pointers but am now struggling, here's the scenario.
The problem is a long term one, as a...
Vossy1
Thread
color
expansion
pressurepressureloss
system
vessel
water
worcester
Hi I know this subject has been covered a few times over. But i would appreciate your thoughts. I have been alled to a fairly big house which runs underfloor heating and a 300l unvented cylinder. It's basically a primary loop which does the cylinder and the the manifolds one upstairs and 2...
Hi,
I have recently been having pressure loss of about 0.2 - 0.3 bar per day. I will top the system up to 1.5 bar in the morning and by the evening it has dropped to 1.3. If I leave it longer e.g. a couple of days it drop even more 0.7 etc etc I have not let it get lower than 0.7 before I top...
On a boiler over 30kw that has a 15mm gas connection, how can you calculate pressure loss of the final 15mm pipework.
usually the final 1m is reduced to 15mm, however 15mm pipework is only rated at 2.9m3/hr over 3m, with no data for shorter runs in most of the tables.
A 30kw boiler will have a...
cascas
Thread
15mm
boiler
connection
elbow
gas
oil
pipework
pressurepressureloss
Hi all,
I have been persistantly adding water to my sealed system over the past week, because everytime i top up the water to ~1bar over the following days the pressure slowely decreases. have i got a leak? can i dod anything to test my system? is it to do with the expansion bottle? i have bled...
sniperkmydj
Thread
constant
expansion
glow
glow worm
glow-worm
pressurepressureloss
should
system
vessel
water
worm
PRESSURE LOSS (water) - Ravenheat CSI85 condensing boiler - Hepworth plastic piping. 7 small radiators - 5 large radiators. 6 years old.
Any suggestions ?
Needs repressurizing about each 48 hours.
Loss started after boiler CH temperature was increased - by using control knob on boiler - by...
I have a Worcester-Bosch greenstar boiler which is approximately 4 years old, I know absolutely nothing about plumbing apart from there are plenty of cowboys out there.
My boiler pressure is all over the place, it feeds 8 fairly big radiators on a closed system. Recently there's been a slight...
I have a Glow-Worm 30sxi running a mixed underfloor and radiator heating system and Megaflow hot water system. The boiler is about 4 years old and was serviced a couple of months ago. There was a small amount of air in one radiator when I turned the heating on this autumn so I bled the radiator...
Customer's sealed heating system is losing pressure from about 1 bar to zero overnight. Pressure rises to 2 bar when heating is on.
No water was discharged from the PRV and no other major leaks.
Expansion vessel is still at 1 bar (same as 2 weeks ago).
The pressure rises very quickly when...
Hi forum,
I had a new Ideal logic installed last year, in the past few months approximately every month the boiler losses pressure completely....this happens literally in one hit.....once re filled to 1 bar bolier works fine then suddenly a few weeks down the road complete pressure...
Hi
I have a Worcester Greenstar 40CDI Conventional boiler. The boiler and CH system is just under 2 years old and never caused an issue but has suddenly become prone to pressure loss .
A recent radiator removal and draining of system was taken 2 weeks ago with no problems up until 2 days ago.
We...
approach
Thread
boiler
calibri
color
conventional
greenstar
oil
pressurepressureloss
water
worcester
Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.