Actually having now read Robin's post, the use of the term does makes sense. i.e. when the pressure is vented back to almost atmospheric, the safety valve will fall, acting as an indication its safe to open the cooker.
Because he knows nothing about pressure cookers? Personally saw the result of my grandmothers cooker safety valve blowout.
NOT a safety valve shit-fer-brains. See post above.
Brain dead as usual. The safety valve only opens on OVER pressure. It closes when pressure is NORMAL or lower.
FTAOD I never doubted that *you* knew what the various gubbins did and how to interpret them :)
Ignore Harry who is just blowing off steam (or some other vapour).
The Prestige design in question was very different from other pressure cookers but rather clever [if it worked!] as it had 3 failure modes. (And I'm sad enough to have checked the manual)
a. if the pressure rises above safe levels the metal "pintel" is meant to pop up to vent the cooker b. failing that, the whole Ready to Serve plug is meant to blow out c. failing that, the metal pintel melts
That is what Prestige called it.
In this context, it indicated that it was safe to open the lid when the small metal 'pin' dropped.
The instructions also mentioned watching it during the pressurisation stage, if I recall correctly as an indicator when to reduce the heat.
As for fitting it incorrectly. The on on ours was in a cone like grommet which probably could fit the wrong way. If so, the 'bar' which retained the centre pin would be useless and the shaped head could easily be forced out under pressure. I was always dubious of the grommet shape, if they have inverted the cone (so it is forced into place if fitted correctly) I wouldn't be surprised. If so, fitting it the 'old way' could result in the incident described.
"Safe to open" would seem a more sensible name than "ready to serve".
Tim
Even more accurate would be "in a state where it will not spew superheated water and grease over the entire kitchen while simultaneously throwing a heavy metal lid into the cook's forehead when opened". I'd guess that my version would not be the one that ends up in the instructions.
Also, that "ready to serve" replaced "safe to open" because the latter suggests that a pressure cooker could somehow be unsafe...
Thomas Prufer
it's not a safety valve that's why. When the cooker has sufficiently cooled, the pin is sucked in, indicating that pressure has equalised and the lid can be removed.
The vessel can't be opened under pressure, there are indents on the locking ring prevent this. Any pressure vessel can be dangerous, especially when filled with a compressible gas/vapour
They are to indicate when the pressure has dropped so its safe to open the lid. If you open it while the indicator is up you can expect a visit to A&E or worse.
Oh I know what it does, just never heard it called a "ready to serve" indicator.
Really?
Yes
You must me
Earlier you said that it was a vent to let air out - and that it does that before pressure is achieved... it could only do this if open, so make your mind up!
Let me explain it to you since you obviously have no idea.
In the non pressured state the floating metal part of the valve is "loose" and hanging in the rubber grommet. Thus is its "open". As the rate of steam generation starts to build, it will initially escape through the open safety valve past the floating metal bit, until the rate of escape blows the floating metal centre hard enough to push it against the grommet. From that point on it is now closed and sealed.
During a normal cooking cycle it will stay that way until the pressure reduces back to ambient (by virtue of being vented from the dead weight valve - either by virtue of it being lifted off as on some designs, or like on mine, where it is rotated to the ** or 2 position where it vents. Once back to a non pressurised state, the metal part of the safety valve will fall back to the open state (this is the so called "ready to serve" part of its function).
If during cooking something goes wrong, like the dead weight valve is defeated and the pressure rises too far, then the safety valve will let go, allowing the metal centre (and possibly the whole grommet) to be ejected, thus venting the cooker.
True of some like the prestige, but not one ones like the Tefal design with has a large metal bar across the top of the lid, the ends of which engage in lugs on the side of the pan, and its then jacked up using a knob on top.
I think that harry has taken on the mantle of dribble. He seems to see it as his duty to argue night is day just so that he can disagree with every post!
Page 10.
Since you seem unable to find it I'll copy out a bit:
"3. Ready to Serve Indicator acts as a safety valve giving 3 separate levels of protection.
If there is a build up of excess pressure in the cooker, the metal pintle will pop up allowing vertical release of steam through the centre hole. This will reduce the pressure.
If the excess pressure is not reduced then the whole of the rubber safety plug will blow out. This will allow a vertical release of steam to reduce pressure.
If the cooker boils dry or becomes too hot, the metal pintle in the centre of the Indicator will melt allowing the excess pressure to be released."
In short, just like we have been telling you.
I trust you will now move on to that apology.
More usefully for brain dead Harry...
Be aware of UP and DOWN ByMr. Derek Lawon 7 October 2009 Verified Purchase
Especially if you are replacing a very old safety valve, it is not obvious which way up these go. The old ones are flush to the top of the cooker, and these are flush on the inside. Very close examination does reveal an embossed "top" on the rubber, and I advise you to seek it out. A diagram on the packet would have saved the kitchen ceiling from a goodly quantity of chicken stock, and the rest of the kitchen furnishings from chicken rain!
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