Prestige Pressure Cooker problem

[Lucky Luke]

Hello: I hope that it isn't out of order to post about a pressure cooker! The thing is, many readers use these contraptions, so someone may be able to help me with a problem that has stumped me.

Our Prestige (stainless steel) pressure cooker is many years old. I don't know what model number it is, either. Anyway, last week, my wife complained that it was not getting any pressure (only she does the cooking, not me). She had already replaced the gasket with an unused (bought new) one that had been in the drawer for years, and now, she thought, was the time to change it. However, it still would not get pressure up. Since, on the lid, there is only 3 things (an indicator that shows that pressure has been gained; the little funnel, on which the weight is placed, and a "Ready=to-Serve Indicator"), it could only be one of these three things that was at fault. The weight cannot be it, because after all, it is only a weight. There seems not to be the slightest reason to suspect the pressure indicator (which is a kind of metal stud — about three eights of an inch in diameter — in a plastic surround in the middle of the lld). That would make suspicion fall on the "Ready-to-Serve Indicator", which is a rubber plug, about five eighths of an inch in diameter, set into the lid near to the edge, and which has a metal peg in it. Shortly after the weight has been put on the pressure cooker (with gas-ring full on). this metal peg is supposed to pop up, and seal the only vent through which steam can escape. This then allows the cooker to build up pressure and cook the food.

When I prised out the rubber plug of the "Ready-to-Serve Indicator", the rubber started to break up, being brittle. Ah, I thought, this is the culprit! Yet, after a new one has been fitted (bought fresh from a store on the Web), the pressure still does not increase, and it is therefore impossible to cook in this pressure cooker. The metal peg in the R-to-S Indicator does not pop up automatically, as it should, but even when I pull it up manually (to help it, as it were), the cooker still does not gain pressure.

I am completely at a loss as to how to get this appliance to gain pressure! Can anyone make any useful comment?
With thanks in hopeful anticipation,
L.L.

 

[Stivino]

When it starts to boil steam will be produced. If it isn't holding pressure, the steam will leak. Wherever it leaks from will show you the faulty part.

 

[Alec_t]

If pressure doesn't increase then steam must be escaping. Can't you see where?

 

[Lucky Luke]

If pressure doesn't increase then steam must be escaping. Can't you see where?

Some steam leaks from the gasket, that is clear. However, it is a previouslyi unused gasket, and anyway, my wife says that this did happen (for a time), even when the cooker worked. What steam is being lost doesn't seem enough to make it not build up pressure, though.
L.L.

 

[Old Salt]

Are all the faces scrupulously clean. I would remove the gasket and the 2 seals and give everything a good clean, reassemble and try again. Years since we had a pressure cooker but I thought one of the smaller seals with metal peg as a safety valve and only rose up when overpressurised.

 

[elisa123]

The company used to have a very helpful technical department. Phone them or send an email.

 

[Lucky Luke]

Are all the faces scrupulously clean. I would remove the gasket and the 2 seals and give everything a good clean, reassemble and try again. Years since we had a pressure cooker but I thought one of the smaller seals with metal peg as a safety valve and only rose up when overpressurised.

Yes, Old Salt, the pressure cooker is very clean. With regard to the peg popping up, my wife (who is the only user of the p. cooker) says that, if it got overheated, the bottom of the peg would melt. She seems to be certain about this, and says that the peg needed to be pushed up through a kind of "flap" in the rubber disc (a point of slight resistance), to work aright. Again, she is confident about this, and I had been trying to get pressure up with it not having pushed through the "flap". Another thing she says is that, when i was giving it a try-out, there was only water in the bottom of the pan, and no food in the cooker (I was only interested in testing the pressure). Therefore, my wife said that it was too big a volume of space to get pressure up easily. She is now confident that, tonight when she uses it to actually prepare food, it will work.
If she proves to have been mistaken, I shall report here, with egg on my face.

Thanks to all that have replied!
L.L

 

[Lucky Luke]

The company used to have a very helpful technical department. Phone them or send an email.

Elisa, I bet that was a long time ago! Prestige closed down years ago.
L.L.

 

[Harry Bloomfield]

She seems to be certain about this, and says that the peg needed to be pushed up through a kind of "flap" in the rubber disc (a point of slight resistance), to work aright. Again, she is confident about this, and I had been trying to get pressure up with it not having pushed through the "flap".

I'm with Old Salt, on this - the pin is a safety valve. The weight on top, used to be adjustable, the more weight the higher the pressure. The weight being lifted, and steam blowing out, was the indicator that it was up to pressure, start time for the cook.

At the end of the cook period, the heat source was turned off, the weight taken off, which released all the pressure, after which the lid could be opened.

 

[Lucky Luke]

I'm with Old Salt, on this - the pin is a safety valve. The weight on top, used to be adjustable, the more weight the higher the pressure. The weight being lifted, and steam blowing out, was the indicator that it was up to pressure, start time for the cook.

At the end of the cook period, the heat source was turned off, the weight taken off, which released all the pressure, after which the lid could be opened.

Harry, I have no intention of contradicting you, as I can only quote what my wife tells me about the rubber disc with the peg in it (the "Ready-to-Serve Indicator'. What a strange name to give to this part! It does not indicate that food is ready to serve, at all! However, that is its official name. Anyway, my wife swears that this pops up after a short time (when she uses the p. cooker, anyway). She must have waited, scores of times, for it to pop up. After this, she puts the weight on and twists it. And she has used this p. cooker successfully, for many years. She is aware that the pin is a safety-valve (but insists that it would melt, if the cooker becomes overheated). But again, why the heck is it called a Ready-to-Serve Indicator? They can be seen on Amazon and eBay by that name.
I can't wait to find out what happens, when she prepares the evening meal tonight.
L.L.
PS: It just occurred to me that it may be a model that you are not familiar with. It's donkeys' years old.

 

[Harry Bloomfield]

PS: It just occurred to me that it may be a model that you are not familiar with. It's donkeys' years old.

Maybe you are correct then - my only experience of them, was as a lad, my mother using one. I was fascinated by it, , and remember the weights were concentric, with a loop at the top. You screwed the weights on or off, to adjust the pressure achieved. I remember her timing the cooking, from when the steam began blowing out, but don't remember anything about the pin, other being told it was a safety valve, in case the weighted valve became blocked.

 

[Alec_t]

the rubber disc with the peg in it (the "Ready-to-Serve Indicator'. What a strange name to give to this part! It does not indicate that food is ready to serve, at all!

It's not so strange. If seems that valve is designed to close at the start of cooking and stay closed during cooking. At the end of cooking the hob is turned off and pressure is allowed to drop. For safety's sake (risk of scalding water spraying out) the cooker must not (indeed cannot) be opened until the pressure is almost at atmospheric, at which point the valve will open and the cooker can be opened. So the valve opening is an indicator.
Failure of that valve to close/seal at the start of cooking would explain lack of pressure build-up, as you reported.

 

[Lucky Luke]

It's not so strange. If seems that valve is designed to close at the start of cooking and stay closed during cooking. At the end of cooking the hob is turned off and pressure is allowed to drop. For safety's sake (risk of scalding water spraying out) the cooker must not (indeed cannot) be opened until the pressure is almost at atmospheric, at which point the valve will open and the cooker can be opened. So the valve opening is an indicator.
Failure of that valve to close/seal at the start of cooking would explain lack of pressure build-up, as you reported.

Thanks for that lucid explanation of the term in question, Alec_t. It really has puzzled me, and your explanation makes perfect sense. Also, it bears out what I said about the metal pin popping up before the weight is put onto the lid. Yesterday, my wife gave the new Ready-to-Serve Indicator a test, by putting food into the p. cooker. Now that it was not (as in my trial run of yesterday) only space inside the p. cooker, the metal pin popped up, just as she said it would. After she put the weight on, the food cooked perfectly, because this time, there were no leaks of steam. So, the problem that I first asked about has been solved; also, I have learned something new. Thanks very much, to all that took the trouble to reply or comment!
L.L.

 

[Harry Bloomfield]

It's not so strange. If seems that valve is designed to close at the start of cooking and stay closed during cooking. At the end of cooking the hob is turned off and pressure is allowed to drop. For safety's sake (risk of scalding water spraying out) the cooker must not (indeed cannot) be opened until the pressure is almost at atmospheric, at which point the valve will open and the cooker can be opened. So the valve opening is an indicator.
Failure of that valve to close/seal at the start of cooking would explain lack of pressure build-up, as you reported.

Right, I think I see now - the pin gets sucked in by the vacuum, as the cooker cools down. I had in mind it popping out, from the pressure.

 

[lloyda]

Right, I think I see now - the pin gets sucked in by the vacuum, as the cooker cools down. I had in mind it popping out, from the pressure.

No. The pin drops down under gravity when internal and external pressures are the same. It is forced up as the cooker warms up by the flow of steam through the hole, and then the increase in internal pressure ensures a good seal.