fix safety valve pressure cooker free sample

Pressure cookers have become commonplace in modern households, and their improved safety features have made them twice as popular. In the past, pressure cookers earned a dark reputation for explosions, but today, most pressure cookers have a minimum of 10 or more safety features.

That said, when the pressure cooker safety pressure valve starts leaking, you should know the cause because pressure cookers must release steam to stay safe.

You find many pressure cooker safety valves on top of the lid near the handle, but this depends on the type. If you see a leak from here while pressure cooking, that doesn’t always mean danger.

The safety valve releases the steam to lower the pressure to safer levels and regulate the pressure. The newer models, like the electric pressure cooker, even release the steam using a computer chip. A pressure cooker model like this will release light vapors or condensation from the safety valve, which doesn’t pose a danger.

Important to note: The safety valve leaking doesn’t pose a danger as long as the pressure cooker continues to build to the desired PSI. Once you reach your desired PSI, the safety valve should stop leaking altogether. If it continues to leak, that indicates pressure control failure.

Pressure cookers will open the safety valves enough to release the pressure cooker steam building in the pot. This causes a hissing sound or rattling sound. Don’t feel intimidated that is normal. If you wanted a quieter pressure cooker, electric pressure cookers don’t make as much noise.

You must maintain consistent pressure to ensure that the pressure cooker will cook the food all the way through. Safety valves can be bought and replaced if you have a broken one. However, buy a quality safety valve from any of the reputable brands to ensure the quality.

Manufacturers made safety valves to protect consumers from exploding pressure cookers. If you have a defective safety valve that doesn’t leak, you could use it. You could use it, but you wouldn’t be wise to do it. Don’t do this.

Safety valves let out the dangerous excessive steam. When they leak, they let out steam unnecessarily, and the pressure cooker won’t cook the food. On the other hand, when defective and closed, you have a higher risk of it exploding. Never use a pressure cooker that has either a leaking valve or a defective valve.

You don’t want to see steam exiting the safety valve because the leaking from high pressure can put you in a dangerous situation. The escaping steam can cause second and third-degree burns if exposed to the skin. If you notice a leak, immediately turn off your pressure cooker from the heat source and release the steam. Even smaller leaks pose a danger.

Steam exits from the safety valve of your pressure cooker because of a broken disc, or rubber gasket, on the inside. Because of this, it releases too much steam and the vessel never boils. If you have damage to the valve, you will see a hole in the valve.

Warning: Working on the safety valve yourself does pose a small level of danger. Do this at your own risk. If you don’t want the risk, then take it to an authorized service center. A utensil repair professional can also repair this, but it depends on how much damage was done to the pressure cooker.

Buying a low-quality pressure cooker could be the cause of why these products don’t last long. They have a proneness to issues. You should also clean and maintain your pressure cooker after each use because it can begin to leak if not cleaned properly.

As we said, you can use two methods to replace the safety valve if you have a leak: You can replace it from the inside of the lid, or you can replace it from the outside of the lid. Before attempting either consult your user manual.

To replace the safety valve from the outside, you will use a screwdriver on the outside to turn the screw, while you hold the screw and keep it from twisting on the inside. Once it releases, use a cotton swab to clean the inside of the hole.

Check for surface damage as well to make sure that you don’t have structural problems. Examine the o-ring as well to make sure that it doesn’t have defects. Replace the safety valve with the new one and tighten it up.

From the inside, you will use a wrench to unscrew the safety, while the screwdriver will hold the screw in place. Once you have released it, do the same thing as you did with the first method. Replace the safety valve and tighten it back up.

While you can replace them via the DIY method, don’t try to fix a broken safety valve. The replacement parts only cost between $2 to $17 to replace a safety valve. Buy from a genuine brand because it guarantees that you fix the problem.

Considering the cheap cost, you may want to buy a spare because you can replace it at a moment’s notice. When the pressure reaches a dangerous level, the safety valve acts as the canary in the coal mine. This blows out before it explodes. The safety valve attempts to bring the pressure back down to a normal level.

Never use a damaged valve because it doesn’t provide the same level of protection. You may experience similar problems as before like the valve leaking, or the valve shutting down altogether. Both scenarios put you in a dangerous situation.

The safety valve leaking poses a danger at the first sign of damage. With that in mind, a leak only gives you one example of what can happen to them. You should replace the safety valve whenever it becomes cracked or brittle. As soon as you see the damage, replace it.

Inspect the safety valve for signs of wear before each use. Another reason that manufacturers say to only fill the pressure cooker two-thirds full is that it ensures that the food doesn’t block the safety valve. The pressure cooker will build a dangerous level of pressure if that happens.

Let’s say that the food blocked the pressure release valve. The safety valve may melt to release the steam. That becomes the last stop before the pressure cooker explodes. The valve helps to maintain the pressure levels. While you have other safety features, this component especially protects you.

Thorough cleaning after using your pressure cooker will go a long way to helping it stay in tip-top condition. Handwash the pressure cooker lid with soap and warm water. Never put a pressure cooker in the dishwasher because this can be hard on the more sensitive components like the gaskets and rubber ring or seal.

A leaking safety valve doesn’t always mean danger, but look for the cause if it continues after you reach the desired PSI. Some steam leaking is normal, but you shouldn’t see an excessive amount of it leaking. That indicates that your pressure cooker has too much pressure.

Never try to repair a damaged safety valve. You can simply replace them, but if you don’t feel comfortable doing it yourself, hire a professional. Always pay attention to leaks because they can stop your pressure cooker from building pressure.

Such a valve assembly is known from German laying-open print DOS No. 2,606,676. The pressure relief means thereof consists of a check valve which also serves as a safety valve. It has a valve housing of a resilient material which is fitted into a hole in the cover in the vicinity of the cooking valve aperture. The closure body is designed as a shaft-shaped valve body, transverses the valve opening and supports two spaced valve disks inside the cover as well as a dome-shaped head outside the cover. The head abuts against the valve opening in the pressureless state. As the pressure builds up in the pressure-cooker, however, the valve body is lifted and the upper valve disk closes off the valve opening internally so that the pressure in the cooker can build up. When the pressure becomes excessive, the upper valve disk can move outwardly through the valve opening of the valve housing. This allows steam to escape through the valve opening. The second valve disk preventing the valve body from being blown off the cooker although it does not obstruct the escape of steam. The cooking valve usually comprises a spring-loaded valve and a displaceable pressure indicator for the cooker which is located therein and is also spring-loaded. The springs press against the interior of a cap which is adapted to be screwed on to the valve housing. In the known valve assembly, the cap of the cooking valve has an asymmetrical design on the underside facing towards the cooker cover. It features a guide bevel at this location which reduces its clearance height. In the normal cooking position, the area with the maximum inner clearance height overlaps or overlies the check valve. When the cap is screwed off, the area with a minimum clearance height comes to lie above the check valve over which it can move without obstruction when the head of the check valve abuts against the outer side of the valve seat in the completely pressureless state. If the check valve has closed due to the internal build-up of pressure in the cooker, ie if the upper valve disk abuts against the valve seat, the guide bevel presses the valve body of the check valve downwardly and steam can escape through the check valve. The pressure in the cooker is relieved, whilst the person using the cooker is warned simultaneously by the sound of the escaping steam not to unscrew the cap any farther. If the valve body has been raised only slightly owing to a slight superpressure in the cooker, eg at the onset of pressure build-up, an additional stop which projects into the clearance height prevents the cap from being rotated any farther.

The known valve assembly is expensive to manufacture, since it requires a valve housing and a valve body for the pressure relief means. These parts are expensive to manufacture and to assemble. The cap of the cooking valve is also expensive to produce owing to its asymmetrical shape, and the dimensions of the guide bevel as well as the region of reduced clearance height must be kept within a narrow tolerance range: the valve body must be pressed downwardly to open the valve on the one hand, although on the othe hand this must not be so far that the valve head closes the opening externally. Another drawback is that when the cap is rotated into the open position, the stop jams the head of the valve body and this cannot return to its original position, even when the cooker is not under pressure, until the cap has been turned back somewhat. When the check valve functions as a safety valve, the valve disk cannot automatically turn back any longer due to the valve opening. The cap cannot be screwed off over the projecting valve body either. This makes it impossible to gain access to the valve body and return it to the normal position. Yet another disadvantage is that the valve body of the check valve can only be cleaned thoroughly--quite essential for proper sealing--if it has been snapped out of the valve disk. Since this is complicated and troublesome, such cleaning is frequently postponed or forgotten completely.

A valve assembly comprising a pressure relief means disposed adjacent to the cooking valve is also known from German utility model No. 7,624,730. The pressure relief means is designed as a safety valve in the form of a check valve. The cap of the cooking valve has indents on the periphery thereof. Both valves are spatially associated with one another such that the valve body can be raised adjacent to such an indent only when the cap is in certain positions. The check valve can be closed and pressure built up in the cooker only in this position. When the valve body is in the raised position, ie when pressure has built up in the cooker, the valve body in turn locks the cap of the cooking valve which cannot be rotated. Hence, the vent opening cannot be opened by adjusting the cap. This known valve assembly, which therefore does not correspond to the preamble of the present invention, is expensive to manufacture due to the design of the check valve. It is also difficult to clean, since the steam is dissipated to one side through a cavity in the cooking valve beneath the cap when the safety valve responds to excessive pressure. These cavities are difficult to reach, even after the cap has been removed. Furthermore, the valve body cannot be turned back into its original position until after the safety valve has responded and the excess pressure has been vented off. Only then can the cap be removed from the cooking valve.

The object of the present invention is to provide a valve assembly according to the preamble of the claim which is economical to manufacture, easy to clean and simple to operate in all modes of operation.

The construction of the closure body as a seal disposed on the cap makes it possible to design the vent opening in the form of a simple hole in the cover without any valve housing. Such a hole can be produced during one and the same operation as the hole for the cooking valve. It is easy to clean. The arrangement of the associated seal in the cap gives rise to a constructional design which is simple and easy to clean. This construction of the pressure relief means is made possible by the recognition that the vent opening need only be open to relieve the pressure. An open valve is unnecessary prior to a pressure build-up, since the air being heated up can escape by way of the conventional sealing rings between the pressure-cooker and the cover until the sealing ring abuts sealingly against the cover and cooker wall due to the build-up of pressure. In the pressure relief means in accordance with the invention, the co-operation of the seal and the vent opening permits steam to escape even when the cap is moved minimally towards the venting position. The pressure in the cooker decreases immediately. Moreover, the co-action of the venting opening and the seal generates a warning sound which warns the cook not to opening the cooking valve while the cooker is still under pressure. If there is no seal in the cap, no pressure will build up in the cooker at all.

The seal can advantageously consist of a material which is so resilient that it sealingly closes the vent opening at normal cooking pressure and permits pressure to be vented should it become eccessive. The pressure relief means thus functions as a safety valve as well.

The annular seal advantageously has an internal diameter which is smaller than the external diameter of the cap section it surrounds. The annular seal is thus seated in the cap region in such a way that it can be neither twisted nor lost. Dirt cannot readily collect between the cap and the annular seal so that the seal does not have to be removed every time the cooker is cleaned.

FIG. 1 indicates the cover 1 of a pressure-cooker. A valve housing 2 is firmly riveted into place in the cover 1. It includes a valve seat 2a against which a valve body 3 is urged by a valve spring 4. This valve spring 4 presses against the inner side of a cap 5 overlying the entire valve assembly and designed as a cap or acorn nut. A pressure indicator 6 is displaceably mounted in the valve body 3. It is pre-biased by a pressure indicator spring 7 which presses against the valve body on the one hand and, on the other hand, against the inside of the cap 5. The cap 5 is adapted to be screwed on to the valve housing by means of a thread 8, thereby determining the tension of the valve and pressure indicator springs.

The cover 1 has a hole 10 in spaced relation from the valve axis and is located between the internal and external diameters of the annular seal. It serves as a vent opening and is closed by the annular seal 9 during cooking.

The afore-described valve assembly functions as follows during cooking: the cap 5 is screwed down to the stop with the inscription "cooking" adjacent to the arrow 12. The valve spring as well as the pressure indicator spring are both pre-biased in this position. The annular seal 9 closes the hole 10. Steam pressure can now build up in the cooker in the known manner once the warm air has escaped between the cooker and the cover as mentioned above. The cooking pressure is chosen by regulating the supply of heat in response to the position of the pressure indicator 6. At the conclusion of cooking, the cap 5 is turned half a turn to the "venting" position. This causes the annular seal to release the hole 10, the steam can escape and the pressure is relieved. The venting is continuous and dependent on the speed of rotation.

If the pressure indicator is not observed during cooking, i.e. if the supply of heat is not turned down at the proper time, thus causing the pressure in the cooker to become excessive, the steam can escape through the hole 10. This gives off a warning whistle and deforms the annular seal 9. Should the generated steam still be excessively high, the valve body 3 is lifted off its seat 2a.

I don’t deny that raising pressure too quickly results in undercooked food. I am just questioning, and trying to understand why it is so. I don’t think you fully understand the reason behind it either.

Again, no. the overall pressure is determined by the pressure regulating mechanism. Not by what is inside. That is a (nominal) 15 psi. Regardless of whether it is air, steam, a combination or something else. Once the gauge indicates 15psi, then the overall pressure is 15psi. Not something lower. Temperature is another question. At the start of this, I would have said it remains the same as for a given volume, pressure is proportional to temperature (Avogadro’s Law), but I haven’t seen anything that clearly backs me (or you) up, so now I am not so sure. Hopefully when I get a chance to read further I will get it clarified. Ideally I will find experimental evidence. It’s a shame I no longer know people who would be able to set up an experiment for me.

Observed fact: Food cooked in a pressure cooker brought to pressure at full power on an induction stove is under done if cooked for the recommended time

5. the pot does not heat up properly in the shortened time to pressure so heat that would otherwise go into the food is diverted into heating the container.

F. J. HOLBIK March 25, 1952 SAFETY AND RELEASE VALVE FOR PRESSURE COOKERS Filed Jan. 30, 1948 Patented Mar. 25, 1952 SAFETY AND RELEASE/VALVE FOR PRESSURE COOKERS Frank J. Holbik, Racine, Wis., assignor to Speed- Meal Corporation,Racine, Wis., a corporation of Delaware Application January 30, 1948, Serial No. 5,472

This invention relates to a combined safety and manual release valve for pressure cookers and has for its principal object the provision of a new and improved valve of this kind.

It is a main object of this invention to provide a safety-release valve for pressure cookers that is securely fixed on the cooker and yet is free to move with respect thereto, as required in the operation of the valve.

Another object of the invention is to provide a combined safety and manually-operated release valve that is really safe even in the hands of an inexperienced operator.

Another object of the invention is to provide a manually-operated valve incorporated in a pressure-operated safety valve and in which the operation of the safety valve is automatically checked at the end of each manual operation.

Another object of the invention is to provide a safety valve which is of pleasing appearance and which can be manufactured at low cost without sacrificing quality.

Further objects of the invention not specifically mentioned here "will be apparent from the detailed description and claims which follow, reference being had to the accompanying drawings in which a preferred embodiment of the invention is shown by way of example and in which Fig. 1 is an elevational view partly in section showing the improved valve;

consist of a vessel having a handle and closed by a cover likewise having a handle, are sealed by suitable gasket means carried by the cover and engaging the vessel. To guard against the building up of an excessive pressure in a cooker oi this type, a safety valve is usually provided and located at the center of the cover.

. In. certain prior art cookers of which I am i ware, after the cooking operation has been completed, it is necessary to remove the cooker and contents from the stove and hold the same under a cold water faucet to reduce the pressure therein so that the cover may be removed. In other instances there is incorporated in the safety valve a manual valve which may be opened to permit gradual escape of the pressure so as to reduce the pressure in the cooker down to practically zero so that the cover may be safely removed. It is to the improvement of a combination safety-release valve of this type that the present invention particularly relates.

- When the cover is removed from a pressure cooker at the end of a cooking operation, steam will condense on it and it is natural for the housewife to turn the cover upside down so as to hold this condensate in the cover. In certain prior art pressure cookers, the safety valve i not secured to the cover and consequently when the cover is overturned the valve falls off and is quickly damaged or lost. Ihe present invention further provides for securely attaching the safety valve to the cover so that itwill not fall off when the cover is turned upside down.

Housewives, housekeeper and the like, are hot skilled mechanics, and while many of the prior art safety valves are perfectly safe when properly operated, these operators have succeeded in manipulating these valves so inefiectively as to cause them to jam or otherwise fail to operate as intended. The present invention seeks to remedy this fault by providing a combination safety and manually operated valve in which the operation of the safety valve is automatically checked at the end of each manual operation.

In the operation of a cooker equipped with a valve of this type, at the end of a cooking operation the manual valve is operated to permit escape of the pressure slowly at first, and the valve further operated to permit complete release of pressure so that the cover may be removed with absolute safety. In the ordinary operation of the device, the valve is left in this open position and when the cooker is next used, as the water in it starts to boil air is blown out of the valve, and when all of the air is thus expelled and steam starts emerging from the valve the manual valve is closed to seal the-cooker pressure-tight.

In closing the manual valve, the Weighted cap is elevated and supported by the valve element which it contain and it is not necessary that this valve element be screwed clown tight onto the cap; however, most operators will screw it down farther than necessary. This act has resulted in the jamming of certain valves of the prior art of which I am aware; and in the present valve, if the operator screws the valve down too far, the housing and valve are automatically elevated to open the valve and permit excess steam to escape. If the valve should be jammed by this operation, it will be jammed in open position and buildingup of dangerous pressure in the cooker is thus definitely avoided. Ordinarily, as soon as the housewife hears steam emerging from the valve, she will let loose of it and the valve will return to normal position and function properly as a safety valve.

Referring now to the drawings in more detail. In Fig. l, I represents the central section of the cover of a pressure cooker and into which a valve stem 2 is threaded. The valve stem 2, which is generally cylindrical in shape, projects upwardly from the upper surface of the cover I and contains a central opening 3 extending from end to end of the stem and a-round the upper end of which a valve seat is located. The outer surface of the stem has a taperedend portion 4 and a groove 5 for apurpose which will hereinafter appear. Projecting through the stem at a point below the groove 5 is a pin 6.

Fitted overthe stem isa cuplike member or housing In having an annular cavity H opening into its upper edge. Centrally located in this cavity is a boss it through which is threaded a screw l3, the lower end of which carries a generally conical valve member H which projects into the stem and engages the valve seat therein to seal the pressure cooker.

In the operation of the pressure cooker, after the cover has been placed on the vessel, knob I! is turned to unscrew the screw [3, thereby drawing the valve member l4 back into the boss l2 the housing. This lowers the housing with respect to the valve stem 2, the pin 6 engaging the bottom of the grooves 21a to support the housing on the valve stem with the valve open. Heat is applied to the cooker and as the water therein starts to boil air is driven from the cooker and steam starts to escape through-the valve. The housing In is provided with a plu- 4 rality of downwardly extending ports 22 leading from the upper end of the counterbore and through which steam escaping through the valve stem 2 can escape from the housing H). These ports are positioned so that this steam is directed down onto the top of the cover.

As soon as steam flows freely from the cooker, knob I1 is operated to rotate the screw in a clockwise direction (Fig. 2"), thereby moving the valve element l4 downwardly into engagement with the valve seat in the stem. Further movement of the screw in this direction raises the housing [0 and with it the weights l5 so that all are supported on the stem of the valve member l4.

soon as the screw has been operated far enough to support the valve assembly on the vmember l4, and not on the pin 6, the safety valve"is in operation; however, most probably the housewife will continue to operate the screw until the disc-like portion l6 of the knob firmly engages the top of the housing l0. Such continued movement will eventually place on the housing a torque greater than the weight of the valve assembly, with the result that the pin 6 will ride over the inclined surface of the groove 2 la and raise the housing so as to open the valve. Groove 5 is sufiiciently wide so that thislimited movement of the assembly takes place before the spring 20 engages the upper edge of the groove. Should the parts become worn, or for any other reason the spring should engage this edge of the groove and become jammed thereag ainst, the safety valve will not return to normal and the cooker will not be sealed so that pressure cannot be built up in it.

After the pressure within the cooker has been built up to the desired value, which in the example shown and with both weights IS in place in the housing will be fifteen pounds per square inch, the weight of the valve assembly is insufiicient to hold the valve member M on the seat against the pressure working on the under surface of this member M, with the result that the valve will be opened and excess steam allowed to escape. As soon as this escape of steam occurs, the operator knows that the cooker is up to pressure and the heat is then reduced to just maintain that pressure during the cooking period.

As soon as the cooking period has elapsed and it is desired to open the cooker, it is removed from the heat or the heat extinguished, and knob I"l operated in a counter-clockwise direction (Fig. 2) to back the screw l3 upwardly into the housing thereby opening the valve by backing the member l4 away from the valve seat. A slight opening of the valve permits escape of the steam, and after the pressure has died down somewhat the valve may be further opened andthe steam allowed to escape more rapidly until the pressure in the vessel is reduced to Zero or practically zero, at which time the cover may be removed with safety.

When"the cover is removed, steam will be condensed on the under surface of it, and in order to retain the drops of water thus formed in the cover it is natural for the housewife to turn the cover upside down. Spring 20 engaging the upper surface of the groove 5 retains the valve assembly on the stem, the tension of the spring being sufficiently great that even though the cover be handled rather roughly the valve assembly will not fall off of the stem; howeven.

from the cooker for cleaning or any other purpose, a slight pull on the housing in will disengage the same from the stem. The inclined upper surface 4 of the stem facilitates replacement of the valve assembly thereon as desired.

In Figs. 1, 2, and 3, rotation of the valve assembly with respect to the stem is prevented by the pin which projects through the stem and across the central opening therein. In certain instances, the presence of this "pin in the port may be objectionable, and in those cases the valve stems shown in Figs. 4 and may be employed. This stem is the same as stem 2, having the inclined upper surface 4 and the groove 5, and having also an annular shoulder 30 and a cylindrical shoulder 3! against which a washer-like annulus 32 is fitted and held in any preferred manner such as by stakes 33. Projecting upwardly from the outer edge of the annulus 32 are ears 34 which lay along the outersurface of the stem and fit into the groove 2 la in the housing, in lieu of the projecting ends of the pins 6. The central port 3 in the stem is free and clear of obstructions of any kind, and the operation of the valve assembly is the same as hereinbefore described.

In the cooking of certain materials, apples for example, when the saftey valve operates and reduces the pressure in the cooker, the apples will more or less explode and oftentimes a piece of skin will be blown up against the bottom of the valve stem 2. To prevent the blocking of this stem under such circumstances, the lower end is provided with side opening ports 35 through which the pressure can escape even though a piece of material lays across and completely blocks the bottom opening therein.

The saftey-release valve of my invention is possessed of many advantages. It may be manufactured economically without sacrificing quality. It is securely held on the valve stem so as to minimize damage due to the valve falling off of the cover. Each time the valve is operated manually, the automatic operation is checked so as to insure that the safety valve is in proper working order at all times while pressure is being built up in the cooker. Maximum pressure could be varied by taking out one or both of the weights so that pressures of five, ten, or fifteen pounds can be realized.

1. In a safety valve for pressure cookers, a generally cylindrical body having a concentrically located threaded opening; a screw threaded through said opening; a knob fixed on the upper end of said screw and disposed above said body; a valve element formed on the lower end of said screw; a counterbore in the bottom of said body located concentrically of said threaded opening; a generally cylindrical valve stem projecting into said counterbore and having a concentrically located cylindrical opening; a valve seat on the upper end of said valve stem around said opening, said valve element engaging said valve seat to support said body, screw and knob on said stem and to seal said valve 6 stem opening against predetermined pressure, there being grooves in the bottom of said body extending radially outwardly from said counterbore; means on said valve stem projecting into said grooves; and a radial wall at one end of each groove moved into engagement with said means by a counterclockwise rotation of said knob, screw and body to stop the rotation of the body so that further rotation of the screw will lower the body onto said means and then raise said valve element off of said valve seat to vent said valve stem opening.

2. In a safety valve for pressure cookers, a generally cylindrical cuplike member having a cavity opening into its upper end, a cylindrical boss concentrically located in said cavity, annular weights disposed in said cavity and surrounding said boss, a screw threaded through said boss, a knob on said screw extending across the open end ofsaid cavity to hold said weights therein, a counterbore located concentrically in the bottom of said cuplike member into which said screw projects, a shoulder in said counterbore, a spring disposed in juxtaposition to said shoulder, an annulus pressed into said counterbore and against said spring to hold the spring in the counterbore, a generally cylindricalvalve stem having a concentric central opening, a valve seat surrounding said opening at the upper" end of said stem, a valve head on said screw engaging said seat to seal the stem against a predetermined pressure, said valve stem projecting into the counterbore and having a groove into which the spring extends to hold the cuplike member on the stem, said groove being wider than the spring is thick to permit limited movement of the member axially along the stem, said annulus having radially disposed grooves in its lower surface, and means carried by the stem and projecting into said grooves to prevent rotation of the cuplike member around the stem.

3. In a safety valve for pressure cookers, a generally cylindrical body having a concentrically located threaded opening; a screw threaded in said opening; a knob fixed on the upper end of said screw and disposed above said body; a valve element formed on the lower end of said screw; a counterbore in the bottom of said body located concentrically of said threaded opening; a generally cylindrical valve stem projecting into said counterbore and having a concentrically located cylindrical opening; a valve seat on the upper end of said valve stem around said opening, said body having grooves in its bottom surface extending radially outwardly from said counterbore; means on said valve stem projecting into said grooves and engaging the tops thereof to support the body, screwand knob on the stem, said screw advancing through said threaded opening as the knob is turned clockwise to engage said valve element with said valve seat and then to raise said body off of said means thereby to seal said valve stem opening against predetermined pressure; and an inclined wall at one end of each groove rotated into engagement with said means and riding over the same to raise the body screw and valve element thereby to break said seal when said clockwise rotation of the knob is continued after the seal is formed.

4. A safety-release valve as set out in claim 3, in which the means carried by the valve stem consists of a pin extending through the valve stem and projecting radially therefrom into said grooves.

5. A safety-release valve as set out in claim 3, UNITED STATES PATENTS in which the means carried by the valve stem Number Nkmme Date consists of a collar encircling the stem and 853,131 Aichele June 25, 1907 fixed thereto and having earlike projections ex- 1 337 Hashimoto Dec. 1, 1931 tending radially outwardly into said grooves. 5 23O8320 Stephens Jan 12 1943 6. A safety-release valve as set out in claim 3, v in which the slope of the inclined surfaces FOREIGN PATENTS bounding the groove in the cap forms an angle Number C t t of approximately 45 so that torque placed on 4,031 Great Britain s 1-, 22, 1331 the screw and cap will have a substantial com- 10 230,049 Switzerland Dec 15, 1943 ponent along the axis of the valve stem and cap.

Pressure cookers are fantastic tools. They develop the characteristic flavors and textures of foods so quickly that what is conventionally a long, labor-intensive process becomes one hardly more time-consuming than a casual sauté. Risotto takes six minutes instead of 25. An intense chicken stock takes only 90 minutes. You can even pressure-cook food in canning jars or in oven bags or FoodSaver bags rated for high temperatures–which means grits and polenta, for example, no longer require constant stirring to avoid sticking. The high temperatures inside the cooker also promote browning and caramelization, reactions that create flavors you can’t get otherwise in a moist cooking environment. If you aren’t a believer, try our Caramelized Carrot Soup recipe.

A pressure cookeris essentially just a pot with a semi-sealed lockable lid and a valve that controls the pressure inside. It works by capturing the steam that, as it builds up, increases the pressure in the vessel. The pressure increase in turn raises the boiling point of water, which normally limits the cooking temperature of wet foods to 100 °C / 212 °F (at sea level; the boiling point is slightly lower at higher elevations). Because the effective cooking temperature is higher in the pressure cooker — as high as 120 °C / 250 °F — the cooking time can drop substantially.

A spring-loaded valve is normally open so that air can escape. As heating begins, expanding vapor pushes this valve up, closing off the vent. (At very high pressures, it rises farther and reopens the vent to release excess steam.) The valve regulates the pressure inside the cooker to a preset level: typically 0.7 or 1 bar / 10 or 15 psi above atmospheric pressure; this value is called the gauge pressure. At these elevated pressures, water boils at 114 °C or 121 °C / 237 °F or 250 °F, respectively. As soon as the cooker reaches the correct cooking pressure, reduce the heat to avoid over-pressurizing it.

The sealing ring, typically a rubber gasket, prevents steam and air from escaping as they expand. This causes the pressure in the vessel to build as the temperature rises. Any food particles stuck in the seal can cause it to leak steam, so check and clean the gasket regularly.

The lid locks with a bayonet-style mechanism that pushes against the sides of the cooker. Frequent over-pressurization can damage this mechanism and render the cooker useless. Other designs use bolts that clamp around the outside.

Water vaporizes into steam, increasing the pressure inside the cooker as it heats. Because the boiling point of water depends on pressure, it rises too, just enough to keep the water and steam temperature hovering around the boiling point for the higher pressure. The pressure continues to rise until it is stabilized by the valve.

Quick pressure release or natural pressure release?It’s one of the most common questions I get. Electric pressure cookers and multi-cookers like the Instant Pot, Ninja Foodi, and Crockpot Express have the ability to release pressure two ways. Instant Pot Natural Release is a frequent search term. Let me explain the difference!

Releasing the pressure can be a little intimidating to people who are new to pressure cooking—especially the quick release with the noise and jet of steam. But don’t let a little noise get between you and fabulous meals cooked in your pressure cooker!

Those are often the first questions new pressure cooker users ask. So I thought it would be a perfect time for a post explaining it for all those who have an electric pressure cooker or multi-cooker like the Instant Pot waiting for them under the tree.

When the cook time ends, your pressure cooker will beep. At this point, the recipe will direct you to release the pressure in the cooking pot. You can release the pressure two ways: a quick pressure release or a natural pressure release.

A quick pressure release is when you turn the pressure release switch to the Venting position and let the steam to release quickly when the cook time ends. This will result in a strong jet of steam coming from the pressure release valve. This is normal.If drops of liquid or foam start to emerge from the pressure release valve, simply switch the valve back to the Sealed position and use an Intermittent Pressure Release (more on that below).

Other pressure cookers may have different labels, but it’s the same basic principle. Turn the valve to allow the steam to escape / pressure to release.

When the pressure is fully released, the float valve will drop and the lid will unlock to open. For safety reasons, the pressure cooker will not open until the pressure is released and the float valve has dropped.

Using a quick pressure release stops the pressure cooking quickly. Therefore, you should use a quick pressure release when you are cooking ingredients, like vegetables, that you want to avoid overcooking.

A natural pressure release is when you leave the pressure release switch in the Sealed position when the cook time ends. This lets the pressure release slowly, without you doing anything. When the pressure is fully released, the float valve will drop and the lid will unlock and open.

A natural pressure release is a bit anticlimactic in comparison to a quick pressure release. There is no jet of steam when the natural pressure release starts. There’s also no clear way to tell when the pressure is fully released, and no beep or signal when the lid unlocks. Sometimes you can hear the float valve drop if you’re close by.

The time it takes for the pressure to release naturally will vary depending on the ingredients and amount of liquid in the pressure cooker. A natural pressure release can take from 5 to 30 minutes in the electric pressure cooker.

Using a natural pressure release allows the cooking to stop gradually. You don’t want to open the valve quickly when the ingredients inside could be foaming. You’ll get foam shooting out through the valve, so use a natural pressure release when making steel cut oats, a large pot of soup or pasta.

The different types of pressure releases can also be combined. You don’t have to wait for all the pressure to release to get the benefit of a natural pressure release.

I almost always only wait 10 minutes before I release the remaining pressure. Combining the two release options reduces waiting time yet gives you many of the benefits of a natural pressure release, such as reducing foam and tenderizing meats.

An intermittent pressure release is the best of both worlds. It’s a way to quickly release pressure for foods such as pastas, soups, and certain grains, which are prone to foaming or spitting if you try to release pressure with a quick release but would be overcooked with a natural pressure release.

With this method, you open and close the pressure release valve in short intervals. This allows the pressure to escape more quickly than a natural pressure release and also prevents foam from coming out of the pressure release valve.

With some foods, one or two closed intervals is all I need before I can leave the valve in the Venting position; with other foods, if the foaming is particularly bad, I will close the valve and wait a minute or two, then slide the valve to Venting again and continue opening and closing the valve as needed.

No you do not need to turn the pressure cooker off for a quick or natural pressure release. The pressure will release on the Keep Warm setting. The benefit of not turning it off is that the time will count up so you can see how long it’s been since the pressure cooking time ended.

There is some debate about whether or not the pressure releases more slowly if it’s on the Keep Warm Setting. The Instant Pot Company’s official position is that it does not release more slowly on the Keep Warm Setting because the Keep Warm heat does not turn on until the pressure has been released.

I prefer to turn off or unplug the pressure cooker before I do a quick pressure release or natural pressure release. I seem to always forget to turn off the pressure cooker if I don’t turn it off when the pressure cooking ends. I also prefer to set a timer to remind me 10 minutes has passed and it’s time to release the pressure when I’m doing a natural pressure release.

Once you have your first meal under your belt, move on to some easy pressure cooking recipes. Before you know it, you’ll be making fabulous pressure cooker meals and wondering how you ever cooked without it.

Pressure cookers are quite common in kitchens these days because they save time and effort while in cooking. They used to be dangerous, but not anymore, thanks to improved technology, advanced mechanisms, and safety features that have given an entirely new dimension to cooking.

However, like every other tool, a pressure cooker can encounter issues that can impact the cooking time and the quality of food, causing you unnecessary frustration. What would you likely do? Check the instruction manual and search for troubleshooting steps.At times, user manuals may not be able to resolve the problem, because of the following reasons:

This is the main reason why this particular post includes every problem a pressure cooker can develop. Starting with the basic steps on how a pressure cooker should be used, we’ll take you through the common functioning issues, followed by some critical ones. This post will provide the insight on technical and functional aspects of modern-day pressure cookers. So, let’s get started right now!

Below are the steps showing how you should operate your pressure cooker under normal circumstances.Pour the liquid into the pressure cooker up to the minimum level indicated in the manual. Add the desired food item and lock the lid if required.

Choose the pressure according to the food (normally indicated in the manual). Modern-day pressure cookers, especially electric cookers have pre-determined programs and time. So, you can use this feature as well.

After 10 to 15 minutes of pressure cooking, the following processes will have taken place:The air and steam will escape out of the valve indicating that the cooking contents are boiling.

You have to turn on the digital timer to cook the food at the desired pressure. In automatic electric pressure cookers, there is a count-down feature that automatically maintains the pressure for a certain time.

At the end of the cooking, the pressure release takes place. It depends on upon the recipe what kind of pressure release method suits it. The pressure releases as the steam comes out through the pressure release valve.

Steam leakage is the most common problem in pressure cookers that causes problems in pressure buildup. It takes longer for the pressure to reach the desired limit, and when it does, it cannot remain constant for the specified period.

Wash the gasket in cold water and fix it back in the correct manner. Follow the directions while fixing the gasket back to its position.Damaged Gasket or Old Valve

Sometimes the gasket gets damaged. With the passage of time, the pressure valve loses its efficiency and effectiveness. As a result, you don’t get the right pressure buildup for cooking.Always check the gasket and pressure valve for damages, and replace them as soon as possible.

There are several different issues why your pressure cooker may not properly cook the food within the estimated time, such as:You’ve filled too much food or water

If you’re a new user, you might easily be scared seeing water coming out of the valve, but it’s not a big thing. However, this is another common issue that can cause operational issues for a pressure cooker.

This particular problem mainly occurs in pressure cookers that have pressure regulating weights. You can see the water dripping out and vapors accumulating around the rim during the pressure buildup. As soon as the pressure is achieved, the vapors go away.

Anyhow, if you have a different model and still having the same issue, it may be because of food particles accumulated inside the vent pipe. To avoid this issue, clean the valves and the vent pipe regularly.Difficulty in Opening the Lid

Another common problem with pressure cookers is, the cooker lid gets tight and remains jammed even after the heat is turned off. It is often caused by the internal pressure of the pressure cooker. The pressure release may be insufficient and ends up jamming the lid.

If the lid remains jammed, remove the pressure valve and allow the pressure cooker to heat on high. That will release the pressure, and the lid will loosen its grip.

There are many reasons for pressure cookers not achieving the desired pressure level. Each of them, with their solutions, is mentioned below:The Lid: The lid of the cooker must be positioned accurately. In that case, remove and refix it in the right manner. If the problem persists, replace the lid according to the instruction manual.

The Gasket: There may be a problem with the gasket’s positioning. You need to remove the gasket by removing the lid first. Clean the gasket properly then refix it in the manner specified by the instruction manual. The gasket may deteriorate with excessive cooking, spattering oil, and acid foods. If there are signs of wear, a replacement may be needed.

The Locking Mechanism: Pressure cooker may not be attaining the right pressure because of the locking mechanism. Or, it may not have been locked properly. This problem occurs in pressure cookers that do not have a self-locking feature. Check the locking mechanism of your pressure cooker, thoroughly before putting the food in it.

The Rim: Leakage may also occur due to a damaged rim. They get damaged when you rap your spoon against the rim. If you have a stainless steel pressure cooker, use steel wool to remove scratches and stains on the rim.

The Valve: Another reason why the specified pressure level is unattainable is due to the improper placement of the pressure valve. Improper cleaning of the valve causes this. So, always clean and fix the valve of the pressure cooker before cooking.

Old Gasket and Valve: As discussed above, the gasket and pressure valve must be checked regularly before using the cooker. Normally, you should replace the gasket and other pressure cooker components made of silicone or rubber every 18 months.

The Liquid: Pressure cookers have limited capacity for food, and they always need space to build pressure. A pressure buildup will take up to 30 minutes to reach the desired pressure if there is too much liquid inside the cooking pot. Follow the instructions while adding the liquid to keep it at the minimum level.

The Food: Normally, the instruction manual has information about how much ingredients you can put inside your pressure cooker for a certain recipe. Too much ingredients can cause a delay in pressure buildup, or the pressure may not be achieved at all. In general, if you’re filling grains, fruits, and legumes, keep your pressure cooker half-full. For all other recipes, maintain 2/3 of the filled space.

Cold Items: Either allow the frozen food to defrost before pressure cooking or plan for longer times. Frozen ingredients can easily increase the pressure cooking time up to 30 minutes.Desired Pressure Cannot be Maintained

Any of the following issues may cause difficulty maintaining the pressure you want:Old or Damaged Gasket: The gasket of the pressure cooker needs to be replaced every 18 months. If your pressure cooker consists of other rubber or silicone parts, replace them periodically.

Problem with the Valve: Pressure valve needs to be secured properly to create pressure buildup and maintain the desired pressure for a certain period of time. Pressure cannot reach the desired level with an old or worn out pressure valve. So, always clean the pressure valve and replace it every 18 months.

External Temperature:This is the main issue with stove top pressure cookers in which you either reduce the heat too much or too soon. Read the instruction manual thoroughly to know the exact time to turn down the heat. If you think you’ve turned the flame lower than the required limit, turn it back to high and allow the pressure to build. Then reduce the heat slowly to the desired level.Pressure Valve Sprays Foam or Food

It can happen because of the following reasons.The opening method: The main reason why a pressure valve sprays foam, you’ve used the wrong opening method. If it sprays foam, there is likely legumes, fruits, and grains in the pressure cooker. For these ingredients, the only way to open the pressure cooker is through natural release method. For other recipes, follow the instruction manual.

Thickeners: If you have included thick liquid or flour in your recipe, the pressure valve may spray the food out. It happens because of the food binding with the steam, and when the pressure is released, some food particles might also come out.

Filling More than Limit: If the pressure cooker is filled more than its capacity, food particles will mix with the steam and spray out when the pressure is released. So, keep the pressure cooker 1/3 empty for all kinds of foods except for fruits, legumes, and grains as they should half-fill the cooker.Pressure Cooker Releases Steam More than it Normally Does

Steam is released before pressure cooking and after it… there are few reasons why your pressure cooker releases too much steam in either stage.Valve adjustment: If you notice that the valve is releasing too much steam, adjust the valve.

Too Much Heat: Excessive heat applied to the pressure cooker may cause too much steam release. In that case, let some pressure out then reduce the heat.Food is not Cooked Properly

Your food may be undercooked or overcooked because of the timing, regardless of the model you use. Follow the instruction manual and note the amount of time required for different recipes to cook properly. There may be other reasons as well.Heat During Pressure Cooking: In stovetop pressure cookers, if you set the heat too high, the food can be overcooked, dried, or burned. Too much heat builds up extra pressure and causes the food to burn or dry. So, if you experience it during cooking, lower the heat to the minimum level.

Burner Size: Another problem with stovetop pressure cookers is, if the burner is wider than the size of the pressure cooker, your food may overcook or burn. Always, use the burner according to the size of your pressure cooker.

Well, if you have installed a new gasket then you have to make sure it’s installed the right way. While installing it in the lid, make sure that the “Right Side” of the gasket points upward. If the problem persists, check the structure of your pressure cooker looking for signs of “warping”.

If you have a vintage aluminum pressure cooker, it may have this problem. Stainless steel pressure cookers don’t often face this issue, and they don’t damage as often when compared to their aluminum counterparts.It may have a warped lid: you may not detect the warping at first sight, but even the slightest warping can cause the steam to leak. It may have been due to overheating or aging of the material. Or, the pressure cooker may have been dropped in past.

The base unit has a damaged rim: This is caused by dents, dings, scratches and abrasive cleaners. If the rim gets damaged, it may not allow adequate sealing. In this situation, you have to either replace these parts or buy a new pressure cooker.Gasket Stuck to the Lid

The metal sealing and the pressure cooker lid should not be scratched or damaged while removing the gasket. So, avoid using scrapers, sandpaper, or abrasives on these metal surfaces.Aluminum Pressure Cooker Having Stains

If you have an aluminum pressure cooker, you have to be careful while cleaning it. Alkali solutions can harm and discolor aluminum. Baking soda is a mild alkali and ammonia solvents are medium strength alkalies that can cause stains on aluminum pressure cookers. You can remove light stains and small discoloration by cooking acid foods in an aluminum pressure cooker. For stubborn stains, you can apply the following method.

If you live in a location where tap water contains minerals, your aluminum pressure cooker may develop mineral stains. That happens, because the minerals from the water deposited inside the aluminum pan, react with the soap, detergents and the fats from the food and produce stains on the surface.

Heat tint is a dark and permanent discoloration on stainless steel with purple or blue color appearing prominently. It is caused by any of the following issues:Too much heat is applied to the pressure cooker

Although the heat tint is permanent, it may fade with the passage of time. Mild discoloration does not affect the usefulness of the pot, while severe tints can cause functional issues in your pressure cooker.

Our, inventionrelates. to safety valves, and .has particular reference to safety valves for pressure cookers, particularly of.the type used for home cooking, food articles.

Pressure cookers are usually provided with safety valves.. Because of the presence of solid matterin-the food.being cooked, the valves often become clogged and inoperative. To prevent the possibility-.of an explosion, a safety blow-out plug is. also usually, provided, which releases the. steam when. pressure rises above the blow-off: pressure of the.safety valve... Such blow-out plugs have a. disadvantage. in. that- they must be replaced after. each operation; also that their operation results. in a blast of .hot steam upward from the cooker with a resultant danger of scalding attendant"s face and: hands. The same difficulty is often .encountered with the conventional safety valves which exhaust steam directly.upward.

Our. inventionhas. for its object to provide a safety valve for a pressure. cooker which is so constructed that the blow-off steam. escapes in a direction tangential to the cover of the cooker so that the danger of scalding one"s hands or face is. practically, eliminated..

Another object of our invention is to provide a safety valve for a pressure cooker so constructed that it cleans itself when it is operated, by removing any obstructions which may accumulate at the intake of the valve.

Another object of our invention is to provide a safety valve, which can be easily removed for cleaning or replacement but which is provided with a locking mechanism for preventing the valve from working itself loose or from being accidentally removed.

Another object of our.invention is to provide a locking means for our safety valve whereby the valve can be locked in.an open position, when it is desired"to cook at-the atmospheric pressure.

Still.another object of our invention is to provide a supplementary safety, valve constructed ih conjunction with the foregoing safety valve and so arranged that it opens at a pressure substantially higher than, the, blow-off pressure of the main safety valve, being held closed by an adjustable spring and having a relatively large opening whiCh cannot be clogged by food particles.

The. foregoing and other objects; features and sdvarntiages" are" more ftlly: described- in the accomanuying,specificatiori andth"dra"wing in which; Fig. 1 is a sectional elevational view of our safety valve in conjunction with supplementary safety valve, the main valve being shown in. an open or inoperative position.

Fig. 2 is a detail view of the removable portion of the valve; Fig. 3 is a top plan view of the valve removable portion; Fig. 4 is a top plan view of the fixed portion !o of the valve; Fig. 5 is a sectional elevational view. of a pressure cooker with our valve shown in. a reduced scale; Fig. 6 is.a sectional elevational view of a simplified valve.

Our safety valve in its form shown in Fig, 1 consists of a disc-shaped base I having a stem or extension 2.threaded at 3 into a convex plate 4. The latter is placed on the outer side of a cover or lid 5 of a pressure cooker 6 as shown in Fig. 5. The cap 4 covers a large opening 10 in the lid 5 and is provided with a gasket: I made of rubber or similar material providing a steamproof seal. The lower end of the extension 2 2 passes through a corresponding opening in a spring plate 12 and is tightened by a nut 131 The plate 12 is curved upward and its ends rest against the under side of the lid 5. By tightening the nut 13. the plate 12 is placed under compression, causing the plate 4 to be tightly pressed against the outer side of the lid 5.

The extension 2 of the base I has a central bore 14 with a tapering valve seat" 1"5 at the lower end of valve 18. The latter has a stem- 9 -passing to the outside of the base I and sliding in a corresponding hole in a cap 20. The latter is threaded at 21 on an upper extension 22 of the base I. The lower portion of the cap is round and is confined within upstanding flange 23- of the base I; A helical spring 25 is placed on-the stem 19 between the valve 18 and the upper portion of the cap 20. The pressure of-the spring 25 determines the vapor pressure in the, cooker at which the valve 18 is raised from its seat I . This pressure can be adjusted by turning the cap 20 to the right or to the left. thereby moving the cap up or down on the threads 21. Each particular position of the cap 20 corresponds to a-definite vapor pressure, which is marked on the cap-by numbers 26:with reference to a stationary mark 27 on the flange 23.

To prevent accidental removal of the- cap 20, it is provided with a locking plunger- 30 slidably fitted in a bore- 31 of the cap and provided with a pin 32 at the bottom engaging- an- arcuate groove 3S in the upper surface of the base I. A stem $3 extends from the plunger and passes through a corresponding hole in the upper clozed end of the bore. A nut 35 is threaded on the upper outer end of the stem 34 and relates the plunger in its place when the cap with the valve is removed from the base I as shown in Fig. 2. A spring 3G on the stem 34 urges the plunger 30 downward. The groove 33 extends through a substantial portion of a circle so as to make it 0 possible to adjust the position of the cap 20 to a desired vapor pressure. The groove 33 also prevents the complete unscrewing of the cap, shoulders 37 at the ends of the groove 33 engaging the pin 32.

The valve 18 is provided with a pin 40 at the lower end, passing with a clearance through the bottom hole 41 in the valve seat. The pin extends beyond the end of the hole 41 so that the pin, when the valve is raised and seated again, will clear the hole 41 from any obstruction or clogging caused by solid food particles.

Blow-off holes 38 extend radially and horizontally through the walls of the extension 2 for releasing the vapors escaping through the valve. The base I has a depending flange 39 at the periphery for breaking the vapor flow from the holes 38 thereby protecting the attendant from the vapor.

For lowering the valve in an open position when it is desired to cook at the atmospheric pressure, a lowering hook 46 is provided at the end of the valve stem 19, one end of the hook rotatively engaging the hole at the stem. By turning the hook in a vertical position as shown in Fig. 1, the valve stem is raised, leaving the valve open. The valve is released when the hook is turned to the side as shown in Fig. 6. " Despite all precautions, however, the valve may be temporarily clogged thereby causing the vapor pressure to rise above the desired value.

To prevent the possibility of an explosion, a second safety feature is provided consisting of the above described cover plate 4 and spring plate or bar 12 to which the lower end of the extension 2 is secured by the nut 13. The tension of the spring plate 12 is so adjusted that the plate will yield when the total vapor pressure on the " cover plate 4 exceeds a predetermined value, usually substantially higher than the corresponding vapor pressure to which the cap 20 was set. Beca