In detail: DIY repair of a cork valve from a real master for the site my.housecope.com.
How does a cone (cork) valve work? Where are these products used? What, for example, is a cork valve 11B6BK DU50 used for? How good are these elements of valves in water supply and heating systems against the background of alternatives? Let's try to answer these questions.
This is the name of a closing or regulating device, the main element of which - a plug - has the shape of a full or truncated cone with a through channel and is in contact with the body with all lateral surfaces. Impermeability to water, air, gas or other medium transported by the pipeline is ensured by the absence of a gap between the walls of the housing and the plug.
The design of a plug valve implies a large friction area and, as a result, a large hardening required for turning. Of course, with a huge pipeline diameter, it will become unacceptably huge; in addition: the adhesion of surfaces will additionally increase the resistance.
It is on this basis that corrosion-resistant materials with a low coefficient of friction - brass and cast iron - are traditionally used for the manufacture of cork valves.
Please note: due to the peculiarities of the design and the low mechanical strength of the metals used, the diameter of cork valves rarely exceeds 100 mm, and the working pressure is 16 atmospheres.
There are no rules without exceptions: if you are thirsty for sale, it is possible to find a cork straight-through valve with a diameter of up to 200 millimeters in a metal case.
But to those valves that can be found in basements, it has little to do with:
To facilitate the rotation of the plug, a gearbox with a steering wheel is used.
The plug is still made of cast iron: if two metal elements stick to each other, the gearbox will not help to tear them apart.
Video (click to play).
It is not difficult to realize how the tap shuts off the movement of water or gas in the pipeline. How exactly is it ensured that there is no leakage to the environment?
The plug passes through the valve body completely. Its threaded shank, when tightening the nut screwed on it, presses the plug against the body with greater hardening. The gap-free design ensures that there is no leakage through the valve in the pipeline or into the environment.
Curious: when the valve is operating, the level of quality of grinding surfaces improves over time.
The gas plug cone valve, which can be seen on the supply line to the gas stove in most Russian apartments, is arranged in a pair otherwise: the plug is pressed to the body not by a nut, but by a spring. Small hold-down hardening coupled with lubricant provides moderate plug rotation hardening; but the high working pressure of the structure is more than small.
Finally, for water supply and heating, a plug-gland valve was massively used: the gland packing near the stem ensured the absence of leaks. In most cases, a braided graphite gland was used.
How the packing was clamped in most cases depended on the valve material:
Brass products were crimped with a union nut.
A cork cast-iron crane often used several bolts to crimp the gland, which pulled the gland to the lugs of the body.
Flanged... Adjacent flanges are pulled together by four to eight bolts; tightness is ensured by a paronite or rubber gasket.
Threaded or coupling... Plumbing linen and unnatural sealing materials are used for sealing.
Depending on the nominal diameter of the connected pipeline, the DN (nominal bore) of the valve is indicated. Domestic documentation uses the metric system; DN corresponds approximately to the inner diameter of the pipeline in millimeters. Imported goods are more often labeled in inches:
Here are a couple of examples of the use of cork valves in different designs.
The most vivid example is a samovar faucet. The plug in it is held in the valve body only by its own weight.
Mixers of the Soviet example with a lever switch were not very ergonomic in use and often leaked; but they were virtually indestructible. Breaking a lever or a plug was not an easy task.
Three-way cork taps were used to regulate the temperature in apartments: depending on the position, they let the coolant flow through the battery, through the jumper, or completely blocked it.
By the way: the last function of the crane was a circumstance of the fierce hostility of the locksmiths who served the areas built up by the Khrushchevs. Finding out which of the tenants turned off the tap on the riser was far from straightforward.
We have already mentioned gas taps of the Soviet example. The plug valve, against the background of the then widespread screw valves, really looked much more reliable and ensuring that there were no leaks.
Finally, along with the screw valve, a plug stuffing box valve was the most common element of shut-off water supply to heating systems and fittings in the 60s - 80s of the last century. It was there, for example, that the 11B6BK DU50 valve mentioned at the beginning of our material was massively used: it was mounted on the hot water and heating insets in the elevator nodes.
What do cork taps look like when compared to alternatives for plumbing?
Let's start by praising them.
Unlike screw valves, they do not need to be oriented in some way in the direction of the water flow. The valve breakage is not easily threatened due to its absence.
A straight and wide through channel in the plug forms a fairly moderate hydraulic resistance - again, in contrast to the meandering strokes in a screw valve.
For the same reason, plug valves will never become clogged with scale, rust and sand under any circumstances. Garbage simply has nowhere to stay in them.
Cork valves compare favorably with modern ball valves in higher resistance to high temperatures.
But: 150 C, which is large for a ball valve, is the temperature limit on the supply line of the heating main during the peak of winter cold weather. Higher values are achievable only in steam heating systems, which are currently used only by a few industrial companies.
The author's experience of communicating with plug valves in water supply and heating systems makes it possible to formulate the following main claims to them:
Both cast iron and brass valves boil with long inactivity. In order to crank them at the end of five years of inactivity, hardening is required, fully talented to break the threads on the drive.
At the end of the notorious period of inactivity, the smallest turn of the valve leads to water leakage through the gland. Yes, this is a nuisance - non-specialized for all stuffing box products; but with a screw valve, it is solved by its complete opening. Immediately you have to fill the oil seal again.
By the way, about the oil seal: it is possible to fill it only by first shutting off and throwing off the water. What is the instruction related to? If you open the valve under pressure, the disturbed plug will quite possibly fly in your face at the front of the water flow. At best, cold, at worst, scalding hot.
For comparison: a valve with ground-in cheeks for stuffing the gland with your own hands is enough.
Sealless (tension) valves have to be loosened before opening or closing, which is accompanied by water leakage.Especially touching when you are under the valve. If, however, do not loosen the tension nut, there is a real chance of tearing off the thread from the plug.
The stem for turning has to be taken with an adjustable, open-end or (much more often) a gas wrench. As a result, quite often used valves can be easily identified by the rods that are rounded or even virtually absent above the stuffing box.
With all that, the price of a plug valve is not lower, but usually higher than a ball valve of the same size.
The conclusions are rather disappointing. The obsolete design has already lost the battle for the plumbing communications market and can only be used in highly specialized industrial pipelines.
In buildings where there is a three-way plug valve under the radiator, it is only possible to recommend replacing the connections as soon as possible.
As always, in the video in this article, the reader will be able to find additional thematic data. Good luck!
Probably, each of us should know how to fix a water tap. Moreover, in most cases, the malfunction can be eliminated fairly quickly and at no extra cost, but the call of the master should be expected for more than one hour, and he will take a lot of money for the work.
In our article, we will tell you about the most common breakdowns of water taps, after which we will provide repair algorithms for most models.
With experience and skills, any malfunction can be quickly eliminated
Before you repair a faucet mixer, you should take the time to analyze the situation. This way we can understand exactly what actions are worth taking, thereby saving a lot of time.
Leakage is the most common problem
The list of breakdowns includes the following items:
In principle, this table describes the main faults. Other situations that may arise during the operation of the crane are derived from those already analyzed, and therefore they need to be repaired according to a similar algorithm.
But such cracks cannot be repaired.
Also, before starting work, you should carefully familiarize yourself with the design features of the model you have installed. As a rule, an assembly drawing of a faucet comes with the product itself, therefore, when installing a new faucet, this document should be saved.
Note! If you can't find the diagram, then you should enter the query "assembly drawing method for indicating the water tap" in the search engine and select your model. Most manufacturers put their technical documentation online, so the chances of finding what you need is very high.
Now we will try to figure out what to do in each specific case. And let's start with the most common situation, namely, with the elimination of the causes of leakage of the shut-off element.
Drawing of the body of the faucet and a schematic representation of the shut-off elements
Cranes, in which an axle box acts as a shut-off valve, are the easiest to repair.
The algorithm of actions here is as follows:
Before disassembling the water tap, be sure to shut off the water on the riser.
Remove the lining from the flywheel, under which the fixing screw is located.
Unscrew the screw using a screwdriver, then remove the flywheel from the guides.
Removing decorative cones, covering the place of attachment of the axlebox.
Using an adjustable wrench, unscrew the worn-out axle box from the socket... We clean the cavity from sediment and blot it with a rag, removing the remaining water.
We install in place a new axle boxscrewing it along the thread. In this case, you do not need to make unnecessary efforts so as not to damage the structure.
Next, we need to check the valve for leaks.... We turn on the water on the riser and inspect the place where the axle box is installed.
Grabbing the stock with pliers, we turn it several times... The flow of water must be switched on and off quickly and clearly.
We carry out the assembly in the reverse orderby installing decorative cones and securing the flywheel to the crane.
In some cases, crane axle boxes can be repaired. It all depends on their design.
Remove the gasket from the end of the axle box
Products with a rubber gasket are more maintainable:
Use a screwdriver to unscrew the screw securing the gasket at the end.
We dismantle the sealing element and install a new one of the appropriate size in its place.
We fix the gasket with a screw, clamping it tightly enough, but without deformation.
It will be somewhat more difficult with ceramic axle boxes:
Remove the rubber gasket from the end, and then remove the end cap.
We dismantle the ceramic plates, if necessary, unscrewing their fixing element.
We clean the inner cavity of the axle box, removing dirt that can lead to leaks.
Fully disassembled ceramic axle box
We return the plates to their place, observing the correct position: when the stem is turned, they must completely cover the hole, interrupting the water flow.
We complete the assembly by replacing the dismantled elements.
Note! Leakage is often caused by wear on the ceramic plates themselves, so a complete replacement may be necessary. And it is quite difficult to find these parts, and the price of the repair kit will not be much less than the cost of a new axle box.
The device of the water tap and mixer, which is controlled by one lever, differs from the axle-box structure.
Accordingly, the dismantling of such a product for repair must be performed according to a different scheme:
First, lift up the red and blue front bezel.
Under the cover there is usually a screw for a Phillips screwdriver or a hexagon - we unscrew it.
Next, remove the handle, carefully disconnecting it from the stem of the ball or cartridge locking mechanism.
The next step is to provide access to the reinforcement itself. To do this, unscrew one or two nuts.
Note! Very often, manufacturers make an internal locking nut with grooves for a special tool. You can either purchase a similar wrench, or try to unscrew the part with your own hands using the tools at hand.
By removing the nut, we gain access to either the cartridge or the ball valve. They are dismantled quite simply, and the replacement will not cause difficulties.
Repair set for ball mixer
To restore the functionality of a single-lever mixer, most often it is necessary to completely change the functional element.
The instruction recommends to proceed as follows:
We remove the cartridge from the slot by pulling it vertically upwards along the guides. If the part is skewed, you can correct its position with a slight side impact.
We clean the cavity under the cartridge from rust and debris that can cause a leakage.
We install a new cartridge, fix it with one nut and check how well it blocks the water. If there are no leaks, and the adjustment is working properly, we assemble the mixer.
Cartridge removed from slot
Ball valves have their own characteristics. Their main advantage is that the ball itself rarely breaks, so repairs usually involve replacing gaskets. We act like this:
Grasping the stem, remove the ball from the socket.
Using tweezers or small pliers, remove the spring-loaded gaskets that press the ball against the body.
Removing the sealing elements
We replace the gaskets, after which we install the ball in place.
Put a new sealing ring on top and clamp the valve with a union nut for the mixer.
As in previous cases, it is better to check the tightness of the structure before complete assembly.
In addition to the actual repair of the locking mechanism, other measures are sometimes necessary to restore the working capacity of the crane.
For example, in case of problems with the aerator, we proceed as follows:
Using an adjustable wrench with plastic covers, carefully grab the aerator and unscrew it from the spout.
We take out the installed mesh and thoroughly rinse it, removing all dirt.
At the same time, we clean the mixer spout with a flexible brush, trying to remove layers from the inner walls as much as possible.
We screw the aerator onto the spout, making sure that the thread is not skewed.
If a leak occurs at the place of fixation of the swivel spout, we proceed as follows:
Gently twist the union nut using an adjustable wrench. We remove the "gander".
We remove the rubber gasket from the socket.
We install a new one in its place. The diameter and thickness of both elements must match.
We return the spout to its place, fixing it with a union nut.
It is this gasket that requires replacement.
Some malfunctions do not affect the operation of the mixer, but significantly degrade its appearance. Typically, these include scratches, chips, scuffs, etc. And although the full restoration of chrome or nickel plating is quite expensive, throwing away the tap and buying a new one is not at all necessary.
You can return an attractive look to the product by painting:
We dismantle the mixer, completely disassembling it and removing all non-metallic parts.
We grind metal surfaces, removing scratches, and then thoroughly degrease.
Metallic silver aerosol
Note! If the scratches are minor, then this polish can be applied without painting: it restores factory chrome / nickel plating well.