Design and principle of operation of a water valve

Classification of water valve

The type, dimensions and design of the valve depend on the installation location and the functions performed by the device.

Plumbing fittings have 3 classification characteristics:

• body design;
• type of locking unit;
• diagram of device installation in the system.

The water valve carries the same loads as the pipes. Therefore, its strength should not be lower than that of the entire system. The parameters for which the product is designed are indicated on the valve body.

The design of a water valve depends on the functions it performs. An angle needle valve, which has a small flow area, is used to connect instrumentation.

A household water tap is made of a special shape to provide convenient, adjustable water drainage, etc.

Special models

In addition to classic valve devices, more modern taps are now widely used:

1. With thermostatic operating principle;
2. Sensory.

In thermostatic devices, a thermostat is connected to the locking mechanism. It comes with valves (for domestic use) and without them (for use in public places). During installation, the desired water temperature is set, according to the instructions or your own preferences, and then it does not change as you use it. If necessary, you can change the settings.

Photo - model with thermostat

Touch models do not require touching handles or valves. They are equipped with an active infrared indicator that constantly monitors the area around the sink. If you bring your hands to it, the locking mechanism will unlock and water of a certain temperature will flow (again, due to the thermostat installed in the spout).

Video on the topic:

Types of locking elements

Today there are 2 main types of water taps and valves:

• ball;
• valve

Simplicity of design and ease of use have made this fittings in demand among consumers. It has an acceptable service life and is widely used as a shut-off valve not only in water supply systems, but also in gas networks.

The design of this device does not allow it to be used to regulate fluid flow. The main disadvantage of the ball valve is considered to be complete non-repairability.

Valve fittings are shut-off and control valves and are widely used to change fluid flow over a wide range. This type of valve is characterized by its large size and the presence of moving parts in the locking mechanism.

Due to their design features, valve fittings have a short service life, since sealing elements made of leather or rubber quickly fail. However, it is possible to replace them, which extends the operating time without compromising performance.

Depending on the method of fastening the valves, the corresponding fasteners are used. In domestic systems, a coupling connection (American) or squeegees are most often used, and in industry, on high-pressure pipelines that do not allow leakage of working media, the fittings are installed by welding.

Types of locking mechanism

According to the type of constipation, all water valves and taps are divided into several types:

• Valve;
• Ball;
• Cork.

Below we will take a closer look at the features of all types of these devices.

Valve valve device

Valve

Valve taps are the usual locking mechanisms. The principle of their operation is based on blocking the passage with an elastic gasket mounted on the rod. The position of the rod is adjusted by a handwheel using a worm mechanism.

Thus, when the handle is rotated, the rod rises, resulting in the passage for water opening.

Among the advantages of this mechanism are:

• Ability to withstand high pressure;
• Ability to control flow;
• Ease of Management;
• Possibility of repair.

Along with the advantages, these products also have some disadvantages:

The gasket quickly fails because it comes into contact not only with water, but also with a metal surface. True, you can replace it yourself. As a rule, the device comes with an assembly drawing of the water valve, which shows how to disassemble the mechanism and replace damaged parts.

Removing the axle box gasket

• To completely open or block the passage, you need to make several turns of the flywheel yourself, which is not very convenient.
• The mechanism is less durable than other types of fittings.

For these reasons, recently such taps are installed quite rarely, only in cases where it is necessary to regulate the flow.

In the photo - a ball valve with a diameter of ¾

Ball

Ball water valves have recently become the most common. They received this name as a result of the fact that the locking mechanism is made in the form of a ball with a through hole. To block the flow, the ball is rotated with its hole perpendicular to the pipeline.

The plumbing ball valve has a number of advantages, such as:

• Durability due to the simplicity of the mechanism;
• Tightness when the passage is closed;
• To open the passage, you only need to turn the handle 90 degrees;
• Affordable price;
• Possibility of use in conjunction with servos and other devices that allow you to control the mechanism remotely or install it in automatic flow shut-off systems. (See also the article How to choose a mixer: features.)

Ball mechanism diagram

As for the shortcomings, there are few of them:

• The operating instructions for the device imply its use only to completely block or open a passage, i.e. it cannot be used to regulate flow. Otherwise, the mechanism will quickly depressurize.
• If the mechanism fails, it cannot be repaired.

Most often, this type of fittings is used in plumbing systems.

Plug tap

Cork

The design of a plug-type water valve resembles a valve valve, the only thing is that the flow is shut off using a conical plug, which is attached to the stem. When the rod is lowered, the plug enters the hole and tightly blocks the passage.

It should be noted that in recent years such fittings have been used extremely rarely in water supply systems, since more durable ball valves are installed instead.

Plastic ball valve 1 2 inches

Design and operating principle of a classic water valve

The valve (classic) valve consists of a cast two-chamber body and a movable locking mechanism with a drive. A straight-through (direct-flow) valve is installed on straight sections of pipelines to shut off or regulate the flow of liquid.

The design features of the angle valve allow it to be installed in places where pipes turn. The operating principle of these types of fittings is similar to each other, but the difference lies in the shape of the body.

In a straight-through valve, water is supplied to the lower, pressure cavity and through an opening enters the upper chamber, and then through a pipe to consumers.

The locking mechanism is a rod (spindle) with a thread and a valve plate with sealing material attached to it. When the flywheel rotates, the spindle moves the plate down toward the valve seat (orifice), thereby reducing its cross-section.

In this case, the liquid is throttled, and the pressure in the upper chamber decreases, which leads to a decrease in liquid flow.

The weak point of the design is the threaded block, because with excessive force when closing, the threads are torn off. This leads to failure of the entire unit. A gland seal is used to seal the rod.

To eliminate leaks along the spindle, tighten the union nut, which presses the packing to the rod through the bottom bushing.

Design and operating principle of a water ball valve

A valve with a spherical shut-off element has a simpler design. The body of the direct-flow design is most often made non-separable. The role of the locking mechanism is performed by a metal ball with a hole (valve).

Tightness is achieved due to the presence of gaskets installed between the spherical valve and the body. In most cases they are made of fluoroplastic or rubber. Some more expensive models use wear-resistant Teflon seals.

The ball is made of brass coated with chromium or nickel. This treatment of the locking part allows you to create a completely sealed structure. The valve is controlled by a manual drive made in the form of a rod welded to the ball.

In order to block the flow of liquid, the spherical valve is rotated 90°. There are stops on the body that prevent circular rotation of the ball. This is done in order to ensure optimal blocking of the fluid flow channel.

Sealing the place where the rod exits the body is achieved by installing gaskets that are pressed against a threaded bushing. The valve drive has downward petals that prevent the valve from turning more than a quarter of a circle.

Tap for water supply

Purpose

In arbitrary water supply networks - central, local or autonomous - shut-off and control equipment is used. The most common type of equipment is a water faucet.

The device is designed to regulate the throughput capacity and pressure functions of a pipeline by transforming the cross-sectional area of ​​the lumen of the pipe channel.

The products will be able to perform two main functions:

1. Locking function. The fittings have two positions - “open” and “closed”, and help to block or unlock the pipe channel. For the most part, shut-off valves have a small and ball-shaped handle rotation angle;
2. Adjustment function. Here, the closed and open positions are the extreme points, and the device allows you to smoothly change the cross-section of the lumen between these extreme positions. Such faucets are used on sinks and sinks, as well as in a channel version. They can have different designs.

Shut-off and shut-off and control valves are installed at the entrances of main pipes to the facility, in each individual room, at intersections and branches, before and after the end of metering equipment and plumbing fixtures, before and after the end of pumping equipment, at water intake points.

This widespread use is explained by the fact that plumbing equipment quite often breaks down and requires repair; in addition, preventive measures are often taken that require turning off the water supply. Using shut-off valves, it is possible to cut off a section of the network or a device from the system and replace it normally without draining the water.

varieties and device

Devices can be classified according to various parameters.

To begin with, let's divide them according to their intended purpose:

• Products for household needs. These are the familiar faucets on bathtubs and washbasins, kitchen appliances, etc.;
• For business needs. These are taps installed at the end of a pipe to connect irrigation hoses, water kits and other similar needs. They can be ball or valve;
• For the needs of the water supply system. These devices are built into the system and have a coupling design (much more often). With rare exceptions, these are ball valves.

For domestic needs, not simple designs are used, but mixing ones. They allow you to regulate not only the pressure, but also the temperature of the water by mixing warm and cold flows in various proportions.

The following possible solutions are possible:

1. Two-valve. The mixer has two separate valves for warm and cold water. Adjustment is made by both thumbwheels;
2. Single lever or surgical. The mixer has one handle that regulates the pressure and proportion of the mixture;
3. Automatic. The mixer is a three-way valve with a thermostat, and opening is carried out by a simple ceramic axle box or a servo drive at the command of a displacement sensor. Such designs are still distinguished by too high a price.

There are four types of designs: worm, ball, ceramic valve boxes and ceramic lever cartridges for the mixer.

The former are obsolete and are actually not used, since they are the least reliable and require frequent replacement of rubber gaskets.

Ball structures are easy to construct: a spherical plug with an axial slot is installed in the coupling body, which fits well to the saddle in which it is located. A spindle is attached to the ball. Using the spindle, we can turn the plug either with the slot facing the channel lumen, or with the side without the slot.

Ceramic locking mechanisms use the same principle, only it is not the ball that moves, but one plate relative to the other. Ceramic axle boxes, like cartridges, are distinguished by high reliability, smooth running, and quiet operation. But they are sensitive to water quality and require the installation of purification filters.

In most cases, household taps are simpler in design - they do not have a mixer and are a simple valve-type locking mechanism. Modern models are equipped with a ball mechanism or a ceramic valve axle box; worm-type valves are slowly being forced out of the market.

It must be stated that ball and valve mechanisms are used not only in water supply networks: they are installed on all types of pipes, so quite often the client is not able to understand how a gas tap differs from a water tap. Their designs are monotonous, only the materials and some nuances differ.

Which water valve to choose

The choice of shut-off valves is small. Ball valves are most often installed on domestic pipelines. Due to their simplicity of design, reasonable price and service life, they are in great demand among consumers.

When installing plumbing systems, only shut-off valves with a spherical valve are used to connect the flush cistern of a toilet, shower or washbasin. Its small dimensions allow it to be installed on installed pipelines.

Due to the prevalence of the product, the market is flooded with fakes. Often these are “one-time” valves, made of silumin or low-quality steel and have a low price.

In most cases, such products are destroyed during installation. When purchasing a ball valve, you must remember that a quality product does not come cheap.

To choose the right water valve, you need to pay attention to the following details:

1. Frame. Must be made of brass or bronze. The part is heavier than steel or silumin.
2. Valve. It has a shiny surface and is not magnetic.
3. Tightness. The valves are sold closed. When turning the handle, a characteristic pop should be heard.
4. Ease of valve movement. Should be easy to move. A slight force is generated when reaching the end positions.
5. Thread. The wall thickness is the same and is sufficient to ensure strength during installation.

The purchased high-quality device will not cause trouble during operation and will perform its functions for a long time.

Source: trubyda.ru/vodoprovodnye/ventily

Categories of pipeline fittings

Safety valve blocks2 Steel valves104 Cast iron valves47 Stainless steel valves16 Steel valves - HL3 Steel valves77 Cast iron valves37 Hose valves1 Sewer fittings6 Check valves82 Safety valves50 Control valves72 Steel condensate drains3 Bronze valves23 Steel valves - HL45 Cranes stainless31 Steel taps79 Bronze valves18 Titanium taps1 Cast iron taps2 Hardware3 Pumps2 Bends20 Heating equipment36 Switching devices1 Transitions18 Control valves31 Fire fittings44 Water meters31 Tees13 Pipes46 Level indicators3 Sealing materials18 Filters, mud traps54 Fittings26 Flanges32 Elevators7 Electric drives1 Ball valves81 Other27 Pneumatic actuators2 Cast iron condensate drains2 Steel valves38 Chu valves gunny31 Energy valves1 Energy gate valves3 Energy valves1 Shut-off valves12 Bellows compensators40

Types of water valves

The following types of water valves are available:

• valve;
• ball

The principle of operation of a valve valve is to shut off the water using a gasket mounted on the stem.

The main advantages of the valve valve are:

• the ability to control water flow;
• the ability to carry out repairs yourself.

The disadvantages of valve valves include:

• fragility of the device. The gasket, which acts as a lock, comes into contact not only with water, but also with the metal body of the valve, which leads to increased natural wear;
• difficulty using the device. To completely block the flow, it is necessary to make several revolutions with the control flywheel.

Ball valves shut off the water thanks to a shut-off mechanism made in the shape of a ball. When the control lever is turned, the hole in the ball turns over perpendicular to the fluid flow.

The advantages of ball valves include:

• simplicity of the device, which guarantees a long period of use;
• complete tightness in the closed position;
• ease of use. To completely shut off the water, you must turn the control knob 90º.

The disadvantages of ball valves are:

• impossibility of limiting the flow (exclusively complete overlap);
• impossibility of carrying out routine repairs. If the device no longer performs its functions, a complete replacement will be required.

To completely shut off the flow of water, it is more advisable to install ball valves. If you need to regulate the water flow, it is better to install a valve valve.

By design, the water valve can be:

• passable. A straight-through valve allows water to flow in a certain direction and serves to shut off the flow. Installed exclusively on a flat section of water supply;
• direct-flow. A type of straight-through valve with less hydraulic resistance;
• corner. The valve is installed on the corner pipe connection. The incoming flow is perpendicular to the outgoing flow.

Types of cranes

Ball

Ball valves have recently become very popular because they have an extremely simple design, which results in their long service life. In addition, they are easy to use, since to shut off the flow you only need to turn the handle 90 degrees.

The locking mechanism of this device is made in the form of a ball with a through hole. To block the passage, the ball should be turned with its hole perpendicular to the body.

The ball valve is controlled by a handle, which is connected to the ball via a rod. To seal the mechanism, two elastic rings are used that fit tightly to the ball.

The body of the ball device can be made of brass, aluminum or polypropylene. Plastic taps are installed together with plastic pipes for the heating system.

Pictured is an angle valve.

It should be noted that this fitting has the following disadvantages:

• Sensitivity to impurities in the coolant. Therefore, when using water, it is advisable to install filters.
• Not intended for smooth flow control. If it is used for these purposes, the mechanism will quickly fail.

Therefore, ball valves are often installed on the return line to completely shut off the coolant flow.

Valve device

Valve

A manual valve or manual radiator shut-off valve is a structure within which the direction of coolant flow changes twice. The closing element in such valves is a rod with an elastic gasket. The position of the rod is controlled by a worm gear with a handle.

When the gasket is pressed tightly against the seat, the coolant passage is closed. If you rotate the handle smoothly, the gasket will gradually open the passage. The advantage of this design is the ability not only to completely shut off the coolant flow, but also to regulate its intensity.

However, it should be borne in mind that the rubber gasket deteriorates quite quickly, as a result of which it does not seal the flow tightly. This problem can be solved by replacing the gasket, which is easy to do yourself.

Valve with thermostat for radiator

Shut-off valve with thermostat

A shut-off valve for a heating radiator with a thermostat allows you to regulate the intensity of the coolant flow automatically. This device is also called a thermal valve or thermal valve.

The shut-off valve design for this type of radiator is relatively simple.

Its locking mechanism consists of the following elements:

• Metal body with passage hole and seat.
• Elastic cone.

Valve device with thermostat

During operation of the device, the cone lowers and rises, as a result of which the amount of coolant passed through changes.

The position of the cone in the seat is controlled by a thermal head (thermoelement), which consists of the following elements:

• Cylinder (bellows).
• Thermal agent is a liquid or gas that fills the bellows. The thermal agent greatly changes its volume as a result of changes in ambient temperature.
• The piston is connected to a cylinder on one side and to a cone on the other.

Under the influence of temperature, the thermal agent contracts or increases in volume, which sets the piston in motion, which in turn changes the position of the cone through the rod. The thermal head allows you to regulate the temperature at which the valve completely shuts off the water.

It should be noted that there are two types of thermostats:

• Mechanical;
• Electronic.

Electronic model of thermal valve

The latter are usually equipped with a display and sensor that displays the air temperature. Such devices allow you to set the temperature conditions of the shut-off valve at different times of the day or even days of the week.

For example, from nine in the morning to five in the evening, when all household members leave, you can set the temperature to a lower value, and after five, the radiator will warm up to higher values ​​and better warm up the room. The price of such devices, of course, is quite high.

Heating battery wiring diagram

Selecting valve material

The water shut-off valve can be manufactured:

• made of brass. The material is characterized by its low weight, small overall dimensions and durability. The main disadvantage is the high cost. The brass valve can be installed for both cold and hot water;
• made of bronze. The cost of a bronze valve is higher than that of a brass valve, and the characteristics of the devices are almost identical;
• made of stainless steel. Relatively cheap devices are more susceptible to scale deposits. Therefore, they are practically not used for hot water;
• made of plastic. Plastic valves are also durable and low cost. Plastic is practically not subject to corrosion and scale deposits.

Brass or bronze valves, as well as stainless steel devices, are installed on metal pipelines. Plastic valves are installed exclusively on plastic water pipes.

Details

Water supply valves are selected taking into account the material of manufacture and the method of connection to the pipeline provided by the manufacturer.

Types of materials for devices

The characteristics of products made from different materials differ. For the production of water valves the following is used:

1. Steel. The parts are resistant to water hammer. Steel water supply valves used in domestic conditions have a valve or plug type design. Steel components are resistant to temperature changes and mechanical stress.
2. Brass. Units of this type are used in domestic and industrial environments. The housing is resistant to temperature changes and mechanical stress. Brass mechanisms are used for cold and hot water supply systems.
3. Stainless steel. Stainless steel housings are used in valves intended for installation in pipelines of various diameters. Stainless steel is resistant to corrosion, mechanical stress and the negative influence of aggressive substances.
4. Cast iron. Shut-off elements of this type can withstand high pressure in the line. The parts are heavy and low cost. The cast iron body does not withstand mechanical stress well. Impacts may damage the integrity of the surface.
5. Plastic. The material is durable and resistant to temperature changes. Plastic valves are used for hot and cold water supply. In this case, the body is made non-separable. To install the plastic assembly, use a specialized soldering iron.

Brass Ball Valve

The material of manufacture is taken into account when selecting a unit for systems with certain characteristics. This makes it possible to increase the service life of the locking elements.

Types of connections to the pipeline

Before replacing the valve on a water pipe, it is necessary to determine the type of connection. This way it will be possible to replace the unit without the use of additional connecting elements. Shut-off structures have the following types of connections to the pipeline:

1. Coupling. The water valve connections are equipped with internal threads. The assembly is screwed onto the pipeline. To prevent leakage, the threaded connection is additionally sealed with specialized tape.
2. Welded. The inlet and outlet of the shut-off element are made in the form of pipes. They are connected to the pipeline by welding. To replace this type of water valve, specialized equipment is used. After installation, a one-piece structure is obtained. For dismantling, the structure is cut out from the system.
3. Tsapkovoe. Sides are installed at the edges of the pipes. They engage with the nuts. A rubber cuff is installed between the pipe and the pipe. This makes it possible to achieve a tight connection.
4. Flanged. Flanges are installed on the pipes and valve body. They have holes for installing threaded fasteners. The number of holes depends on the size of the part. During installation, an elastic seal is placed between the flanges. Once the fasteners are tightened, the seal eliminates the possibility of leakage.

Tools are used for replacement. These are wrenches, gas wrenches or adjustable wrenches. Only components intended for welding are installed without the use of keys.

Flange valve

Connection method for plastic valve devices

The connections of plastic parts have a high degree of tightness. This is achieved through a special installation technology. Installation involves the use of specialized equipment (soldering iron).

The parts are heated to high temperatures. The surfaces to be joined are subjected to heating (internal on one part, external on the other).

After heating, the components are connected and held motionless until they cool.

Under the influence of high temperature, the surface of the plastic softens, the material of different components is mixed. This produces a monolithic joint without a seam. This ensures reliable sealing of the pipeline where the valve is fixed.

It is impossible to dismantle the plastic component without compromising the integrity of the line. To remove the mechanism, cut out part of the pipeline.

Selecting a valve mounting method

According to the method of fastening, water valves are divided into:

• threaded Installation is carried out using a thread and a locking locknut, which is located on the water pipe and the device itself. The threaded valve must be selected according to the type of thread (internal, external), its diameter and pitch. Installation is possible on both metal and plastic water pipes;
• flanged. They are fastened using special devices (flanges) located on the edges of the valve and water pipes, and connected to each other with fastening bolts. The devices are installed primarily on metal water supply systems;
• welded Mounted by welding. Weld-on valves can be installed on metal and plastic pipelines.

Threaded and flanged valves can be removed for repair and reinstalled. It will not be possible to install a welded valve a second time.

Installation of shut-off valves in the system

In a heated towel rail system, a shut-off fitting closes the radiator and at the same time the flow of warm air. The valve position is adjusted using a control handwheel or a small switch knob (in modern products).

When installing a valve, the material from which it is made and the design type (ball, valve) are taken into account. Installation can be threaded or flanged. The first type is performed when small diameter pipes need to be connected to the system - up to 6 cm, the second - for large-sized pipes (up to 160 cm).

To install a “Grohe” or “Hansgrohe” thermostatic locking mechanism on a heated towel rail, you must:

• Screw the valve into the coupling
• On the other side, attach a pipe to the coupling. This is achieved by screwing the threaded pipe fitting into the fitting seat.
• Seal the joints of individual elements with fluoroplastic film. If a brass corner valve is installed, the joints can be soldered by welding.

How to install a valve on a pipe

The installation method depends on the type of valve chosen.

Installation of a threaded valve

Installation of a threaded water supply valve is carried out according to the following scheme:

• If there are no threads on the pipes, then they can be cut using special equipment. To do this, use a die of the required size. Thread cutting is done by rotating the die along the pipe. For convenience, you can use a die holder;
• Lock nuts are put on the ends of the pipes to act as valve clamps;
• the thread is sealed. As a sealant, you can use FUM tape, linen thread, or a special Tangit Unilok thread;
• the valve is screwed onto the sealed thread and secured with locknuts.

Flange valve installation

You can install the valve on a water pipe using flanges according to the following scheme:

• flanges are attached to the ends of the pipes using arc welding;
• Rubber gaskets are installed between the flanges on the pipes and the flanges on the tap to ensure a tight connection;
• the flanges are bolted together.

After installing the valve in any way, it is recommended to check the tightness of the connections. To do this, water is supplied to the system gradually.

Thus, you can choose a valve for the water supply and install it, knowing simple instructions, on your own. This does not require special skills or a large set of tools.

Source: vse-o-trubah.ru/ventil-dlya-vody.html

Installation of flanged valve

The installation procedure for a flanged valve is considered quite simple, although it must be performed in a certain sequence:

• Steel flanges are mounted on both ends of the connected pipes by welding. Their dimensions must correspond to the dimensions of the flanges at the ends of the valve.
• The pipes are separated to a certain distance into which the mounted valve is placed.
• The holes on the flanges of the pipe and the valve are aligned, after which bolts are inserted into them. O-rings (polymer or rubber) are placed between the flanges of the valve and the pipe, after which nuts are screwed onto the bolts.
• The final stage is tightening the threaded connections. Tightening should be carried out correctly in this order: each bolt-nut pair is tightened 3-4 turns, after which we move on to the next one until all connection points are completely fixed.

Water valves: installation and repair

Water valves are a special design in water fittings. They are installed as a locking and regulating mechanism.

This valve stops the flow of water thanks to a special locking mechanism. It has a movable element, also called a spindle, screwed into the thread of the nut on the cover.

The locking mechanism can be mounted in any position due to the existing thread, while spontaneous movement of the mechanism under the influence of water pressure is simply impossible.

This feature is used not only to stop the pressure of the working medium, but also to control the pressure of the pressure.

Today, different types of water supply valves are used; they can be divided into a number of separate groups: through-flow, corner, direct-flow.

They are also divided according to the type of sealing - gland and bellows, and according to the type of thread - into water supply with external thread and submersible. A specially installed diaphragm, called a membrane, can also be used as a locking element.

All water valves differ in the following properties:

• conventional design - these devices require little maintenance and are easy to use;
• possibility of operation at high pressure drops;
• dimensions and weight are small, can be installed on any necessary section of the entire pipeline;
• small working stroke of the locking mechanism, this creates additional convenience during operation.

There are also shut-off and control water mechanisms with a profiled cork valve; they are called needle valves.

Options for wiring diagrams of a two-pipe system

Upper wiring

A system with overhead wiring is suitable when implementing natural circulation (without the use of pumps) (gravity heating system). It has lower hydrodynamic resistance. In this case, the upper supply main pipe is partially cooled. Due to this, additional coolant circulation pressure is generated.

Bottom wiring

In a system with bottom wiring, both the supply and discharge pipes are located nearby.

There are such modifications of the lower wiring:

• “star” (radial) - from the collector to the radiator there is its own supply and its own return pipe;
• “loop” - collectors bypass all radiators in series

The principle of difference between one-pipe and two-pipe wiring

So, is the heating system one-pipe or two-pipe? In each case, it is necessary to have preliminary calculations and a design (see Leningradka single-pipe heating system), on the basis of which both heating devices and the main pipes themselves will be selected (see reinforced polypropylene pipes for heating). The final decision is yours.

Water valve design

All valves are manufactured in two types: valve and ball. Valve devices are a design of the usual locking mechanism, which are located in every bathroom and are installed to shut off the water.

These mechanisms are quite convenient, they can even conduct water with a high content of chlorine, and their repair consists only of replacing the seals.

Ball mechanisms are more decorative; they have only one handle, which turns in different directions. Using this mechanism, you can adjust the pressure and temperature of the water.

These valves are made of brass, they are quite durable and lightweight, they are small in size, and therefore require almost no free space during installation.

Steel devices, unlike brass ones, differ in appearance; instead of a handle, they have a convenient wheel, by turning which you can adjust the pressure or stop the water pressure.

These mechanisms also differ from brass, cast iron and bronze in their nominal pressure and operating temperature range.

Steel valves are used in different conditions, they are quite durable, reliable and durable. They are made from stainless unalloyed or alloy steel and have a flanged design.

When installed in the pipeline, the inlet and outlet pipes are welded, this ensures a complete absence of leaks.

The peculiarity of steel valves is as follows:

• Possibility of operation in any position;
• simple design, which greatly facilitates repairs;
• ability to work at elevated temperatures and pressure.

A stainless steel water valve is installed on water supply systems that require anti-corrosion properties, as a rule, these are water supply systems in large industrial premises where the performance characteristics are very aggressive.

High pressure valves can be used to regulate and shut off water pressure; they are most often installed in boiler rooms in industry.

The diameter of the water pipelines on which these mechanisms are installed is usually 100–300 millimeters, the water temperature can be up to 4500 degrees, and the pressure can be up to 2.5 kilograms per 1 square cm.

This mechanism comes complete with a special seat, the locking element has a shank and a sleeve, the locking mechanism is directly mounted on a spindle, which can be rotated manually or using electric and hydraulic drives.

The device itself may be different:

• direct-flow if it is impossible to reduce the pressure;
• angular for fixing two perpendicular sections;
• passage for flat areas;
• mixing to obtain the required temperature, dilute the main medium, concentrate, maintain quality, and so on.

These water valves are light in weight and small in size, the seals can be installed in any position, they are easy to attach, and have excellent protection against leaks.

As a rule, cast iron valves are used for pipelines of private and apartment buildings, for country houses, garages, greenhouses and conservatories.

These devices, which have a fairly large mass, nevertheless have the following clear advantages:

• installation is extremely easy - you only need to have the simplest tools;
• they are quite reliable, withstand high water pressure, and are resistant to deformation;
• low cost;
• long service life, fairly simple maintenance, the likelihood of failure is minimized.

Specifications

Main technical characteristics of shut-off valves:

• Shut-off valve control: manual, gear, electric.
• Technical specifications according to GOST 3326, GOST 9697,
• Nominal diameter: DN 15-400 mm,
• Nominal pressure: from vacuum 5·10−3 mm Hg. Art. up to 250 MPa.
• Temperature: -200 to +600 °C

Material versions of steel:

• carbon,
• alloyed cold-resistant,
• heat-resistant stainless steel,
• stainless steel with special properties.

Water valve repair

Water valves are characterized by a very simple design, so breakdowns are quite rare. The biggest problem is thread breakage due to careless handling. Also, damage may result from difficulty turning the handle in the absence of regular cleaning, lubrication, and painting of the valve.

The worst damage is an adhesion to the pipeline, which will entail cutting or cutting off the valve directly with a piece of water supply, often accompanied by welding work.

In this case, you need to buy and install a new valve and re-thread the pipeline. But to prevent all this from happening to a water valve, the same preventive measures are necessary as for all other plumbing fittings.

In this case, breakdowns can be prevented in advance or completely minimized.

As a rule, repairing a valve for an untrained person causes certain difficulties, which are associated not with the laboriousness of the repair, but with ignorance of its design features and design.

The main thing is not to forget that it is very difficult to damage the valve with careless actions; it does not have ceramic, highly fragile chrome-plated mechanisms inside, that is, during repairs you don’t have to worry that careless movements will break parts of the mechanism.

But it is not advisable to disassemble the valve using ordinary pliers, because it is very easy to strip the thread in this way, which entails completely replacing the valve. If you don’t have a wrench or wrench, you shouldn’t start repairs (if disassembly is required).

Design features of the case

Valves, depending on the shape of the body and the method of installation on the pipeline, can be:

• direct-flow - in them the flow of transported liquid moves through the body from inlet to outlet without changing direction, the spindle axis is located at an angle to the axis of the passage hole. This design helps straighten the flow and reduce hydraulic resistance, but increases the working stroke of the valve, the parameters of the construction length and the weight of the product;
• pass-through - a product with the same direction of flow of moving water at the inlet and outlet and the axes of the inlet and outlet pipes shifted parallel to each other. Passing through the valve body, the water flow is forced to make at least two turns at right angles, which leads to the formation of high hydraulic resistance and the formation of stagnation zones;
• angular - in them the flow turns by 90º only once, therefore the level of hydraulic resistance is lower. Such products have restrictions on the area of ​​use - they are placed on the pipeline plan only on its rotating sections;
• mixing - in them the adjustment of the proportions of water occurs due to the mechanical rotation of the internal elements of the body. Designed to shut off and mix cold and hot water flows.

Removing blockages and painting

Often, a water valve needs painting, which is a great time to check and clean it. It is necessary to completely remove the old paint, inspect the surface of the mechanism, and prime the metal with drying oil.

We must not forget that complete removal of the valve will inevitably entail shutting off the water intake on the riser, so if it is possible to make repairs without turning it off, this should not be neglected.

It is often necessary to remove blockages that are preventing water from flowing with sufficient pressure. Serious blockages require complete removal of the valve, but small ones can be removed very simply, even without the use of special tools.

This can be done like this: you need to turn on all the taps in the house, including the tap on the cistern. Then open and close the water valve a couple of times. The pressure will rise significantly, and a small blockage will simply be washed away by the pressure of water on its own.

The water valve often needs replacing the seal and gaskets, which is very similar to the same repair of conventional faucets. To do this, you need to turn off the water in the riser, carefully disassemble the equipment and replace the gasket with a new one.

The gasket itself is very similar to the material for the tap, but it is stronger and denser, because it is under high loads.

We recommend installing fiber, paronite or heat-resistant rubber under the gasket, because elevated temperatures (for a pipeline with hot water) significantly deteriorate the properties of the rubber gasket.

Replacement may be necessary for both the stem and the spindle, also remember to lubricate the handle to turn off the water pressure, make sure that the valve fasteners are tight.

Where to install the check valve

First, a few words about how a water check valve is indicated on the diagrams.
There is a special icon for it. These are two triangles with their vertices facing each other. One of the triangles is shaded, one is not. The direction of movement of the working medium is indicated by an arrow. In the opposite direction the flow is closed. Graphic designation of a check valve in diagrams

In general, there is no clear indication of where exactly the check valve should be installed.

It is important that it performs its functions, and the location of its installation is a secondary matter. The water supply or heating system must work correctly

And you determine its specific location based on the system parameters and ease of maintenance. The exception is the water supply in the apartment. Here they will clearly tell you that we install the check valve in front of the meter and nothing else.

Where to put a check valve on the water when introducing it into the apartment - after the meter

For example, in the boiler piping there should be a non-return (shut-off) valve in the supply pipeline. It prevents hot water from entering the system, which can happen when the water heats up and this creates increased pressure that can “overwhelm” the water supply. In this case, it is better to place the return line closer to the source of hot water, so as not to subject other piping elements and cold water pipes, which today are not always made of metal, to thermal stress.

On a well or in a well with a submersible pump

If you are looking for information on where to install a check valve on a submersible pump, the information may be contradictory. Some advise installing it immediately at the outlet of the pump, others at the entrance to the house or in a pit if we are talking about a well. Oddly enough, all three options work. Just for different occasions.

We select the installation location of the check valve in the water supply system depending on the parameters of the system and equipment

It is possible to install a check valve in a house or in a pit above a well if the vertical section of the pipeline does not exceed 7 meters. The length of the horizontal section (if it is without slope) does not matter. With such a length of the pipeline, water will not flow back into the well or well.

Installation location of the check valve in a water supply system with a submersible pump

If the water surface is below seven meters (the pump draws water from a depth of more than 7 meters), we install a check valve after the pump. You can do it right away (as in the photo above), or you can install a filter, then a check valve. It is permissible to install the valve a couple of meters above the water level. This no longer plays a big role. But this installation method - at depth - is inconvenient for maintenance. Sooner or later the valve will have to be either cleaned or replaced. If it is in a well or in a well, everything must be taken to the surface. The replacement itself takes just a few minutes. It takes about five minutes to unscrew the thread, remove the old one, check/clean it or install a new one. But all the preparatory work is hard, wet and unpleasant. So, if possible, we move the check valve into the house or pit.

With pumping station

As already mentioned, some models of pumping stations have a check valve. Is it necessary to install a second one on the suction pipe? Again, if the water rises less than 7 meters, you can do without it or place it at the entrance to the house.

For a pumping station, a check valve with a filter is better

If the vertical rise is greater, it should be installed at the entrance. For what? Because when the pump is turned off, the water will flow back. And when turned on, it will pump air, and only then water. And let’s say right away that not all stations tolerate this regime well. Therefore, if you hear that water returns to the well or borehole after turning off the pump, it is better to redo the system.

Check valve with filter for installation with a pumping station

As you can see, in this scheme the check valve is installed at the end of the pipe. Since it is sensitive to contamination, it is better to pre-purify the water. You can screw on standard filters, or you can supply them with a built-in mesh. Which option is better? Probably, after all, the first. Firstly, you can assemble as many filters in series as necessary to supply relatively purified water. Secondly, it is cheaper to change one filter or one valve than a filter with a valve. There is more fuss during installation, but not critical.

Expert advice

• It should be borne in mind that you cannot put plastic on the input - if it fails, it will take a long time to change it. Cast iron and steel rust – these materials should be discarded.
• Do-it-yourself installation of any gas pipeline elements is prohibited - and it is better not to experiment for safety reasons.
• Copper fittings are used for copper water supply systems. Soldering copper pipes and fittings is difficult - best left to a specialist.
• You should not use tow during installation - modern FUM tape insulates the joints more reliably and allows you to easily unscrew the threaded connection in the event of a breakdown.
• If it is necessary to weld a metal-plastic pipe, it is necessary to remove the top two layers of polypropylene and aluminum foil (there is a special device for this - a shaver). You cannot weld plastic at subzero temperatures.
• If you are replacing a product on a threaded connection and it does not unscrew, you should use a special thread lubricant (for example, WD-40).
• When installing the tap, the direction of liquid flow must coincide with the arrow on the tap.