Water check valve for pump: types, principle of operation, installation

Boilers ensure independence from public utilities, supplying people with water around the clock and at any time of the year. If the safety valve is dripping in the water heater, this circumstance should be considered objectively, without nerves or showing emotions. First of all, you need to understand that the faucet is designed for water to drip from it. The only question is how often this happens and what volumes of liquid leave the tank per unit of time. A calm analysis of this phenomenon will allow you to understand the nature of its origin and take effective measures to eliminate the malfunction.

Main functions of a safety valve

The safety valve protects the device from excess pressure and water hammer.
The first water heaters went on sale without components; the packaging of modern products always contains a safety valve. The instructions for installing and operating the tank state that operating the boiler without this part is strictly prohibited. The manufacturer indicates the location and method of attaching the valve. This recommendation is justified by the fact that tanks have a limited safety margin, and excessive internal pressure can simply rupture them. This situation is extremely dangerous for the life and health of people and can cause large-scale flooding of several apartments in a multi-story building.

Main functions of a check valve:

• Discharge of water from the tank when, when heated, it expands and begins to press on its walls with a force greater than that provided by the calculated data. Depending on the pressure level, water may run or drip at different rates.
• Compensation for water hammer. During such phenomena, the water pressure increases to values ​​that are critical for domestic boilers. Thanks to a well-designed emergency mechanism, the faucet reduces the pressure by releasing liquid through a special pipe.

Most often, water drips from the boiler through the valve at night, when the volume of its consumption decreases significantly, but the pressure remains the same. The sound of falling drops may annoy household members, but this is not the worst thing. The main thing is that the emergency valves are working properly and people are not in danger. You can easily get rid of the noise - just tie a bandage, rope or long piece of fabric to the pipe and take it out into the bathtub, sink or toilet. Subsequently, the material should be replaced with an elastic drainage tube.

Principle of operation

If there is excess pressure, water is discharged into the sewer through the supplied pipe.
The check valve is a direct-acting safety pipeline fitting designed to protect water heating equipment from mechanical destruction under the influence of critical pressure. The principle of operation is to automatically adjust the water pressure inside the boiler. When it reaches the limit values, water is discharged. Release is carried out until the pressure reaches operating values.

The accuracy and functionality of the safety valve is determined by the parameters and settings of the internal parts.

Is it dripping or flowing?

If water drips from the check valve device during the heating of the boiler equipment, then this situation indicates the normal functioning of the device and the operation of the protective group in normal mode.

During operation of a water heating device, the safety valve must discharge excess liquid if there is an increase in water pressure on the walls of the storage tank as a result of thermal expansion of the liquid. The consequence of water discharge is a noticeable decrease in water pressure inside the tank with heating elements.

Installation diagram of a safety valve for a boiler

To monitor the process of removing excess water, it is necessary to install a regular transparent reinforced plastic pipe on the outlet fitting, the outlet of which is mounted on the sewer system.

The water should not flow in a stream, and the release of droplets should stop immediately after cooling.

If water drips constantly, the problem may be a malfunction of the safety valve device or the liquid is drained due to a worn rubber or silicone seal..

Types and design of valves

According to their design, products are divided into monolithic and collapsible. The first are a monoblock, inside of which parts are pressed. The second option is equipped with a hole through which, after unscrewing the lid, access to the inside of the product is possible. The valves also differ in the way they drain drainage. Some have drops falling from a protruding pipe, others are equipped with a closed piping system with outlet to the sewer.

Structure of safety valves

General arrangement of safety valves:

• Frame. It has internal and external fastening threads and a side pipe. Made from steel or brass. Can be plated with nickel, chromium or zinc.
• Big cylinder. Located at the bottom of the body. Opens when opening the mixer and to fill the tank. It closes after the pressure inside the container and in the water supply system is equalized. Prevents water from flowing back into the supply pipe.
• Small cylinder. Located in the middle of the product, it is equipped with a more powerful spring. It contracts when the water pressure in the boiler or water supply exceeds the established norm. The drainage hole is released, through which the liquid flows out.

High-quality products from leading manufacturers have clear markings made using the molding method during the casting process. There are no visible seams or other defects. Branded parts are accompanied by a certificate of conformity. The price of such a product can reach up to 1000 rubles, but the safety is worth it.

Where are they installed?

Installation of a check valve on water is carried out in the following places:

• At the outlet of a submersible pump lowered into a well or well. When the pump is turned off, the water will not return in the opposite direction;

  Installing a check valve on a submersible pump

• At the end of the suction pipe of a surface pump or pumping station lowered into the water. After turning off the pumping unit, water will always remain in the pipe;

  Check valve for a water supply system based on a pumping station

• At the inlet of the cold pipeline into the boiler. In this case, if there is no water in the pipeline, the liquid will not flow back from the boiler;
• For various types of water supply systems, especially if cold and hot pipelines are used simultaneously. The water pressure in the pipelines is different, so hot water may be forced into the cold line or vice versa through the mixer. A water back pressure valve installed in each individual line will prevent reverse flow;
• In autonomous heating systems, when there are several separate circuits with different coolant pressures. In this case, each circuit has a separate pump. If the power of the pumps is different, then a more powerful unit can push the coolant into the adjacent circuit, where the pump has less power. This absolutely cannot be allowed, so a water return valve is a mandatory element in such a system;
• On water meters to prevent water movement in the opposite direction;
• In sewer systems to prevent sewage backflow.

It is quite easy to install a check valve on water correctly with your own hands, because to do this it is enough to have minimal plumbing skills and also have the necessary tools. The basic rule during the installation process is to screw the valve in the desired direction . There is an arrow on the body of the device showing the direction of water movement through the valve.

We looked at why a check valve for water is needed, and also looked at the types and features of such valves. The use of these useful products can prevent emergencies in plumbing and heating systems, as well as significantly facilitate work with water pumps and pumping stations.

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Valve installation and adjustment

The safety valve is mounted on the cold water pipe.
The check valve is attached to the cold water pipe. For ease of work, manufacturers mark it in blue. You can screw the tap on at any stage of installation, but it is more advisable to do this before hanging the tank on the hooks. When the heater is on the floor, working with it is much easier, more convenient and safer.

Installation should be done in the following sequence:

1. Unscrew the mounting bolts and remove the plastic cover. To prevent it from interfering with your work, you do not need to remove the light bulb from it and then put it in a safe place.
2. Inspect the threads on the inlet pipe of the tank, visually check its integrity. Clean the coils with a brush and remove transport grease with a dry cloth.
3. Carry out a similar procedure with the upper union nut of the valve. If there are burrs, they must be carefully removed with a knife or file.
4. Wrap tape around the FUM pipe. This should be done clockwise, moving the thickening towards the side. The layer thickness should be 1 mm at the cut and 3 mm at the beginning of the thread.
5. Take the valve, catch the edge of the thread and start screwing it on. The product should go tightly and with effort. It is important that at the end of the rotation the nut does not rest against the side. This will mean that not enough FUM tape has been wound. The procedure will have to be repeated.

After fixing the safety valve, you can immediately attach the ball valve to it. The procedure is similar.

Causes of safety valve failure

With constant high pressure, the spring inside weakens, the part needs to be replaced.
If the valve on the boiler drips constantly, regardless of the time of day and the intensity of water use in the house, there is a high probability that the product is faulty. There can be many reasons for this.

• Manufacturing defects. As a rule, these are weak springs and leaky cylinders. Such products will operate even under operating pressure. Those who are trying to save money and buy cheap Chinese counterfeits have to deal with such a nuisance.
• Blockage. Occurs when the tank is not cleaned properly or due to poor water quality. The essence of the breakdown is that after compression, the spring cannot expand, since solid particles form an obstacle in its path. With such a malfunction, the product will leak even when the device is turned off and the tap is closed.
• High system pressure. This is not uncommon on the top floors of high-rise buildings with overhead water supply. Since the pressure is maintained at a constantly high level, the valve will leak continuously, regardless of the time of day.
• Mechanical damage. Occurs during transportation or during installation. Internal parts can also be damaged during cleaning - deformation of the spring, rupture of gaskets. When dropped, a gap appears at the point where the pipe enters the boiler body.
• Storage tank leaking. In such cases, there is water on the outside of the product, but it may appear that the valve on the water heater is leaking. The cause of leakage is corrosion or a broken seam.
• The top part is leaking. There is a weak connection. This is one of the most common causes of dripping on the valve. In most cases, this occurs due to a hardened gasket under the nut or insufficient amount of FUM tape.
• Wear of springs. Over time, they lose their elasticity and begin to shrink even with slight pressure. Nothing will help here. All that remains is to install a temporary drain and go to the store for a new valve.

Once a leak has formed, it will not go away on its own. The situation will only get worse until it reaches a critical state. Therefore, if the safety valve on the boiler is leaking, it is necessary to take urgent measures to determine the causes of this phenomenon and restore the functionality of the water heater.

Repair work

To diagnose and fix the breakdown, you will need to stock up on a set of tools and some consumables.

To work you will need:

• adjustable wrench, plumbing pliers, screwdriver;
• scissors;
• awl;
• indicator;
• FUM tape or tow;
• flexible hoses for easy draining of water from the tank;
• lemon acid;
• box for collecting small parts;
• rags.

Measures should be taken to protect limbs and vision. It is better to carry out repairs wearing protective glasses and gloves.

Valve repair is usually combined with scheduled boiler cleaning, so as not to waste time disassembling the device

First you need to make sure that the cause of the leak is the check valve. It is enough to check whether its body is dry or not. If there is no moisture on it, then you need to start disassembling. This event can be timed to coincide with cleaning the heater and the tank from scale. In any case, the effort will not be wasted.

Dismantling should be carried out in the following sequence:

1. Turn off the water. If a walk-through tap is installed in front of the mixer, it is better to turn it so as not to turn off the entire apartment.
2. Disconnect the device from electricity. Remove the cover and disconnect the wires from the terminals.
3. Unscrew the underwater pipes from the boiler. Remove the ball valve and safety valve.
4. Screw flexible hoses to the nozzles, the water will flow in the desired direction.
5. If there is a pressure gauge, check the operating water pressure. Ideally, it should be 1.5-2 atm.
6. While the liquid is draining, remove any remaining FUM tape and inspect the parts for cracks and dents.
7. Clean the tank and heating element from limescale and scale. Rinse the inside of the container using a shower head.

The removed check valve must first be washed under running water to remove scaly fragments. After this, the product should be immersed in a container with a solution prepared from water and citric acid in a ratio of 10:1. You can speed up the cleaning process by boiling. 10-15 minutes are enough for the valve to become like new. All that remains is to treat it with silicone grease and you can put it back.

Rating of the best check valves

Compiled based on the popularity of products in the Yandex.Market Internet service, as well as according to the opinion of shut-off valve buyers in online stores. At the same time, industrial units at inflated prices were not considered due to the lack of interest in purchasing them in everyday conditions, as well as during the construction of country houses. This review helps to better navigate the market for check valves needed for repairs. The rating is subjective and is not a guide to purchase.

TOP 3 butterfly type check valves

Tecofi CB 3448 DN100 RU16

3rd place.

Product with heat-resistant seal. Used for vertical or horizontal installation. The double-leaf mechanism is used in water supply, fire extinguishing, heating systems, as well as process pipelines.

When installed vertically, the opening of the valves must correspond to the flow. When mounted horizontally, the axis of the device must be vertical.

Characteristics:

Price: from 6200 rubles.

check valve Tecofi CB 3448 DN100 RU16

Advantages:

• low pressure loss;
• versatility;
• quiet operation;
• stainless steel springs.

Flaws:

• no clearly visible ones were found.

GENEBRE 2401 PN16 DN65

2nd place.

Direct acting wafer type device. It is used for water supply with hot and cold water, in sewerage, drainage, air conditioning systems, engineering pipeline systems, industrial systems of various types.

Characteristics:

Price: from 2300 rubles.

check valve GENEBRE 2401 PN16 DN65

Advantages:

• can be installed vertically, horizontally or at an angle;
• stainless steel disc;
• epoxy surface coating.

Flaws:

• no obvious ones were found.

Khlop CV-02/W DN 50 – 300

1 place.

The branded non-return valve is usually used for heating water supply, as well as in automatic fire extinguishing systems.

The popularity of the models determines their industrial use in the petrochemical, pulp and paper, metallurgical, cement industries, as well as water utilities. The collection of the model line contains nine items.

Characteristics:

Price: from 2700 rubles.

check valve Khlop CV-02/W DN 50 – 300

Advantages:

• can be installed horizontally or vertically;
• doors made of malleable cast iron;
• epoxy coating.

Flaws:

• cannot be installed vertically with downward flow.

TOP 3 disc type check valves

UNIPUMP 77027

3rd place.

Used to protect water supply and pumping equipment. A single-leaf mechanism is installed at the beginning of the suction line. Prevents incoming water from flowing into the water supply. The product is made of anti-corrosion brass, plastic membranes.

Characteristics:

Average price: 455 rubles.

check valve UNIPUMP 77027

Advantages:

• compactness;
• long service life;
• good anti-corrosion properties;
• light weight;
• excellent price-quality ratio.

Flaws:

• no obvious ones were found.

Quattro Elementi 771-800

2nd place.

An Italian-made product with a filter is used with pumping stations or pumps to prevent unintentional drainage of water from the system, including when the pump suddenly stops. The valve has an internal thread and a non-removable mesh. Made of brass, without springs.

Characteristics:

Price: 299 – 362 rubles.

check valve Quattro Elementi 771-800

Advantages:

• cast brass body;
• compactness;
• long service life.

Flaws:

• no clearly visible ones were found.

Kalde 20

1 place.

It is used for installation on cold and hot water supply pipes, as well as heating systems. Well suited for placement together with a water meter. Any installation position. New products work in any conditions at any temperature. Connection to the pipe is made by heat treatment, which requires a soldering iron. You can always order online.

Characteristics:

Price: from 230 rubles.

check valve Kalde 20

Advantages:

• corrosion resistance;
• low weight;
• good resistance to active substances in water;
• long service life;
• convenient installation;
• compactness;
• ease of transportation;
• positive user reviews;
• excellent price-quality ratio.

Flaws:

• no obvious ones were found.

TOP 3 swing type check valves

1″ BUGATTI 180

3rd place.

Horizontal product with a rotating brass core to prevent water flow in the opposite direction. Installed on pipeline networks for flow of cold or hot water, as well as compressed air, in only one direction. The direction of flow is indicated on the device.

Characteristics:

Price: 1500 rubles.

check valve 1″ BUGATTI 180

Advantages:

• low pressure loss;
• brass body;
• convenient installation;
• long service life;
• easy transportation.

Flaws:

• no clearly visible ones were found.

110 mm Aquaviva

2nd place.

A device with a coupling end to prevent the reverse flow of the medium in the pipeline. Made from high quality plastic that is resistant to oxidation or aggressive chemical elements.

Characteristics:

Price: 6900 rubles.

check valve 110 mm Aquaviva

Advantages:

• light weight;
• corrosion resistance;
• small pressure losses;
• compactness;
• good resistance to active substances in water;
• long service life.

Flaws:

• no obvious ones were found.

Tim JH-1014

1 place.

A product with a metal rod is used for heating systems, water supply, and the supply of various gases. Can be installed in any position.

Characteristics:

Cost: 720 – 1010 rubles.

check valve Tim JH-1014

Advantages:

• installation versatility;
• no rubbing surfaces;
• resistance to high ambient temperatures;
• high throughput.

Flaws:

• no clearly visible ones were found.

TOP 3 lift type check valves

Zetkama V277

3rd place.

A cast iron product is used to prevent backflow. The use of a spring that presses the lock ensures high tightness and stable operation on vertical or horizontal pipelines.

Characteristic:

Price: from 1740 rubles.

check valve Zetkama V277

Advantages:

• high tightness of closure;
• quiet operation;
• environmental Safety;
• no additional maintenance required;
• good maintainability;
• long service life;
• structural strength.

Flaws:

• no obvious ones were found.

Rushwork 487-025-16

2nd place.

A lifting-type device made of cast iron for automatically closing the reverse movement of the working medium. It is used in water supply networks, heating, air conditioning and refrigeration systems, as well as chemical, oil and gas, pulp and paper, and other industries. The arrow corresponds to the direction of the medium flow.

The body and cover are made of alloy cast iron with the addition of lamellar graphite. Alloy steel disc with low carbon content and additives of chromium, nickel, molybdenum is highly resistant to precipitation, acids or sea water. At high temperatures the properties do not change.

Characteristic:

Priced from 1980 rubles.

check valve Rushwork 487-025-16

Advantages:

• high resistance to external influences;
• reliability;
• long service life;
• graphite gasket for nitrile seal;
• good tightness.

Flaws:

• no clearly noticeable ones were identified.

Granlock RD16F

1 place.

The Russian-made product prevents backflow in the pipeline. The intended use of the spring element makes it possible to achieve high tightness of the lock and stable operation on vertical or horizontal pipes.

Characteristics:

Price: from 2000 rubles.

check valve Granlock RD16F

Advantages:

• high closing speed;
• reliable tightness;
• installation versatility;
• long service life.

Flaws:

• no obvious ones were found.

TOP 3 ball type check valves

Pedrollo VR-FT 2

3rd place.

Ball device with threaded connection, designed specifically for submersible pumps. Designed for vertical installation, backflow prevention, and protection of plumbing and pumping equipment.

Characteristics:

Price: from 7840 rubles.

check valve Pedrollo VR-FT 2

Advantages:

• special development for submersible pump;
• good tightness;
• quick installation;
• not subject to oxidation and corrosion.

Flaws:

• no obvious ones were found.

WATERSTRY

2nd place.

Cast iron ball product for drainage and sewerage. Passes water of any degree of contamination.

Characteristics:

Price: from 3600 rubles.

check valve WATERSTRY

Advantages:

• free passage increased;
• does not become dirty or jam;
• ease of cleaning through the inspection hole;
• durability of the material;
• lack of internal mechanisms.

Flaws:

• no obvious ones were identified.

1″ ALTSTREAM

1 place.

It is used when installing utility or drinking water supply systems, hot water supply, heating, compressed air, liquid hydrocarbons and process pipelines.

Characteristics:

Price: 416 rubles.

check valve 1″ ALTSTREAM

Advantages:

• high reliability;
• durability;

High quality nickel plated brass.

Flaws:

• no obvious ones were identified.

Extending the service life of the boiler

The main enemies of the boiler and check valve are impurities in the water and increased pressure in the pipeline. These problems are solved by installing an input main magnesium filter and a special gearbox. If this cannot be done, depending on the degree of water hardness, you need to carry out preventive cleaning of the boiler and its servicing fittings every 3-9 months.

In order to prevent strong expansion of the water in the tank, it is recommended to heat it to a temperature no higher than + 55ºС.

Design Features

The design of any check valve is not replete with complex parts. Regardless of the type of device, it consists of three required elements:

• Plastic or metal shutter with a silicone or rubber seal.
• A spring that ensures the shutter moves. Despite its small size, it performs a very important function, therefore, as a rule, it is made from high-quality steel.
• Device body.

To avoid the negative effects of aggressive chemical media (mineral salts, sulfur compounds, manganese, iron, etc.), dissolved in varying concentrations in any aquatic environment, the surface of the valve is subjected to additional protection. The protective layer is applied to the part using the galvanic method.

Some valve models can be equipped with additional elements to simplify the installation of the water supply network: a Mayevsky tap to allow air to bleed from the system, as well as a drainage hole to easily drain liquid accumulated in the pipe.

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