How to Set Up a Lawn Mower Valve

Water check valves belong to shutoff valves, and are designed to allow the flow of water in only one direction. This property allows them to be widely used, in particular, for self-priming pumps, as well as for creating autonomous water supply systems. So, the check valve for water for the pump prevents the return of the water raised by the pump back to the well or to the well. Another convenience of using such a valve is that you do not need to wait until the liquid displaces the air in the hose. If the hose has already been filled with water, the flow will begin immediately.

What elements does the check valve for water consist of?

The check valve device for water is quite simple. It consists of the following elements:

• Collapsible metal case, consisting of two parts, each of which is threaded;
• Plastic or metal shutter with gasket;
• Spring used to support the shutter.

How the check valve works

There is nothing complicated in valve operation. The check valve for water for the pump operates as follows. When water does not enter the hose or pipe through the pump, the valve is pressed by a spring and is in the closed position. When a sufficient water pressure appears in front of the valve to force the spring out, the valve opens, allowing water to flow into the pipe. When the pump shuts off and the water pressure drops, the spring again compresses the shutter, which closes. In addition to the spring, the water in the pipeline also presses on the shutter, preventing it from opening.

The most popular type of non-return valve for domestic use

Types of Check Valves

The non-return valve for water can vary in design, material of manufacture, installation features and dimensions. Let’s try to classify them according to these distinguishing features:

By type of locking element

• Lifting type. The shutter in such a device moves down and up. When water flows from the pump, the valve opens, and when the pressure drops in the line, the valve again switches to the closed position under the action of a spring;
• Rotary type. The shutter in such a valve has the form of a flap, which opens when the water moves, and closes under the action of a return spring when the pump is turned off. Pictured is a check valve for rotary type water
• Ball type. The shutter in the check valve is a ball that blocks the passage. The ball is supported by a spring. Water pressure raises the ball, which moves, and passes water into the channel;
• Wafer type. Subdivided into disc and bivalve. The disk check valve for water has a disk lock, which is able to move along its own axis under the action of a spring fixed to it. In a double-leaf backpressure valve, the shutter consists of two connected leaves, capable of folding when water passes, and if it is absent, to close. Butterfly Valve

According to the material of manufacture

• Brass. This is a reliable, corrosion-resistant material with durability and low maintenance. It is considered an ideal material for use in everyday life;
• Made of cast iron. This material is used relatively rarely, as it is susceptible to corrosion and gradual fouling by deposits. Cast iron valves are used on pipelines of large diameters. In everyday life, cast-iron valves are not used;
• Stainless steel. They are devoid of almost all the shortcomings. They are strong, resistant to corrosion and aggressive substances, durable. The price is the highest for a stainless check valve for water, but the quality of such a product is always at its best.

In most cases, the check valve components are made of different materials. So, the case can be brass or stainless, the shutter is usually plastic, and the spring may just be steel or stainless. Therefore, when buying, immediately be interested in what materials were used in the manufacture of the valve.

By way of fastening

• Coupling fasteners. In this way, the vast majority of check valves are attached. For fastening, 2 threaded transitions are used. Their diameter can be completely different, depending on the diameter of the pipeline;
• Flange mounts. They are attached to pipelines by means of flanges. These are mainly cast-iron valves used on pipelines of very large diameters;
• Wafer mounts. Valves are mounted between two flanges that are bolted together. Their use is also limited to pipes of solid diameter.

To size

• Standard valves. Used on most pipelines;
• Miniature products inserted into the overhangs of water meters. They are used if there is no place on the pipeline for installing a standard non-return valve;
• Small valves installed at the outputs of the meters;
• Large cast-iron valves installed on pipelines for public use and industrial purposes.

Various ways of connecting plastic pipes depending on the material are described in another article on the site.

And about the construction of a well house, read here.

Where are installed

Installation of a non-return valve on water is carried out in the following places:

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

Install a check valve on the submersible pump At the end of the suction nozzle of the surface pump or pump station immersed in water. After turning off the pump unit, water will always remain in the nozzle;

Check valve for water supply system at the base of the pumping station

At the entrance of a cold pipeline to the boiler. In this case, if there is no water in the pipeline, the liquid will not begin to drain back from the boiler;

For various types of water pipes, especially if both cold and hot pipelines are used. The water pressure in the pipelines is different, so hot water can be forced into the cold line or vice versa through a mixer. A water back pressure valve installed in each individual line will not allow its reverse current;

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 cannot be allowed at all, therefore, a water return valve is an indispensable element in such a system;

On water meters to prevent the movement of water in the opposite direction;

In sewer systems to prevent backflow of drains.

Video: How to Set Up a Lawn Mower Valve

It is quite easy to install the check valve on the water with your own hands correctly, because for this it is enough to have minimal plumbing skills, as well as have the necessary tool. The basic rule during installation is screw the valve in the desired direction. An arrow is marked on the body of the device, showing the direction of water movement through the valve.

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

Sometimes unpleasant circumstances arise when the heating system fails and the pressure starts to fluctuate. If pressure is not regulated, the consequences can be dangerous. In order to prevent this, the heating system and the hot water supply system should be equipped with safety valves. What is it and how they work – we will tell in this material.

Types of safety valves

Safety valve in the heating system performs a protective function in order to prevent high pressure. This is especially important for steam boilers.

Pressure rises most often due to such reasons:

• Failure of automatic pressure control systems;
• A sharp increase in ambient temperature and the appearance of steam.

Safety products are mainly of two types:

• Spring;
• Lever-freight.

In the lever-cargo structures, the load counteracts the pressure on the spool, its force is transmitted through the lever to the rod. It moves along the length of the lever, and in this way you can adjust the pressure force of the spool to the seat. Then it opens when the working medium begins to put pressure on the lower part of the spool with a force greater than the force of the lever pressure and the water leaves through the pipe.

And the spring safety assemblies work by electromagnetic drive. A spring exerts pressure on the spool rod, and adjustment occurs by changing the compression ratio of the spring.

Small heating systems are best combined with spring products, their advantages in this case are:

• Compactness;
• The setting can change only when using tools;
• The valve stem may have a different position;
• The possibility of combination with other products.

According to the principle of operation, safety valves are divided into the following:

• Direct acting devices;
• Indirect;
• On-off.

The direct-acting relief valve can only open under the pressure of the working medium, and indirect – under the influence of a pressure source.

And by the type of constipation lifting device are:

• Low lifting;
• Medium lifting;
• Full lift.

Materials of manufacture

Safety products can be made of such materials:

• Brass;
• Steel;
• Galvanized steel;
• Stainless steel.

Features of the mechanism and design

The safety brass coupling valve for the boiler is equipped with threads on both sides, there is a gasket on the input side. The mechanism is spring-loaded. External pressure can increase blockage. After assembling the structure, it is pressed, so the valve of this type is very reliable and affordable.

Safety valve also can work in sewer system in order to protect against back pressure.

Features of three-way valves

The purpose and principle of operation of the three-way safety valves is slightly different from other options and here their key differences:

• Application is permissible in low-temperature heating systems for cooling the carrier;
• It is possible to adjust the product manually or using an electric drive;
• The presence of one inlet and two outlet openings;
• To regulate the flow, there is a special valve in the form of a ball or rod, which directs it to the desired hole.

Such valves are most often used in heating systems, which include "heated floors". In this way, the water for heating the floors will be much cooler than the water in the radiator.

For the manufacture of three-way safety valves, apply:

• Steel;
• Brass;
• Cast iron.

Brass construction most common when installing home heating systems, and steel and cast iron are more characteristic of larger industrial installations.

It is also worth paying attention to an explosive safety valve, which is able to prevent the explosion of combustible gases or coal dust. They are made in such a way that if the substance explodes, then only the membrane of the structure is damaged, and the pipeline remains unharmed.

This type of product works in automatic mode. Depending on the pressure, their distinguish several of their types:

• With pressure up to 2 kPa;
• Up to 40 kPa;
• 150 kPa inclusive.

How to choose a safety valve

When choosing a safety valve, you should consider a huge number of various factors. In particular, be sure to consider the operating pressure of the environment. If this pressure is above normal, then you need choose a product at 2 bar, which can withstand similar product operating conditions. In addition, you can choose the option with the ability to adjust the pressure so that you can configure the desired mode and find out the exact parameters, in particular, the nominal diameter.

There are a number of rules regarding the execution of calculations; you can also find special settlement programs on the Internet. You can do without calculations, and take a design with a diameter of at least the diameter of the outlet pipe of your boiler, but such a calculation will not be accurate and will not be able to guarantee a high level of safety and performance.

In general, in order to choose the right product, you should think over the following parameters:

• Determine the type of product;
• With a size so that the pressure in the system does not exceed the permissible limits;
• It is better to choose spring-type products for the home;
• Open devices are only suitable if water escapes into the atmosphere, and closed devices if it enters the discharge pipe;
• After calculations, you can determine whether a low-lift valve or a full-lift valve is suitable;
• Calculate your budget.

Safety valve prices vary depending on the material and other features. For example, an Italian-made membrane construction can purchase for about 4 cu., and brass – starting from $ 12 There are also some models of valves, the cost of which exceeds 100 cu

Features of installing a safety valve

When installing the valve, you must strictly follow all the rules that are listed in the normative documentation of the product. Also, the installation must be carried out taking into account power and working pressure.

But Key installation principles are:

• Carry out a preliminary calculation of structural elements;
• Install on the supply pipe next to the boiler;
• It is recommended to put a manometer next to the valve;
• When using a spring design, the spring axis should be vertical and placed above the body;
• The lever lever of the truck-type valve should stand horizontally above the valve;
• In a hot water system, the valve must be installed at the upper point of the water heater at its outlet;
• It is impossible to narrow the diameters if the dimensions of the valve and the diameter of the pipeline do not match and other reasons;
• The connecting pipe should not be too long;
• After connecting to the pipeline, the pipes must be brought to a safe place;
• Valve settings are made 20 percent more than the operating pressure of the heating system;
• Check must be performed by forced opening.

Also, one should not forget that it is necessary to regulate and check the pressure at least once a year before the heating season.

How to set up a safety valve

The valve must be adjusted at the installation site after completion of installation work and after the system is flushed. Set the setting pressure, check the pressure of the beginning of opening and closing of the product.

Settings must be set slightly higher than the maximum working pressure, which is permissible under normal operation of the structure. AND full opening pressure should not be higher than the minimum level of the weakest element of the system. Closing pressure must exceed the minimum permissible value.

The pressure in the spring structure must be adjusted by rotating a special screw, which compresses the spring, and the lever structure is adjusted by the desired mass of the load.

So, valve ready for operation, if he is able to ensure the tightness of the overlap, as well as the complete opening and closing of the shutter. In addition, the pressure may deviate within the permissible fluctuations, which are given in the technical passport of the product.