Check valves for sewerage (photo). How to install a check valve on the sewer?

From home. However, there are times when sewage flows back into the plumbing fixtures due to blockages. To avoid this phenomenon, a specially designed plumbing device is used - a check valve for sewage. Its task is to prevent the ingress of sewage back. The reason is the occurrence of blockages in the sewer system in various areas, when runoff water cannot move on and begins to accumulate. This subsequently leads to their return.

Where is a non-return valve installed in the sewer

A non-return ("fan") valve can be installed in a number of places in the sewer system, depending on the purpose. As a rule, two options are used:

• One valve that has increased capacity. Install it on a common sewer pipe.
• Specialized valves are installed on each plumbing item separately.

Types of blockages

To protect the room from the penetration of an unpleasant sewage mass, a check valve should be installed on the sewer.

Types of check valves

Check valves for sewerage are made from various raw materials: plastic, cast iron or steel.
Depending on the type of installation, it happens:

• horizontal;
• vertical check valve for sewerage.

In addition, they have differences in the operation of the limiter and their design.

When there is a pressure of sewage, the damper becomes in a horizontal position, without interfering with their subsequent movement, and after the pressure drops, it takes its original position. If there is a reverse flow of the waste mass, its cover rests against the restrictive walls of the pipe and does not allow them to move further. Strong pressure brings the opening angle of the lid to no more than 90 degrees, thanks to this, runoff water does not enter the plumbing.

Check valve for domestic sewage: dimensions

The dimensions of the check valves are selected depending on the diameter of the installed pipe. On the internal piping, as a rule, a PVC sewer check valve is mounted, since plastic models are easy to install, and most of the internal sewer pipes are made of the same material.
When installing a toilet, take a damper with a diameter of 110 mm, for a fan pipe or riser - from 160 to 200 mm, and for pipes that are located inside the building - 50 mm.

When an internal sewage system is installed, a 50 mm check valve is installed for no more than two plumbing fixtures, for example, for a washing machine and a sink. If desired, the check valve can be mounted separately on each plumbing fixture.

Check valve for outdoor sewage

A feature of the external sewage system in a private house is that these pipes have a large diameter, as well as strong pressure drops. Very often plastic sewerage is used. The check valve 110-200 mm is mainly used for connection to the central sewer riser. For powerful systems, as a rule, cast-iron pipes and a cast-iron ball check valve are mounted. They are quite reliable, more durable and do not need frequent cleaning. Valves can have a diameter ranging from 50 to 300 mm.

Check valves installed indoors are selected based on the conditions and rules for designing a waste system. The main ones are:

• compliance with the diameter of the pipe where they will be used;
• simplicity, ease of installation; in the event of various breakdowns, the structure can be replaced in a short time;
• the presence of an inspection hatch and forced closing of the mechanism.

Valve operation

Most check valves that are used indoors require maintenance (cleaning) from time to time. It is not recommended to make check valves for sewage with your own hands, since they can affect the correct operation of the entire system. The non-return valve installed on the external sewer system must meet the following requirements:

• have high mechanical strength, because the damper, as well as the entire sewer system, will be exposed to earth pressure from the outside;
• it must be securely connected to the main line;
• resist the impact of an aggressive environment;
• since access to it is limited, the implementation of preventive work has a long period.

It should be remembered that the check valve for internal sewerage should be, first of all, convenient in operation, and the external one should be reliable and not requiring constant cleaning.

Storm sewer

When designing storm sewers, one should take into account the possibility of overflowing water into containers for their accumulation. If the rainwater reservoir is leak-proof, if it is full, water may flow back. This can be avoided if a check valve is installed on the sewer. As a rule, they mount a plastic model for outdoor use.

Varieties of check valves

To date, check valves for sewerage are produced in several types, which are different both in design and in the range of use.

sewer air check valve

Air dampers are used to block odors from pipes and to stabilize the air pressure present in the system. The waste water enters the riser, where a rarefied background zone is formed, which needs to be stabilized with external pressure. In the absence of ventilation in the construction of the riser, the process passes through the internal piping.

The visible signs of this problem are:

• extraneous sounds that occur in plumbing fixtures: a special pat is heard.
• bad smell that comes from the plumbing.

The principle of operation of the sewer valve

The air valve works on the principle of supplying air to the sewer and preventing it from escaping back. The barrier is a membrane made of rubber and having a one-sided opening. When the water descends to the system, it opens under air pressure, allowing the drains to drain.

vacuum valve

They are used in houses where there is no ventilation pipe that goes outside, and to stabilize pressure. To install it, find the highest point of the riser and fix it vertically. Its design includes:

• air intake chamber;
• stock;
• rubber membrane.

When the pressure rises in the riser, the stem rises, releasing excess air.

Low pressure acts on the rubber membrane, and it opens, passing the amount of air necessary to stabilize.

ball valve

Ball valves have been used for a long time to protect against ingress of waste water, this is a very reliable and proven method over the years. Its design has:

• A passage chamber located at an acute angle to the movement of the drain water.
• A ball that is made of rubber or low-fat cast iron. It is in the blocking position in the absence of water in the system, and after it enters, it rises into the throughput chamber. The flow of sewage occurs due to the blocking of the hole in the pipe by the ball. It is it that is mounted on the external sewerage system and where there is a large throughput.

Check valve

It is used to avoid the backflow of suction water, as well as for oil systems, when pumping liquid, etc. It is mounted at the end of a vertically placed pumping station. It is not used for sewerage in residential buildings.

Reverse shutter

They operate on the same principle as shutter valves, however, they differ in their functional qualities. Its purpose is to block the return flow of sewage automatically, thanks to pressure sensors. If the sensors fail, the system is designed to manually block the flow of water. Check valves are installed in multi-storey and industrial buildings.

Wafer type valves

Installing check valves adds length to the entire pipeline, and this is not suitable for a large pipeline. If a wafer valve is used, the line size will not change significantly. Mount it between the connecting flanges of steel or cast iron pipes. It acts as a check valve. In the process of blocking, a flap mechanism is involved, which does not allow waste water to get back.

By design, wafer valves are divided into:

• single leaf;
• bivalve - they are mounted in the external sewage system.

The material used in the manufacture of the check valve

The material depends on the place where the check valve for the sewer (the photo is in the article) will be installed.

• Plastic. They are usually used in apartments.
• Cast iron. Basically, they are mounted on external sewerage, where the diameter of the pipes is more than 110 mm.
• Check valves are also widely used for various purposes, made of bronze and stainless steel.

Installation of non-return valves on the internal sewerage

To begin with, you should carefully read the instructions that are attached to the valves when they are sold. Installation includes several steps:

• Carry out measurements of large dimensions of the mechanism. They should be taken into account when designing a sewer and installing a valve in the pipe layout.
• In the old system, a section of pipe is cut that corresponds to the size obtained.
• Check the operation of the non-return valve before installation. To do this, it is necessary to lower the valve by force and pour water into the hole (outlet) of this device. In rare cases, leakage may occur.
• Install a water check valve. Use sealant and FUM tape for this work. On the case there is an arrow indicating the direction of movement of drains.

It is very important that the valve is ideally sized for the sewer and does not allow sewage to flow back.

Check valves for a pressure sewer system are installed immediately behind the pumping equipment. It is not recommended to mount them in other places, since artificial pressure will not allow them to work normally.

The installation of air check valves is carried out in rooms where the air temperature is above 0 °C.

Installation is carried out in various places of horizontal pipes, but the distance must be at least 10 cm from the highest point of the drains.

Valve prices

Their cost depends on:

• material used in production;
• design features;
• connection method;
• manufacturer.

Sewer check valves are an integral part of the entire sewer system. Only if all the standards are observed during the design, high-quality installation work and proper operation, the sewage system will perform its functions normally.