Technical features and application of the check valve for sewage


The sew­er­age sys­tem is designed for the time­ly drain of waste prod­ucts using a toi­let bowl. One of the nec­es­sary ele­ments of the sys­tem is a check valve for fan pipes — struc­tural­ly it is sim­i­lar to a tra­di­tion­al check valve for plumb­ing, but it func­tions a lit­tle dif­fer­ent­ly. Instal­la­tion on the sew­er will help to avoid the back­flow of waste, keep­ing the repairs in the apart­ment intact. Instal­la­tion is car­ried out in apart­ments of mul­ti-storey res­i­den­tial build­ings, in pri­vate hous­es.

Check valve design: characteristics

The sew­er check valve device con­sists of sev­er­al ele­ments:

  1. Cov­er — designed to facil­i­tate the oper­a­tion and repair of the struc­ture.
  2. Latch — holds the damper in the desired posi­tion.
  3. Damper — pre­vents the reverse flow of waste from the pipe.
  4. Bell — rep­re­sent­ed by two options — input and out­put. The first is con­nect­ed at the inlet to the sys­tem, the sec­ond — at the out­let to the main sew­er pipe.
  5. Ball — used in some mod­els instead of a damper. Made from vul­can­ized rub­ber mate­r­i­al.
  6. The body is the shell of the entire struc­ture, which is made of var­i­ous mate­ri­als that pre­vent defor­ma­tion and are resis­tant to impacts from the inside and out­side.
The prod­uct is installed in a ver­ti­cal or hor­i­zon­tal posi­tion on a sew­er pipe

The device of a mod­ern sew­er check valve is rep­re­sent­ed by the indi­cat­ed details. All mod­els may dif­fer from each oth­er in shape, mate­r­i­al of pro­duc­tion, method of instal­la­tion, as well as oper­at­ing tem­per­a­ture. Some prod­ucts are designed for out­door use, oth­ers for res­i­den­tial and indoor use. Today, mod­els with a diam­e­ter of 50 and 110 mm are on sale.

The principle of operation of the device

For res­i­dents of the low­er floors in mul­ti-storey build­ings, the erup­tion of sewage from the toi­let is a com­mon acci­dent. To pre­vent such a sit­u­a­tion, plumbers offer to put the prod­uct on the sew­er. It works like this:

  • inside the device is a ball mech­a­nism or damper;
  • with a nor­mal direct flow of water, this valve allows water to pass into the pipe, pro­vid­ing a drain;
  • if an emer­gency occurs and a reverse flow of water occurs, then the damper is under pres­sure;
  • the mem­brane com­plete­ly blocks the flow of water into the pipe, and it does not flow back into the toi­let;
  • the design avoids the erup­tion of sewage from the toi­let, there­by pro­tect­ing the apart­ment from dan­ger­ous sit­u­a­tions.
Scheme of oper­a­tion of the check valve


The prin­ci­ple of oper­a­tion of the sew­er ball check valve implies time­ly main­te­nance and clean­ing of the device. If you do not revise the device, then its func­tion­ing will dete­ri­o­rate, and if a reverse flow of water occurs in the pres­sure sew­er, the mass­es can come to the sur­face of the toi­let bowl and end up out­side it. To clean the struc­ture, it is nec­es­sary to open the top cov­er on the body: through it you can access the lock­ing mech­a­nism and clean it from dirt. The valve is mount­ed at the junc­tion of two pipes: it can be made on a hor­i­zon­tal and ver­ti­cal pipe.

Types of sewer valves

There is a wide vari­ety of non-return valves for the sew­er sys­tem on the plumb­ing mar­ket. They dif­fer in the place of instal­la­tion, instal­la­tion method, as well as in the mate­r­i­al of pro­duc­tion.

By place of application

Accord­ing to the loca­tion of the struc­ture, check valves are used on the street sew­er sys­tem and on the inter­nal one locat­ed in the apart­ment. For exam­ple, for exter­nal sewage, a diam­e­ter of 110, 160 and 200 mm is used. These are large wide pipes, on which a prod­uct with a man­u­al lock and a fuse is installed. The mod­el is installed in a hor­i­zon­tal posi­tion on the street or in the base­ment. Inside the prod­uct is equipped with a stain­less damper.

Valves for instal­la­tion inside the apart­ment can be used in two ways:

  • install one device on the sew­er pipe;
  • install sev­er­al ele­ments on each plumb­ing fix­ture.
Prod­uct device with dimen­sions in the draw­ing


The sec­ond option will cost more, and the first requires a sig­nif­i­cant amount of space to fit the device into the sew­er pipe. A diam­e­ter of 50 mm is used for indi­vid­ual instal­la­tion on appli­ances, and a pipe diam­e­ter of 110 mm is used when installed on a com­mon drain pipe.

According to the installation method

Accord­ing to the instal­la­tion method, sew­er check valves can be divid­ed into:

  • flanged;
  • inter­flange;
  • cou­pling.

The first type is installed on the pipeline using a flange con­nec­tion. The device is com­plet­ed with mat­ing flanges and spe­cial fas­ten­ers. The design can be made with a lift­ing, disk, ball or rotary valve. On three sides there are plates on which bolts should be locat­ed, form­ing a flange con­nec­tion. Often these mod­els are made of cast iron.

Wafer valves are small in size and low in cost. Dur­ing instal­la­tion, this type of valve is fixed between pipeline flanges. This type is eas­i­ly dis­man­tled, replace­ment of parts is quick and has­sle-free. The inter­nal mech­a­nism of such mod­els is rep­re­sent­ed by disc and dou­ble-leaf shut­ters.

Anoth­er type of sew­er check valve — cou­pling or thread­ed

From the name it is clear that the mount is rep­re­sent­ed by a thread. Often the pro­duc­tion uses stain­less steel, cast iron and brass. There are two main types of con­struc­tion, the peo­ple call them “rock­er” and “bar­rel”.

According to the material of manufacture

For the pro­duc­tion of check valves for the sew­er ris­er, the same mate­ri­als are used as for the man­u­fac­ture of pipes. The struc­tures are:

  1. Cast iron — used on main sew­er sys­tems, more often installed on large diam­e­ter pipes. Mod­els are able to with­stand strong pres­sure with­out defor­ma­tion.
  2. Plas­tic — the most pop­u­lar type for instal­la­tion on intra-apart­ment sys­tems. Afford­able and easy to install devices.
  3. Steel — used on out­door sys­tems, resis­tant to cor­ro­sion, not exposed to aggres­sive envi­ron­ments.
  4. Bronze — have a long ser­vice life, as well as good resis­tance to exter­nal fac­tors. They are expen­sive com­pared to oth­er options.
Shut-off valves will work on the prin­ci­ple of expo­sure to the pres­sure of water in the pipe

All the options pre­sent­ed are dis­tin­guished by good func­tion­ing, but each type must be used for its intend­ed pur­pose.

Criteria for choosing a non-return valve for sewerage


It is good if the plumb­ing mas­ter will be engaged in the choice of the desired valve. If the own­er of the apart­ment decid­ed to inde­pen­dent­ly find the desired design, it is rec­om­mend­ed to pay atten­tion to:

  1. The sec­tion of the sock­et — this indi­ca­tor must exact­ly match the sec­tion of the sock­et of the sew­er pipe: there should be no gaps.
  2. Mate­r­i­al — the raw mate­ri­als for the man­u­fac­ture of the valve must match the raw mate­ri­als for the pro­duc­tion of pipes: it is not rec­om­mend­ed to mount a plas­tic valve on steel pipes.
  3. Dimen­sions — it is worth con­sid­er­ing not only the diam­e­ter of the pipe, but also the exter­nal dimen­sions of the valve: it must organ­i­cal­ly fit into the allot­ted space.
  4. Instal­la­tion — it is worth choos­ing the type of instal­la­tion that is more prefer­able for the exist­ing pipeline.
  5. Qual­i­ty of mate­ri­als — before buy­ing it is nec­es­sary to clar­i­fy the guar­an­tee for the prod­uct.
  6. Cost — the price does not depend on its exter­nal design or func­tion­al­i­ty: when form­ing the cost, the man­u­fac­tur­er focus­es on the mate­r­i­al for pro­duc­tion.
When choos­ing, pay atten­tion to the diam­e­ter of the device

It is nec­es­sary to pur­chase valves in trust­ed stores and out­lets: domes­tic-made devices are not infe­ri­or in qual­i­ty to for­eign options.

Product installation features


You can install a check valve on the sew­er with your own hands. It is not dif­fi­cult to do this, the main thing is to pre­pare a num­ber of tools and fol­low the step-by-step instal­la­tion instruc­tions. Expert advice will help you avoid mis­takes.

Instrument preparation

To inde­pen­dent­ly mount the device on the pipeline, you will need the fol­low­ing mate­ri­als and tools:

  • check valve for sew­er­age;
  • con­struc­tion knife for cut­ting plas­tic pipes on a hor­i­zon­tal or ver­ti­cal ris­er;
  • build­ing lev­el: the valve must be installed strict­ly accord­ing to the stan­dards;
  • var­i­ous fas­ten­ers.
Depend­ing on the method of mount­ing the valve, some of the fas­ten­ers may be includ­ed with the prod­uct.

If the man­u­fac­tur­er did not equip the device with fas­ten­ers, then you need to pre­pare self-tap­ping screws, dow­els and plas­tic clamps.

Step by step installation of the valve


Instal­la­tion of a fan valve for con­sti­pa­tion from the reverse flow of water is car­ried out in sev­er­al steps:

  1. Choice of loca­tion. For instal­la­tion, the junc­tion of the sew­er pipe and the toi­let bowl or the point of con­tact of two pipes is suit­able.
  2. If the device is mount­ed hor­i­zon­tal­ly, then it is nec­es­sary to set the lev­el. If the instal­la­tion takes place in a ver­ti­cal pipeline, then the angle of incli­na­tion does not mat­ter.
  3. The sys­tem is assem­bled in such a way that the sock­ets are direct­ed in the oppo­site direc­tion to the water flow.
  4. O‑rings and gas­kets must be used. If desired, you can use sealed glue.
  5. To install a non-return valve on the sew­er your­self, pre­vent­ing its vibra­tion in the future, it is rec­om­mend­ed to use clamps to fix the device on a wall or floor.
An unnec­es­sary piece of pipe can be removed with a grinder

Instal­la­tion does not require spe­cial skills — it can be done by hand with­in 1–2 hours.

Expert advice

In order to avoid mis­takes dur­ing instal­la­tion and oper­a­tion, it is nec­es­sary to heed the advice of plumb­ing spe­cial­ists. For exam­ple, when installing a valve with an elec­tric dri­ve, it is nec­es­sary to pre­pare in advance the place and access to the pow­er sup­ply to the device. The place­ment of the device must be in accor­dance with safe­ty stan­dards.

In order for the con­sti­pa­tion to work prop­er­ly before instal­la­tion, it is impor­tant to study the instruc­tions and find out if there is a need for instal­la­tion in a strict­ly indi­cat­ed posi­tion. Installing plas­tic con­sti­pa­tion on cast iron pipes is allowed only if adapters are used. If the valve has become unus­able, it is bet­ter to com­plete­ly replace the instal­la­tion than to look for parts to repair the prod­uct, risk­ing an emer­gency sit­u­a­tion.

Check valves are a nec­es­sary ele­ment of the sew­er sys­tem in an apart­ment and a house. You can install it on your own, it will not take much time, but the own­er of the home will be sure of his safe­ty.


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