Design features and rules for installing a vacuum valve for sewage


The sew­er sys­tem does not always work per­fect­ly. Espe­cial­ly when it comes to apart­ment build­ings with worn-out com­mu­ni­ca­tions.

The cause of many trou­bles with sew­er­age is relat­ed to the pres­sure dif­fer­ence with­in the sys­tem. If sev­er­al plumb­ing out­lets are con­nect­ed to a com­mon pipe at once, then, for exam­ple, flush­ing the toi­let bowl can pull out the water seal in the sink siphon. As a result, unpleas­ant odors from the gen­er­al sys­tem will be drawn into the hole that has appeared.

The most effec­tive way to reg­u­late the pres­sure in the pipes is the fan valve installed for the sew­er. It can work both as an out­let and as an inlet. Most often, it is tak­en out with a spe­cial pipe to a well-ven­ti­lat­ed place: out­side the house through the roof or wall and away from win­dows (accord­ing to the norms, at least 4 meters).

Scheme of instal­la­tion and oper­a­tion of the fan pipe

But such a sys­tem has sig­nif­i­cant dis­ad­van­tages, which main­ly con­sist in the high cost of work and con­struc­tive com­plex­i­ty. So, the fan pipe is removed from the com­mon ris­er and installed at the time of con­struc­tion of the build­ing.

When the fan pipe starts to work inter­mit­tent­ly (it clogs, micro­c­racks form in it that vio­late the tight­ness), in some places where plumb­ing is con­nect­ed, the pres­sure is no longer always con­stant.

As opposed to a sol­id fan sys­tem, one of the eas­i­est and most afford­able ways to get rid of sew­er odor is to install a sim­ple vac­u­um valve. For its prop­er instal­la­tion, you also need to know some secrets, but this device can pro­vide high-qual­i­ty work and quite effec­tive­ly cope with 2–3 con­nect­ed bath­rooms.

Sim­ple Vac­u­um Check Valve

Design features and principle of operation of the vacuum valve for sewage


You can also install a con­ven­tion­al vac­u­um-type sew­er valve with your own hands. The device is sold assem­bled, and the only dif­fi­cul­ty that lies in the instal­la­tion is its tight con­nec­tion with the sew­er pipe.

The valve is per­fect for instal­la­tion on the sew­er in a pri­vate house or apart­ment — where there are few bath­rooms and the load on the drain is quite small. Then he will be quite effec­tive in doing his job.

Impor­tant! The vac­u­um valve for the sew­er or as it is also called — the aer­a­tor — must be installed in a well-ven­ti­lat­ed area. It is desir­able that there is a win­dow 4–5 meters away. In apart­ments, gen­er­al ven­ti­la­tion is suit­able, the draft of which can be enhanced by an elec­tric fan.

The prin­ci­ple of oper­a­tion of the vac­u­um valve is that, accord­ing to the laws of physics, warm air rush­es to the top points. The sew­er pipe sys­tem also has cav­i­ties that fill with foul-smelling air. Prop­er­ly planned com­mu­ni­ca­tions are dis­tin­guished by the fact that the place of con­cen­tra­tion of air con­ges­tion is pro­vid­ed with holes that would equal­ize pres­sure drops.

Anoth­er issue is that an ordi­nary hole would con­stant­ly bleed air, and some­times let liq­uids out, caus­ing leaks and flood­ing. To avoid this, the shut-off valve used for sewage is made one-way. That is, a flap is installed on it, which can let air in from the out­side in the open state. In nor­mal mode, or when the pres­sure inside the sew­er sys­tem ris­es, the valve is her­met­i­cal­ly closed.

The valve of a con­ven­tion­al vac­u­um boost­er is designed as sim­ply as pos­si­ble. Most often, its mem­brane is made of rub­ber and is a con­ven­tion­al gas­ket that reli­ably cov­ers the tech­ni­cal hole in the inter­nal sew­er­age sys­tem.

Inter­est­ing! The cheap­est option is to use a clas­sic rub­ber mem­brane in the valve. But in the process of work, this mate­r­i­al can quick­ly become unus­able and per­form its func­tions worse. Expen­sive vac­u­um valves may use mod­ern tech­nol­o­gy. For exam­ple, poly­mer com­pounds that have not vio­lat­ed the tight­ness of the sew­er for years, with­out los­ing qual­i­ty at all. Or the device is com­ple­ment­ed by a stem, which is fine­ly tuned to respond to pres­sure drops.

The valve con­sists of:

  • corps;
  • inter­nal open­ing for air pas­sage;
  • a rod that is con­fig­ured in such a way as to fix the pres­sure drop in the pipes and out­side, open­ing or clos­ing the mem­brane;
  • mem­branes;
  • pro­tec­tive cov­er.

Schemat­i­cal­ly, the oper­a­tion of the valve looks like this:

Scheme of work

On one of the side faces of the device there is a hole for com­mu­ni­ca­tion with the air in the room. On some mod­els, the recep­ta­cle may be top-mount­ed or under a cov­er cap.

Inside the vac­u­um valve there is a hol­low space through which air can move freely. In the dia­gram, the red arrows show the vapors from the sew­er. They can­not get into the room, as they encounter an obsta­cle in the form of a rub­ber mem­brane (left fig­ure). When the pres­sure in the pipe sys­tem drops seri­ous­ly, the mem­brane ris­es due to the air pres­sure from the room (gray arrows). At the moment when the pres­sure equal­izes, the rub­ber gas­ket low­ers again, ensur­ing the tight­ness of the sys­tem.

Vacuum valve installation rules


Accord­ing to build­ing codes, the exhaust sew­er must be a fan. This is under­stood on the basis of the fol­low­ing require­ments:

  • Any type of sew­er sys­tem (for indus­tri­al and domes­tic needs) must be ven­ti­lat­ed through ris­ers of the same diam­e­ter as the main pipe.
  • The out­let should not lead to a com­mon shaft for ven­ti­la­tion, but should lead through the roof — to the street, 4 meters or more from win­dows and bal­conies.
  • A fan pipe can com­bine sev­er­al ris­ers with a sew­er.

It turns out that build­ing codes do not reg­u­late the instal­la­tion of a sim­ple vac­u­um valve. There­fore, each own­er can decide on its instal­la­tion inde­pen­dent­ly.

Such a valve can come in handy on the low­er floors of apart­ment build­ings (where a water seal of a toi­let bowl or a siphon can be sucked in) due to the fre­quent use of sew­er­age by neigh­bors. It is known that with inten­sive drain­ing, the suc­tion capac­i­ty of the pipe is up to 30 vol­umes of the water that is col­lect­ed in plumb­ing to block odor. In this case, the valve is indis­pens­able.

In a pri­vate house, it is also cus­tom­ary to install vac­u­um valves when sev­er­al out­lets are used at once in one sew­er pipe (bath, 1–2 sinks, 1–2 toi­lets).

There are some sim­ple tips for installing an effec­tive air vent on your sew­er. In fact, their device is prac­ti­cal­ly no dif­fer­ent from each oth­er, but a lot depends on how well the instal­la­tion is car­ried out.

  • To begin with, the tight­ness of the equip­ment is checked. For this, a con­ven­tion­al bicy­cle or car pump is suit­able. If you treat the mem­brane with soap or dip it in water and blow the sys­tem in the oppo­site direc­tion, then the result­ing air bub­bles will clear­ly indi­cate that the elas­tic band does not close the hole as it should.
  • Install the vac­u­um valve only in a ver­ti­cal posi­tion. So it will work as effi­cient­ly as pos­si­ble.
  • The valve should have good air access, but the cre­ation of quick access for repairs should not be neglect­ed either.
  • The aer­a­tor is locat­ed at least 30 cen­time­ters above the junc­tion with the ris­er. Adapters and pipe bends are used for con­nec­tion.
  • There are two types of aer­a­tors: 50 and 110 mm in diam­e­ter. The for­mer are rec­om­mend­ed to be placed on out­lets from siphons and local drains, and the lat­ter on the main sew­er pipe.
50 mm aer­a­tor
110 mm aer­a­tor
  • The valve can be installed direct­ly on the pipe in two ways: by screw­ing it onto a pre-cut thread or using a sock­et treat­ed with sealant.
Mod­el with thread­ed noz­zle


Before instal­la­tion, you need to turn off the water in the house, and then insert a suit­able elbow adapter on the pipe. The junc­tion of the air valve and the sew­er pipe is thor­ough­ly cleaned of con­t­a­m­i­nants in order to main­tain the tight­ness of the sys­tem. Of the tools at hand, you need to have suit­able wrench­es, sealant, a met­al saw.

Dur­ing oper­a­tion, the device prac­ti­cal­ly does not require repair, since its device is as sim­ple as pos­si­ble. The only prob­lems that some­times arise is the wear of the rub­ber mem­brane. But chang­ing it is usu­al­ly a mat­ter of a few min­utes.

Cor­ru­gat­ed Mod­el

Pros and cons of a vacuum valve

The most impor­tant advan­tage of using a vac­u­um valve is that it is designed to max­i­mize cost sav­ings when repair­ing a sew­er sys­tem. The fan pipe will be sev­er­al times more expen­sive, as it requires seri­ous rede­vel­op­ment and the pur­chase of a large amount of mate­ri­als.

  • Also, a valve with a mem­brane will sig­nif­i­cant­ly improve the per­for­mance of the sewage sys­tem.
  • High ener­gy effi­cien­cy will be achieved (heat loss­es in the pip­ing sys­tem will not be as high as with a fan pipe).
  • Instal­la­tion is easy, straight­for­ward and fast.

But at the same time, it would be a lit­tle sil­ly to believe that a vac­u­um valve is a panacea for all sew­er ills. Yes, besides it, there is noth­ing else to use in apart­ment build­ings where there is no fan pipe. Also, only this device will sig­nif­i­cant­ly reduce the esti­mate of a pri­vate house (where a fan ris­er is not entire­ly appro­pri­ate due to the low load on the sew­er).

But the air valve is rec­om­mend­ed to be installed when there are not so many out­lets to the plumb­ing. Ide­al­ly two or three. Oth­er­wise, it will not always with­stand the load and the smell from the sew­er will still enter the premis­es through the torn off hydraulic locks.


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