Old fashion soil and waste vent

[lettywetty]

Hi,

I found buried under the ground in my front garden an old fashion waste vent, next to it lies a manhole to which the vent is connected.
I removed the soil that had accumulaated in the vent and its piece of pipe conneted to the manhole.
The vent has no more flap, it must have been removed before being buried because there are still 2 bits of metal stuck under the screws.
This is a square metal old fashion vent. I don't know how it is called and how to search for it on Internet ( on google, I tried soils and waste vent, waste vent, and I don't get it)
I could I suppose install there anything like a grid but if I can find the exact piece missing on the market, I would like to buy it.
How do you call tha vent and where can I find the flap missing? My vent looks like this one:

Thanks. Letty

 

[lettywetty]

Hi,
Can anyone tell me how you call this piece and where I can find a flap for it?
Thanks.

 

[Madrab]

Where did you get the pic from? That's an unusual vent cap for a cast SV pipe, you may find it easier to go to a blacksmith and have a flap made up.

 

[lettywetty]

I was looking on Internet for an ordinary kind of thing like that. I tried to Google "drain vent" and found that image. This is the kind of thing I found in my garden except that mine is a simple greyish metallic one (we bought an old bungalow for the '30s". I need a normal flap for it or a grid as the cap is not there anymore but I cannot find anything like that on Internet as I don't how you call that thing!! There must be things like that in Wickes or Screwfix for sure, no? I know it is an old fashion thing for the drain.
Could you tell me?
My husband wants to diy a grid to block the hole but i am sure that we can find a flap for it.
Thanks.

 

[Newboy]

The flaps used to be made of mica (back in the good old days!) and I would think the chances of finding a replacement are almost zero.

The vent you have is an old AAV used to relieve negative pressure in the chamber.

The only risk you have of re-installing it without an airtight flap is that you will allow it to vent sewer gases.

 

[JimCrow]

Vent Flap Valve

http://www.cadia.com.au/materials-and-supplies/other-valves-and-strainers/mica-vent-flap-valve

 

[Madrab]

That is a specialist cast iron vent that you have and not something you could buy off the shelf at one of the sheds I'm afraid. The site you got the picture from would be the guys to talk to. Bespoke cast stuff is not cheap tho.

http://www.castironairbricks.co.uk/product/sewar-vent-grille-with-flap/

 

[lettywetty]

I will need to look on Google what this eans exactly. But tell me, what shall we do with that now, re-bury it, block it completly? It must have been blocked for years.

 

[Madrab]

Can you take a pic of the installation so we can see what it's position/orientation is to the manhole? It may have been added as a supplementary vent for the sewer.

 

[Steelmasons]

Can you take a pic of the installation so we can see what it's position/orientation is to the manhole? It may have been added as a supplementary vent for the sewer.

Very common to see these in the front garden within close proximity of manhole..

 

[Steelmasons]

Where did you get the pic from? That's an unusual vent cap for a cast SV pipe, you may find it easier to go to a blacksmith and have a flap made up.

It was never intended to be used as a soil and vent terminal..

 

[Madrab]

So what were they used for then Steel, a supplementary vent for the sewer run? Why have they screw tabs on the back too, that suggests it's to be screwed to a wall, say on the top of a vent Can't say I've ever seen one up here tho.

 

[Bosswhite]

Could be an obsolete venting cap for a septic tank .

 

[Steelmasons]

Many were affixed to gate post in front garden or affixed to front garden wall/house wall (using the lugs).
Plenty of these around London especially Hampstead/Haringey...
A vent pipe was taken from the top of manhole (just below manhole cover) and terminated as above.
These were used in order relieve any negative pressure within drainage system (interceptor etc).
They were positioned at ground level..

 

[Hugh Jaleak]

Common fitment up until the late 40's, with the use of the interceptor (or Buchan trap as some refer to them), the idea was the house drains would be sealed off from the main sewer in the road. These low level vents were installed on the last chamber before the road, that contained the interceptor on the outgoing drain, with the idea that air passing over the top of the soil and vent pipe, would cause a negative pressure in the house drainage system.
This would then cause air to be drawn in the low level vent, and thus ventilate the house drains.

They soon broke, the mica flaps fell off, or jammed open, so visitors were often greeted by the smell of the drains at the gate. With the loss of the stoppers in the interceptor rodding eyes, this only compounded the problem. Best idea is to seal the outlet from the manhole off with some decent strength concrete, to stop rats using it as a front door, and then remove the vent completely, and bury/remove remaining pipework as required. There was a previous discussion here: http://www.diynot.com/diy/threads/sewer-drain-ventilation-advice-required-please.297016/