110mm drainage fittings - 90 degree inspection bend?

[alistairolsen]

Hi,

If I have put this in the wrong subforum, sorry! It seemed more appropriate to building than the plumbing and hot water topics.

Last weekend I had the delightful job of clearing blocked drains around my house (rural, septic tank, private drains etc.) and in the process, after a lot of digging, found a 90 degree junction whic had been achieved using a right angle tee with a screw on cover on the redundant leg; all of which was then buried - No chance of that working then!

I have one of these elsewhere in the system (albeit with one leg), in the bottom of a nice concrete manhole:
http://www.mytub.co.uk/4d492-osma-s-s-equ-dbl-insp-junction-45d-product-616430

I'd like to do similar here, with a 90 degree radiused bend to replace the current tee, but the only similar fitting I can find is a Marley UBR45, which seems to be available only in New Zealand....
http://www.marleypipesystems.co.za/bends

Does anyone know of anywhere I can buy a 90 degree bend with an inspection hatch in the UK?

Thanks
Al

 

[freddiemercurystwin]

Or just fit a rodding eye at ground level to the redundant cap end

But really a 90° bend should be avoided if possible ie a bigger radius.

Then the next poor sod won't have to dig up the garden to clear it.

 

[alistairolsen]

Thanks for the reply

I don't really want a rodding point if I can avoid it as it still leaves the redundant leg to take the energy out of the water and catch solids and start the blockage, hence the radiused bend.

I appreciated a bigger radius would be better, but due to its location, short of digging up half the drive to relocate other connections, it's not going to happen.

It's all going to be left in a proper manhole so it can be accessed for rodding later.

The other option is a bend with the top cut open and haunched with concrete, but the inspection bend just seems cleaner and nicer.

Cheers

 

[r896neo]

Forget about redundant legs, It would be better to use a Y branch but have your inflow into the branch and have the outflow discharging out of one end and the rodding eye out the other.

 

[alistairolsen]

So the Connection I'm looking at is the manhole between the kitchen and the bedroom (where the manhole was evidently never built:

https://www.dropbox.com/s/w7bohfk6z29dxiu/IMG_20150222_194054.jpg

After some digging, I found this:
https://www.dropbox.com/s/5xkx2y7die30kyf/IMG_20150302_081607.jpg

The other manhole is under an area of decking, with a hatch and an inpsection connector like I posted in my first post.

So without digging up lots, I have limited scope for increasing the radius before Im under the house, and limited scope for changing the angle of the pipes to make them meet a Y section.

I could install a rodding point as suggested, but it's in gravel down to 3 inches of so and at risk of being parked on with a front wheel, hence preferring a proper manhole (otherwise I pretty much need to set the rodding point in concrete anyway)

Hopefully it makes a little more sense?

 

[r896neo]

A Y and a 45 bend is not going to be a large affair.

A rodding eye is a small solid, usually galvanised steel thing and can safely be parked on.

The optimum would be a small 300mm IC.

 

[Hugh Jaleak]

If you're installing a manhole anyway, then just use a preformed plastic chamber. I wouldn't bother with sealed access, can get messy if it blocks and you have to get down there to undo it. Then it doesn't always seal again....

Chamber diameter will need to be decided according to depth of sewer at that point. Up to 600mm then a smaller chamber is ok, deeper than 600mm and you'll need the larger 450mm diameter chamber.

 

[oldbutnotdead]

Not suggesting these are the best or the only source but this (with a lid and a riser) is solving a similar problem for me

http://www.plastics-express.co.uk/460mm-diameter-chamber-base-284-side-inlets29-p-pte362a

 

[alistairolsen]

A Y and a 45 bend is not going to be a large affair.

A rodding eye is a small solid, usually galvanised steel thing and can safely be parked on.

The optimum would be a small 300mm IC.

Yes, but surely not if all thats holding it up is the pipe?

These plastic inspection chambers look like a reasonable alternative, but again, will they break up if someone drives over it?

It's not deep at all, but is there any harm in fitting the larger one?

Thanks for all the advice!

 

[oldbutnotdead]

Well at 35kN loading as long as the trench work is up to scratch then it should be fine.
And using the bigger one- no problem at all (well that's what local BCO told me)- he was quite pleased with that 90 degree entry, other option was a 45 degree manhole with a 45 degree bend which would be more prone to blockages.

 

[Hugh Jaleak]

Larger chamber is easier to work from if required, hence why the smaller diameter chambers are restricted to 600mm deep. Smaller chambers are cheaper, so often used where possible to cut costs. If the drains are that shallow though under a driveway I would be looking at the existing cover to ensure they are adequately protected.

If your chamber is subject to vehicle loading you can always surround it with concrete to add extra protection, but provided it has been installed correctly, and the base suitably supported then you may only need a driveway loading cover on it.

 

[r896neo]

Yes, but surely not if all thats holding it up is the pipe?

If your trench is filled properly and the rodding eye set on a bed of concrete as it would always be then where shall it move to?

 

[alistairolsen]

Yes, but surely not if all thats holding it up is the pipe?

If your trench is filled properly and the rodding eye set on a bed of concrete as it would always be then where shall it move to?

Thanks for all the replies folks.

It's looking like a chamber is a good way to go, not cheap though!

Well the pipe is set in gravel, in the earth by the look of things, and then that earth is covered in membrane and then gravel, so shoprt of a large concrete slab laid specifically to hold the rodding point, its going to be floating around in gravel, which under vehicle loads basically behaves as a fluid.

 

[r896neo]

The gravel doesn't behave like a fluid because it is restrained inside the trench.

The actual rodding cover is set in concrete though.