Inspection chamber diameter reduction

[BotusBuild]

I have two installed inspection chambers of 600mm diameter both of which are to be reduced in height following a landscaping design change. As part of that change we're also looking to reduce the drain cover size to 320 or 350mm still allowing access for any required clearing.

 

I can find plenty of access restriction or shaft reducing caps, but none of these look like they are designed to allow a change from one riser diameter to another e.g 600mm to 320/350mm (hope the next diagram explains it a bit more)

 

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Anyone know of a suitable "riser diameter changer" product?

[Nickfromwales]

4 hours ago, BotusBuild said:

I have two installed inspection chambers of 600mm diameter both of which are to be reduced in height following a landscaping design change. As part of that change we're also looking to reduce the drain cover size to 320 or 350mm still allowing access for any required clearing.

 

I can find plenty of access restriction or shaft reducing caps, but none of these look like they are designed to allow a change from one riser diameter to another e.g 600mm to 320/350mm (hope the next diagram explains it a bit more)

 

     |    |

___|    |___

|               |

|               |

 

Anyone know of a suitable "riser diameter changer" product?

Price is horrific, but shop around. 
 

https://www.drainagesuperstore.co.uk/product/axedo-600mm-to-350mm-inspection-chamber-restrictor-ring.html?clickref=1100lDp3y34Q&reqid=73079187&affid=1694&app_clickref=1100lDp3y34Q

[BotusBuild]

Yeah, seen those, but it seems there is no ability to then add 320mm or 350mm riser on top of it. Something like this:

 

https://www.tradepipes.co.uk/320mm-diameter-chamber-riser-135mm-high?source=googlebase&msclkid=d5cfa3ce6b6b1d0776b3c94ae6007d73&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping Campaign&utm_term=4577816667752085&utm_content=Underground Drainage

[Nickfromwales]

1 hour ago, BotusBuild said:

Yeah, seen those, but it seems there is no ability to then add 320mm or 350mm riser on top of it. Something like this:

 

https://www.tradepipes.co.uk/320mm-diameter-chamber-riser-135mm-high?source=googlebase&msclkid=d5cfa3ce6b6b1d0776b3c94ae6007d73&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping Campaign&utm_term=4577816667752085&utm_content=Underground Drainage

There must be, as it would need to take a modular access cover. 
 

Ring them on Tuesday and ask for a solution.