Drainage Non-Return Valve - 160mm
Non-return valves are used in a drainage system to protect the installation against the possibility of back flow from the main drain.
They are an ideal addition to any drainage system that is installed within a potential flood area.
Non-return valves are also a useful tool for preventing rodent entry into a house drain.
160mm Underground Drainage
160mm underground drainage is most commonly used for a collection of flows from the 110mm pipes that flow into it. The range of fittings available in 160mm is generally smaller than the 110mm range, as a run of 160mm drainage is usually more direct and with fewer connections than 110mm pipe.
The fall required in a 160mm pipe depends on the peak flow in litres per second (as with 110mm pipes), but as a rule of thumb the fall it is shallower than that required for a 110mm pipe. The composition of backfill used can also be different, with slightly larger aggregate fill (pea shingle) being allowable for a 160mm pipe installation. Both of these criteria should be checked with local building control prior to installation.
In terms of installation and connecting pipes to fittings, the process is the same as with 110mm pipes. Cut pipes should always be chamfered prior to insertion into a fitting, and seals should be lubricated with silicon spray or grease.
160mm drainage is often still referred to as, reflecting the old comparative imperial size that was used. As this old pipe was commonly made from clay or salt glaze, flexible rubber adaptors are now available to make a straightforward connection from this old material to PVC.