Underground Drainage FAQs
Do you produce large diameter underground pipe?
The largest underground pipe that we produce is 315mm (12 inches) in diameter. Polypipe Civils produce pipe up to 3000mm (3m) in diameter.
What is the stiffness rating of underground pipe?
- Smoothwall 110mm underground pipe has a ring stiffness classification of SN8
- Smoothwall 160mm underground pipe to BS EN 13476-2 has a ring stiffness classification of SN8
- Smoothwall 160mm underground pipe to BS EN 1401-1 has a ring stiffness classification of SN4
- Smoothwall 200mm, 250mm &315mm Sewerdrain underground pipe to EN 1401-1 has a ring stiffness classification of SN4
- Polysewer 150mm, 225mm & 300mm pipe to BS EN 13476-3 has a ring stiffness classification of SN8.
All the above are suitable for private or public drainage and adoptable applications as they are fully compliant with Sewerage Sector Guidance for England, Sewers for Scotland and The Welsh Minister Standards for Sewers.
What is the layout of the perforations on your perforated pipe?
Our perforated pipe has three rows of 6mm diameter holes, spaced at 75mm intervals, with a row in the centre and one at a 45º angle on either side.
How is 160mm Polysewer connected to 110mm smooth wall?
Use a PS621 Polysewer-to-smooth wall reducer.
What pressure is underground drainage tested to?
Underground draining is for gravity drainage only, and is so tested to only 0.5 bar.
How many Polystorm soakaway crates are required for my project?
Each standard Polystorm unit is 0.2m3 – 1.0m x 0.5m x 0.4m. Typically, a percolation test should be carried out to determine the rate at which water will drain. If this is not completed, it can be assumed that one unit will be suitable for up to 10m2, i.e. a 30m2 area will require three units (30/10=3). If a percolation test has been completed, the results should be passed to Polypipe Civils, who can carry out the necessary calculations.
Which Multi Y Junction should be used with the 60/80/100mm (HCC60/80/100)?
The 80 x 100mm Multi Y Junction (CDJ10M) is compatible with the 60/80/100mm land drain. It comes with all inlets/outlets reduced to 60mm and can be cut back to larger diameters as desired.
Does Polysewer come with seals?
All Polysewer products that have sockets come with seals. However, these are supplied separately and must be installed prior to laying.
What is the maximum temperature that PVCu underground can take
The maximum continuous flow temperature for PVCu underground pipe and fittings is 70°C, infrequent intermittent flow of up to 95°C for a period not exceeding one minute can be discharged to PVCu drain.