Filter tank with inside piping and mounted flange adaptor (as cement socket) for further piping. With nozzle plate in GRP (vinylester) and filter nozzles in PP (polypropylene). 191 filter nozzles (nozzle plates to DIN have only 152 nozzles), for an improved flow during backwash. Nozzles with fine slots 0.25mm, allow the use of sand grain sizes of 0.4 - 0.8mm without support layer. Purge air connection optionally possible. A water distributor (sludge hopper Ø 400 mm) in GRP. Cylindrical filter tank, vertical, in fibre-glass reinforced polyester resin. Manufactured using a special manual lamination process. On GRP base ring. Entirely homogenous overall construction, exclusively in GRP. High resistance to pressure and high elasticity, suitable for continuous operation. The used isophthalic acid resins are completely resistant to chemicals (with the exception of ozone) and food-safe. Tank surface (gel coat) solid-coloured, with UV protection, especially scratch-resistant and insensitive to mechanical and chemical stress. Inner finishing layer of tank made of highly scratch-resistant and abrasion-proof isophthalic acid resin coating (gel coat). Acid proof and alkaline resistant. Large filling and maintenance port in upper tank floor including lid, diameter 500 mm. Lateral maintenance port with lid, diameter 500 mm in cylindrical shell. Revision port with lid in lower tank floor diameter 150 mm. Lid filling and maintenance port made of GRP. Lid revision port made of plastic (nylon). All lids with O-ring sealing and mounting accessories. Acrylic inspection glass for checking the filter surface, glass placed above the lateral maintenance port. Viewing glass dimensions 55 x 245 mm. Including o_ring sealing and mounting accessories. Colour: yellow - RAL 1021 Guarantee 5 years