Fibre reinforced storage tanks for sodium hypo Fibre reinforced storage tanks for sodium hypo vjr0512 (Mechanical) (OP) 8 Nov 16 06:32 There is a proposal from vendor for the sodium hypo service storage ( day tank) in FRP material. Drawing is enclosed.I am concerned on the base plate arrangement of this tank. Thanks to provide a recommendation for a better design. http://files.engineering.com/getfile.aspx?folder=382be06e-f4a1-4885-b795-c9 RE: Fibre reinforced storage tanks for sodium hypo europipe (Chemical) 8 Nov 16 06:50 Don't think there is a problem, vinylester is very strong. However, des. press. must at least be 0.1 barg for that height. RE: Fibre reinforced storage tanks for sodium hypo EdClymer (Mechanical) 9 Nov 16 10:04 VJR0512 Item is a vertical, cylindrical, flat top vessel with base disc to plinth. Volume is small. Over pressure (+ve 500 Pa) and (-ve -1000 Pa) which make very little difference to bottom pressure of 0.0135 MPa (N/mm2). Depending upon code; this would indicate < 1 x 600 gms csm layer - but code minimum would apply (BS4994: 3 mm for static head and 5 mm for pressure) and (EN13121-3: 3 mm for static head and 5 mm for pressure) The cylindrical shell has to be linked/joined to base disc by interweaving/overlapping laminate in both directions, maybe plus additional laminate to form a knuckle (a short localised thicker region at the junction). This calculates to BS4994 (at F = 1.5 for 50 mm radius) no additional laminate required other than overlaps/interweaving. Calculated lengths (to shell and disc) are 43.7 mm (experience says 100 mm/150 mm minimum - more if hold-down lugs are to be secondary bonded to knuckle. The problem, is that a void is created inside the knuckle area on the bottom disc. Static head will tend to force bottom disc to plinth, and (given time) radial cracks will be initiated due to bending at about 200 mm from shell. There are two choices; 1) Bed tank to flat mass concrete plinth with a shallow cone of bitumen/sand (a mixture of fine aggregate/sand/ordinary portland cement and hot bitumen) this is a 'sqidgy' mix. Water is added to tank to remove entrapped air and within 24 hours bitsand will set hard - vessel is then fully supported. In UK we have great difficulty in obtaining bitsand (it always arrives on site cold). or; 2) During build, invert shell/disc (fully support) and flat fill with layers of chopped strand mat and resin. Then use two layers of decent bitumen roofing felt between underside of base disc and plinth. This is by far the cheaper option. Trust this is of help. PS: If anybody understands this post, and are trying to comprehend EN13121-3 (new European code - fourth attempt) could they make contact? Regards Ed Ed Clymer Resinfab & Associates England RE: Fibre reinforced storage tanks for sodium hypo bimr (Civil/Environmental) 9 Nov 16 21:10 What is the concentration of sodium hypochlorite?