G.F. (GoodForm) sectional water tanks are built to SS 245, and approved by the Public Utilities Board for domestic water use.
Our GRP sectional water tanks has high weathering resistance, and tank color remains unchanged.
It is far superior to pressed steel tanks in terms of heat and corrosion resistance.
Specifies the requirements for glass reinforced polyester sectional water tanks, called GRP sectional water tanks hereafter.
For the purpose of specification, the following shall apply:
Resin produced by condensation of one or more acids (including one or more unsaturated acids) with one or more polymor followed by co-polymerization with one or more cross-linking agent.
A GRP panel is a composite produced by a suitable process into specified dimensions.
Capacity of a GRP sectional water tank shall be within the range of 1,000 litres to 500,000 litres.
GRP sectional sectional water tanks shall be designed to have sufficient strength to withstand expected loads.
Panels for GRP sectional water tanks shall be bolted. Proper sealing materials shall be used for water tightness at bolted joints.
A GRP sectional water tank shall be provided with at least one manhole of not less than 0.6m inside diameter having an easily open cover with a lock to prevent rainwater from entering the tanks.
A GRP sectional water tank shall be provided with inlets, outlets, overflow, drains and air vents.
Nominal external size of unit panel shall be 1m square or 1m x 1.5m or 1.22m square.
Length and Breath of GRP sectional water tanks shall be specified as multiples of the nominal dimensions of either 1m or 1.22m.
Depth of GRP sectional water tanks shall be specified as 1m or 1.22m or 1.5m or 2m or 2.44m or 3m or 3.66m.
6. Service Requirements
Water tanks shall be designed for a temperature not exceeding 40°C.
Working pressure shall not be greater than the static head corresponding to the depth of the tank.
7. Composition of Panels
Material for the construction of panels are based on an unsaturated polyester resin. The unsaturated resin used shall be the condensation product of one or more acids (including one or more unsaturated acids) with one or more polhyols.
The condensation product must be soluble in one or more monomer and be co-polymerized with the use of organic peroxides.
The glass for construction of GRP sectional water tanks shall be non-alkali fibreglass conforming to BS 3396, BS 3496 and BS 3749.
The resin selected shall be suitable grade to meet the technical requirements for GRP water tanks or the minimum requirements in BS 3532.
Panels shall be manufactured with the combined double flange at an angle of 45° and 90° to the face of the panel on all four sides or a single flange at an angle of 90° to the face of the panel on each of the two, three or four sides, the flanges holed according to the respective position of the panel in the tank and free from irregularities.
The holes for the bolts shall have a clearance of 1.5 to 2.0mm in diameter.
Bolts and nuts used shall not be less than 10mm and shall be galvanized or surface treated against corrosion.
Sealing material used shall be non-toxic and chemically resistant to the quality of water stored. It shall also be able to withstand the temperature variation during service.
Interior supports shall be chemically resistant to the quality of water stored. They shall be made of stainless steel, GRP or mild steel completely coated with a suitable non-corrosive and non-toxic material. In addition, exterior supports shall be made of galvanized steel.
9. Components of GRP Sectional water tanks
Positions of these openings shall be subject to agreement between the purchaser and manufacturer. The dimensions of these openings shall comply with the requirements in BS 4504 for flanges and BS 21 for threads.
Air vents shall be designed and constructed to adequately inhibit entry of insects and other foreign materials into the water tanks.
Manhole hatch shall be made of GRP and its hinges shall be made of either aluminum alloy or stainless steel.
A GRP sectional water tank of 2m depth or more shall be provided with an internal ladder and an external galvanized mild steel ladder.