FEATURES - Braithwaite

1 The Braithwaite profile steel welded tank is designed to store large quantities of liquid, especially in remote or exposed locations. This tank is WRAS approved for the storage of potable water. Delivered in sections for welding on-site, profile steel welded tanks produce extremely strong and reliable storage vessels of unlimited capacity. They are increasingly specified by large volume users such as water authorities, hospitals, breweries and defence establishments. FEATURES . Rectangular shape makes best use of available space. Profile plates offer great strength with pleasing appearance. May be installed at or below ground level or on towers.

2 Tanks up to 5 metres high do not need internal supports apart from roof posts. Clear interior allows easy inspection, draining and painting. Manways, pipe connections and other fittings may be fitted and welded on site for positional accuracy. External and internal surfaces may be treated with a protective coating to suit most environments. The tank design can be tailored to suit individual requirements, taking into account the specific gravity of the liquid being stored, its pH value and temperature. HEALTH & SAFETY. Our safety consultants regularly visit our sites to report on working practices and equipment standards.

3 This ensures that site work is performed in a safe and workmanlike manner. QUALITY ASSURANCE. Braithwaite are certified to BS EN ISO 9001: 2000 and we pride ourselves on our commitment to both our quality of service and our products. 2. SPECIFICATION, DESIGN & MATERIALS. LOADINGS. (i) Tank cover (imposed loading): BS6399, Part 3: 1988. (ii) Tank cover, sides and base (wind loading): BS6399, Part 2*. *BS6399, Part 2 is to replace CP3; Chaper V: Part 2: 1972. DESIGN. (i) Tank base: BS799, Part 5: 1987, type J tanks*. *N/A for ring beam set in concrete base. (ii) Tank sides and cover: BS5950, Part 1: 1990. MATERIAL FINISH AND QUALITY.

4 (i) Welded structural steel: BS4360: 1990. BS5950, Part 2: 1992 Grade 43A. (ii) Protective coatinss: BS5493: 1977. (iii) Quality assurance: BS EN ISO 9001: 2000. Profile steel welded tanks are not designed as pressure vessels. They are designed to suit the hydrostatic pressure Braithwaite utilises state of the art CAD for design and induced by the liquid being stored. detailing for optimum efficiency. SURFACE PROTECTION. Materials are delivered to site in accordance with a phased programme and prior to despatch they are blast cleaned to BS 4232 second quality and painted with a weldable holding primer to give a measure of protection during transit and erection.

5 On completion of welding, the welds and all areas of abrasion and damage are flash blasted and patch primed before the application of paints selected to suit the tank contents and the external environment. For potable water tanks our standard WRAS approved site painting system is as follows. INTERNAL SURFACES. Flash blast all welds and abraded areas of shop primer and patch prime, then apply one coat of Epigrip L425HS. BITUMINOUS SAND zinc phosphate primer, followed by one coat of Epigrip Flat steel based tanks at ground level should be bedded M344 epoxy finish (nominal dry film thickness: 250. on bituminous sand, provided by the contractor.)

6 It microns). should be in accordance with BS2654, produced by hot mixing the following proportions by mass: EXTERNAL SURFACES. (a) 9 non-toxic cut back bitumen Flash blast all welds and abraded areas of shop primer ( fluxed with kerosene and not creosote) and patch prime, then apply a two-coat system of (b) 10 filler: either limestone dust passing a sieve Metanode chlorinated rubber paint (nominal dry film on nominal aperture size 75 m complying with thickness: 250 microns). BS410, or Portland cement. (c) 81 clean dry washed sand with the properties Drinking Water inspectorate approved linings can also given in table 2 of BS881, Part 2: 1973.

7 Be applied to the tank interior. 3. TANK WITH RING BEAM SET IN CONCRETE BASE. ERECTION SEQUENCE OF A POTABLE WATER TANK FOR A WATER AUTHORITY. 1. Base slab with ring-beam' in place. Waterproof membrane and reinforcing bars being positioned. 2. Surface concrete being poured, ring-beam' is cast in. 3. Sheets are delivered, first side erected and welded in place on ring-beam'. 4. Tank walls and divided nearing completion. 5. First roof cover plate is positioned. 6. Tank completed, cleaned and primed. 7. Tank fully externally painted, inspection ladder and guard railing fitted, plant room completed. 4. TANK WITH FLAT STEEL BASE ON STEEL TOWER.

8 EMERGENCY WATER TANK AT STEELWORKS. Gable Filling Peripheral Platform Rest Platform Foundation Blocks (By others). 1. Tank being assembled on site at ground level. 2. Tank is hoisted into position. 3. Final precision positioning on tower. 4. Tank interior fully finished showing manway and fixed access ladder. 5. SPECIFICATION, DESIGN & MATERIALS. TANK BASE AND SIDES. The following illustrates the three alternatives methods of tank base and side construction: 1. FLAT STEEL BASE ON BITUMINOUS SAND. Tanks are usually installed on reinforced concrete slab covered with a smooth bitumen-sand mix that is at least 50mm thick. The bituminous sand ensures correct levelling and bedding down, and protects the underside of the base against corrosion.

9 (See specification page 3). Flat base plates are overlapped and welded top side only. Profiled wall plates to the desired depth and metres wide are welded to each other and to the base inside and out, forming a very rigid container. 2. RING-BEAM SET IN CONCRETE BASE. For very large tanks it is often economically beneficial to eliminate the steel base and incorporate a ring-beam' into the reinforced concrete slab . Wall panels are welded directly to the beam. For the purposes of drainage it is sometimes desirable for the tank base to slope towards one end. In this situation a ring-beam' should be used. The slope can be incorporated in the concrete slab allowing the ring-beam' to be cast horizontally, thus simplifying fabrication and site erection.

10 3. FLAT STEEL BASE ON STEEL GRILLAGE. Tanks may be installed on steel grillage beams on bearer walls to allow access below the base or supported on tower bearers. TANK COVERS. Tanks can be provided with open top or with pitched covers. Where pitched covers are specified, construction is achieved by means of gable fillings fully welded to cover and walls. 6. TYPICAL TANK CAPACITY CHARTS. NOTE: These capacities are for standard sizes. Tank dimensions can be tailored to clients requirements. All capacities are shown nett without freeboard. Tank dimensions are to inside surfaces. Conversions: m3 to gallons: multiply by 220.