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GRP Sectional Water Tanks


Grp Sectional cold water storage tanks                                                                                                        

Purewater Storage we can supply a broad range of high quality GRP Sectional water tanks. These are an ideal solution when it comes to storing large volumes of water.

Purewater GRP Sectional tanks are designed in a modular format which allows for a comprehensive range of tank sizes and configurations. Sectional tanks comprise of individual bolt-up panels which are assembled on site.

GRP Sectional Tanks are designed for two specific applications:

  • For storing water in large capacities - from 125 litres up to 2,000,000 litres
  • To allow the site assembly of a cold water storage tank where access restrictions or other conditions deny the installation of one and two piece tanks

Our selection of GRP Sectional tanks feature a broad range of features including:

  • Hot press moulded GRP panels, ensuring maximum dimensional stability and consistency of quality
  • WRAS approval
  • The purewater one-piece raised float valve housing panel, complete with screened spill over weir, providing an AB air gap and 830 x 830mm access to the float valve
  • The industry's largest sized man-way access at 830 x 830mm aperture
  • A metric modular format allowing water storage from 125 litres to 2,000,000 litres
  • Factory Pre-insulated including insulated base option, providing a U value of 0.8w/m²/deg.c

At Purewater Storage we provide GRP Sectional Tanks of only the highest possible standard. These are manufactured to BS EN 13280:2001, and in compliance with an ISO9001:2001 quality control system.

The sectional tank range is available in a number of different formats too. With an internal or externally flanged base arrangement, also with a fully self draining base option.

They are also assembled on site by our own fully skilled and equipped engineers, ensuring 100% control of installation. Purewater DO NOT utilise outsourced labour to assemble sectional tanks.

Sectional tank formats comprise:

Internally Flanged Base Tanks (IFB)

The most cost effective sectional tank format suitable for:

  • Positioning onto a flat, solid,level & continuous foundation
  • Applications where there is sufficient working room all around the tank


  • An Internally flanged base, externally flanged sides, internally flanged roof
  • Insulation to the sides and cover only

IFB tanks are suitable for positioning onto a flat, level and continuous foundation, normally a structural concrete slab.

For assembly IFB tanks require a minimum of 500mm working clearance all around the external dimensions of the tank, and a minimum of 600mm above the man-way.

Externally Flanged Base Tanks (EFB)

These tanks are suitable for:

  • Positioning onto raised supports, typically to provide a positive head of pressure to an adjacent pump set or similar equipment
  • Where an insulated base is required
  • They are also ideal for applications where there is sufficient working room all around the tank


  • Externally flanged base, externally flanged sides, internally flanged roof.
  • Insulated to the base, sides and cover.
  • EFB tanks are suitable for positioning onto raised supports at 1000mm or 500mm centres depending on the tank size and configuration, foundation normally comprises of brick built or concrete dwarf walls.

Raised supports must be a minimum of 500mm high.

For assembly EFB tanks require a minimum of 500mm working clearance all around the external dimensions of the tank, and a minimum of 600mm above the man-way.

Totally Internally Flanged Tanks (TIF)

TIF tanks are suitable for a diverse range of uses, including in applications where:

  • There is minimal working room available
  • All panel joint flanges are accessed from inside the tank
  • There is a requirement for positioning onto a flat level & continuous foundation


  • Internally flanged base, internally flanged sides, internally flanged roof.
  • Insulated to the sides and cover.
  • TIF tanks are suitable for positioning onto a flat, level and continuous foundation, normally a structural concrete slab

For assembly TIF tanks require a minimum of 50mm working clearance around the external dimensions of three faces of the tank and 500mm to the remaining face of the tank, and a minimum of 600mm above the man-way.

Tank Foundation Requirements

Where foundation tolerances are not within specification, or if erecting metric configuration tanks on an existing imperial configured support, Purewater can supply the necessary steelwork to enable installation of the tank.

Steelwork can be shimmed by our own engineers prior to installation of the tank.

Marine grade ply base boards can also be supplied to enable internally flanged tanks to be installed on supports when no flat base option is available on site.

All foundation areas are inspected and checked using laser measuring equipment prior to tank installation too, giving you great peace of mind. 

Panel Specification

Our panels are manufactured from high quality SMC material hot pressed moulded to a temperature of 150°c, ensuring maximum dimensional stability.

  • Panels are also available in a metric format, panels being 1000 x 1000mm, 1000 x 500mm & 500 x 500mm.
  • Individual panels are dimensionally accurate with defined sharp corners, and are precision factory drilled.
  • We also offer a truncated panel option for maximum strength and to provide full metre span base configuration.
  • They feature a maximum size Manway access panel with 830 x 830mm aperture.In addition to a purpose designed one-piece raised float valve housing panel complete with screened spill over weir to ensure AB type air gap configuration.

Our panels are also

  • Factory Pre-insulated using 25mm CFC free polyurethane foam providing a U value of 0.83 n/m²
  • Fully WRAS approved 
  • Manufactured under ISO 9002 approval

Access Manway

The Purewater one-piece manway panel has a considerable 830 x 830mm access aperture. This ensures maximum space for ease of movement, and provides the largest access hatch available in the industry.

Raised Float Valve Housing

Purewater sectional tanks are supplied with a one-piece raised float valve housing panel which forms part of the roof structure in the same way as a standard roof panel. The inspection hatch opening is again a considerable 830 x 830mm offering the same access benefits as the standard manway.

Raised Float valve housings can be supplied complete with screened spill over weirs to ensure AB air gap compliance. All Purewater spill over weirs are shrouded to prevent light ingress, thus helping to prevent the growth of algae and other organisms.


All internal fixings are A4 grade stainless steel, external fixings are either galvanized or A4 grade stainless steel.

Bracing System

Bracing where required is provided by high grade box section steel uprights located at each vertical panel joint. Uprights are fixed using threaded stainless steel tie rods and further secured with angle brackets to the outside of the tank. All external steel components are hot dip galvanized.

Our unique bracing system allows for maximum unobstructed movement within the tank. What's more the system also provides unequalled simplicity for future cleaning operations.

For tanks with internal divisions, Purewater use stainless steel for all uprights and associated reinforcement to divider panels throughout.

Internal Divisions

Internal dividers can be fitted, providing two compartments enabling easy maintenance of the tanks without interruption of water supply.

Dividers are constructed from GRP tank panels and are supported by stainless steel bracing and fixings.

Tank Assembly

Assembly of Purewater GRP Sectional tanks is carried out by our own high skilled engineers. A full base inspection is undertaken before assembly can commence. Specification calls for exacting tolerances; therefore laser level equipment is also used, ensuring precision and accuracy from the start.

Our engineers can fit all necessary float valves, connections and other ancillary items to the tank. Purewater will accurately install float valves ensuring correct positioning of the valve in relation to overflows and spill over screen units, thus ensuring correct AB air gap configuration.

Purewater guarantee to work safely, efficiently and with respect to other site workers. Our engineers will remove all related packaging and similar waste items, ensuring a clean area when the job is completed.

Additional Services

Purewater also offer the following services:

  • Site survey prior to works commencing
  • Strip out of existing tanks and equipment
  • Base inspection using laser level equipment
  • Pre-commission cleaning and chlorination including samples and certification
  • Full commissioning of tanks and equipment

Contact Purewater Storage - The GRP Sectional Water Tank Specialists

If you require further information regarding our GRP sectional water tank options, or any of the other products that we offer, please don't hesitate to contact us here at Purewater Storage on 0121 323 4000, and one of our advisors will be happy to assist you with your enquiries.

For more information please download our information documents below:

Purewater Sectional WRAS cert 2019.pdf

CWST Operations Maintenance Manual

On site connection fitting instructions 

Grp Sectional Tanks - Hot press moulded 

General Conditions Of Installation Sectional tanks