What is DWI?

The Drinking Water Inspectorate (DWI) carries out approval processes for the Authorities of the UK (DEFRA) under the relevant regulations for each of the 4 Nations. The DWI deals with products/parts that will come into contact with drinking water up to the point of delivery to the premises, but not including water supply systems inside buildings, this is dealt with under WRAS.

Basis for Approval of a (Coating) Material

When a company such as Northpoint wants to provide coating services to pipe and water equipment handling manufactures, they have to put the proposed material, coating material in Northpoint’s case, through an approval process. Applications can be complex and so are handled by experts who will assess the nature of the coating product and if it meets the standard (BS 6920). Once the coating material has performed to meet the specifics of the BS 6920 standard, an application in the correct form will be processed, and Instructions for Use (IFU) document will be produced in an approved form. Only after all steps have been completed will DEFRA then consider the product for inclusion on the list of Approved Products.

List of Approved Products

Approved products are listed for a 5 year period, and must be reviewed by DEFRA every 5 years to remain on the list. Once approved, the DWI will formally write to the approval holder providing confirmation that the named product is approved, each product having its own listing reference (e.g. Northpoint’s Resicoat FBE coating reference is DWI 56.4.659).

The approval is given as:

“Approval given under Regulation 31 (4)(a) of the Water Supply (Water Quality) Regulations 2016 Si No. 614 (as amended) and the Water Supply (Water Quality) Regulations 2018 Si No. 647 (W.121)”

The full list of approved products can be found at; DWI Approved List of Products

The fees associated with the approval process have to be met by the applying company and there is no guarantee of approval, approval is given on the basis of the evidence meeting the exacting standards required.

Northpoint’s Capability

Northpoint has been an applicator of corrosion protection coatings since the late 1970’s and has a wealth of experience to draw on. Northpoint presently has 3 products DWI Reg. 31 (4)(a) approved for use as a coating service:

  • Resicoat R4 – DWI 56.4.659 – an FBE coating
  • Jotaguard VA 5001 – DWI 56.4.1304 – an FBE coating
  • Eurokote 468 Thixo – DWI 56.4.1209 – an Epoxy coating

In recent years, Northpoint has pioneered the application of Fusion Bonded Epoxy (FBE) coatings, with Liquid Epoxy coatings such as Eurokote 468 Thixo as a solution aimed at reducing drag and turbulence of long stretches of pipe lines. Effectively the coating reduces the amount of energy needed to pump water over extended distances, whilst providing the steel pipework with corrosion protection with a design life of circa 50 years in many instances.

New innovation includes the application of a UV protective layer over the external FBE coating. Epoxy coatings generally (including FBE coatings) will fade when in direct sunlight. Whilst this won’t materially affect the performance of the FBE or Epoxy coating in contact with water, it can become unsightly over time. Northpoint has developed a coating system that combats the discolouration  process meaning that the large capital investment made remains looking like new for years to come.

Northpoint also holds WRAS Approval on the Jotaguard VA 5001 product, providing a solution for pipework coating designed for inside a building, which can be offered along-side the DWI solutions.

WIMES Coatings

Some requirements may fall under the WIMES Standard, which again is part of Northpoint’s capabilities. Our engineers are able to understand specific customer requirements and provide a coating system that will meet the standards too. Coatings under the WIMES standard will be quoted as:

“Water Industry Mechanical and Electrical Specification 4.01 – Paints and Polymeric Coatings for Corrosion Protection”

This standard provides an outline for how the application of coatings is to be managed. It goes on to provide a number of tables that describe coating systems that meet differing parts of ISO 12944 C3 – C5M/C5I requirements and Imm 1 – 4 requirements.

In all cases, Northpoint’s coating inspectors act as independents to the process and are qualified NACE II Coatings Inspectors, supervised by a NACE III Coatings Inspector who will cross-check and pass-off their work and, where contracted, provide inspection services as per the customer requirements.

Northpoint’s Facility & People

The Northpoint facility has 3 fluidised beds for the application of FBE coatings depending on specific customer needs. Northpoint also has spray facilities designed to handle items such as slip-on flanges and smaller easier to handle pipes.

In addition to the FBE application processes, Northpoint operates a state-of-the-art SprayBake Booth (spray booth LEV with oven capabilities) and a range of application equipment including Graco Merkur 45:1 air assisted airless, Graco XTreme 60:1 airless & Graco XM 2k Plural. Key staff members have been professionally trained and meet the requirements of SSPC Train the Painter Scheme, alongside Coatings Inspectors qualified to NACE I, II & III and ICorr L2. It is in this area that the Eurokote 468 Thixo and the UV protective coatings are applied.

Other Applications for Northpoint’s Coatings

Northpoint has the capability and experience to offer coating services that meet the demands of the Oil, Gas and Air industries. Northpoint’s capabilities extend to the application of NORSOK coatings and specialist industry coatings that meet the demands of SaudiAramoc and KOC specifications.

If you’re looking for corrosion protection, DWI approved coatings or a paint system for your parts then Northpoint will have a solution that meets your needs. Email our team sales@northpointltd.uk today or call us to discuss your requirements.