The Kiwa Water Mark is needed when you, as a producer or supplier, want to profile yourself on the market with products that meet all requirements: all functional requirements as well as all legal hygienic requirements specified in the “Materials and chemicals in the supply of drinking water and warm tap water Regulation” of the Dutch government.

The internally tinned copper tubes are intended to be used in the transport of hot (≤90 °C) or cold water intended for human consumption. The tubes can be supplied in the annealed, half hard and hard material temper conditions.

The internal tinning of copper tubes is intended to reduce the migration of copper into the drinking water, for those applications where this could be a point of consideration. The tube connections can only be made with the help of tinned copper press fittings or tinned copper alloyed press fittings conforming to the requirements of evaluation guideline BRL-K774, or with tinned soft-solder fittings conforming to the requirements of evaluation guideline BRL-K623.

Tube connections made by drift expanding the tube shall not be allowed.

Due to an increased risk of corrosion caused by excessive heat input it is not allowed to hard solder these tubes. Also, it is not permitted to hot bend or use any other kind of process where the excessive input of heat is required.

Depending on the tinning process an external tin layer may also be applied to the tube. However, this external tin layer is not a consideration for this evaluation guideline

Soft soldering of fittings in accordance with BRL K623 is limited to DN 54 mm. maximum


Steps to obtain a certificate with the Kiwa Water Mark are:
1. Fill in an application form  and send it to Kiwa (application form is located on the right side);
2. Kiwa sends a quotation, which is at the same time a concept-agreement, drawn up according to the requirements of the guideline;
3. After mutual signing of the quotation, the agreement is definitive and the initial audit can start;
4. After positive results of the initial audit, the certificate will be issued;
5. The certificate is valid indefinitely;
6. A part of the agreement is periodic audits.

Important aspects of the initial audit (steps 3 and 4) include:
a.Testing with regard to the product and/or performance requirements. Testing, often carried out in our own laboratories, demonstrates that the product meets the certification requirements for functional and hygienic aspects, such as durability, dimensions, composition of materials, etc.;
b. Assessment of the production process, quality system and internal quality control (IQC) scheme. To ascertain that the producer is continually able to manufacture products that meet the certification requirements.

The periodic audits aim at the maintenance of the management system, in order to maintain confidence that the producer is still able to manufacture products that meet the certification requirements. The periodic audits include functional and hygienic tests of the certified products. The audit frequency varies from product group to product group: in general, 2 to 4 times per year.

Conditions for the certification process are stated in the Kiwa Regulations for Product Certification and the General Terms and Conditions of Kiwa for the performance of orders.