DVGW, WRAS, BAM, KTW —
what these approvals actually mean
It tells you what the material has been tested against and where the approval may be relevant. It does not automatically approve every installation condition. Using a gasket material without the required documentation in a regulated application is not just a technical risk. It can become a compliance and liability problem.
Documentation scope: Approval, compliance and certification references apply to the documented material grade, supplier certificate or listing, and stated test conditions unless a product-specific certificate says otherwise. A cut gasket size is not automatically certified as a separate product just because it is made from a documented material. For regulated applications, confirm the current certificate or listing scope, exact grade, medium, temperature, pressure and market requirement before specifying.
Why this matters more than most people think
Most installers see approval codes on a datasheet and move on. The gasket fits the size, the price is right, the job gets done. That works — until it doesn't.
An approval is not the whole decision. It is the first gate. It tells you where a material may be allowed to start. It does not finish the selection for you.
When a joint fails in a regulated system — potable water, gas, food processing — the first question is not what brand the gasket was. It is whether the material was approved for that application. If the answer is no, the installer, contractor or specifier may carry the consequence. The datasheet cannot rescue a wrong application.
Approval, listing and test references are evidence with a defined owner, date, product identity and scope. The acronym alone is not proof that the supplied cut gasket is currently covered.
The basic rule: if the application is regulated — gas, potable water, food contact — the gasket material grade needs the relevant documentation or approval scope for that market and service condition. Fit first, check later is not a strategy. It is a risk transfer.
The four approvals you will see most often
DVGW is the German technical and scientific association for gas and water. Its approval scheme covers materials, components and equipment used in gas and drinking water installations. A gasket made from a DVGW-documented material grade has been assessed within a defined scope to confirm the material does not compromise the specified medium under the tested conditions.
In practice, for many gas applications across Germany, Austria and much of Central Europe, DVGW is the baseline approval buyers and specifiers expect to see. It is also relevant for drinking water applications in these markets — a DVGW water approval or related material documentation confirms the assessed material grade does not leach substances beyond the stated limits under the tested conditions.
WRAS is the UK approval scheme for products and materials that come into contact with drinking water. A WRAS-listed product or material has been tested against the Water Supply (Water Fittings) Regulations 1999, but only within the approval scope, listed conditions and maximum water temperature stated in the listing.
In UK potable water work, WRAS is the approval most specifiers and water undertakers look for. It plays a similar specifier role for UK drinking-water work, but it is not interchangeable with DVGW schemes or current German KTW-BWGL conformity evidence.
Specifying outside WRAS requirements in a regulated UK water installation is worth taking seriously — water undertakers can require remedial work if non-compliant materials are found during inspection.
BAM is the German Federal Institute for Materials Research and Testing. In the context of sealing materials, BAM documentation is specifically relevant for oxygen service. Oxygen under pressure is an extreme environment — materials that perform safely in air or nitrogen can ignite or accelerate combustion in pressurised oxygen.
A gasket made from a BAM-documented material grade has been tested under defined report conditions. It is not a blanket oxygen clearance; the tested pressure, temperature, oxygen medium and report scope must match the duty. In industrial gas systems, medical gas lines or any process where oxygen is present under pressure, that scope check is the relevant requirement.
If you are specifying for oxygen service and the material does not carry BAM documentation for the required scope, it should not be used — regardless of what other documents it holds.
KTW is legacy shorthand in German drinking-water work. Current organic-material checks belong against the applicable KTW-BWGL criteria and a current product-specific conformity document. The German Environment Agency (UBA) defines evaluation criteria but does not itself approve or certify products.
As of July 2026, an old KTW notation on a supplier sheet should not be presented as current German product conformity. Obtain the current certificate or attestation for the exact supplied grade, product form and contact conditions, assessed against the requirements that apply on the installation date.
Hygiene criteria, product certification and any separate technical-system requirement have different scopes. Check each requirement named by the project instead of treating one logo or legacy reference as a substitute for the others.
Which approval do you actually need
The approval you need is determined by the application — not by what is available on the shelf. Three questions give the answer quickly.
What is the medium? Potable water, gas, oxygen, food contact — each has its own approval framework. A material grade documented for drinking water is not automatically documented for gas. A grade documented for gas is not automatically suitable for oxygen service.
What market is the installation in? WRAS is a common UK drinking-water approval route where specified. German work may call for a DVGW scheme, current KTW-BWGL conformity evidence or both, depending on the product and specification. These routes are not interchangeable; confirm the exact requirement before selection.
Is the application regulated? Potable water, gas and oxygen duties may impose legal, scheme or project-specific evidence requirements. Establish which one applies; an approval is mandatory only within the framework that actually governs the installation.
Supplier-sheet references — verify the current certificate
| Series | DVGW | WRAS | BAM | Supplier KTW ref. | FDA |
|---|---|---|---|---|---|
| GREENSEAL PRO 180 | — | — | — | ✓ | ✓ |
| BLUESEAL ULTRA 350 | ✓ | ✓ | ✓ | — | — |
| FLEXSEAL PRO 350 | ✓ | ✓ | — | — | — |
| GRAPHITESEAL ULTRA 350 | — | — | ✓ | — | — |
| REDSEAL PRO 110 | — | ✓ | — | — | — |
| RUBBERSEAL PRO 110 | — | — | — | — | — |
This matrix records references found in the mapped supplier sheets; it is not a current certificate register and does not certify every cut size. Obtain the applicable document for the exact supplied grade, product form, market and service before specifying.
What an approval does not tell you
An approval or compliance reference confirms the documented material grade has been tested for a specific medium under specific conditions. It does not tell you the material is right for every application within that medium.
An approval does not make a gasket right. It makes it eligible. Wrong approval is not a detail — it is a risk. Fit by size and price alone, and you are guessing.
A WRAS-listed gasket has drinking-water documentation only for its listed scope, conditions and maximum water temperature. It is not automatically rated for every pressure, temperature or chemical combination in a water system. The listing is the starting point; the datasheet and the actual service conditions decide whether it is the right choice.
Read the approval. Then read the datasheet. The approval opens the door. The datasheet tells you whether to walk through it.
One practical rule: if you are unsure whether an approval covers your application, it probably does not. Ask for the full technical datasheet, check the approval scope, and if the application is regulated, confirm with the relevant authority before specifying.
An approval code on a box is a starting point, not a guarantee.
Field check before specifying:
1. Identify the medium (gas, potable water, oxygen, food contact) and the market (UK, DE, EU, other).
2. Match the approval to the medium and market — do not substitute approvals across categories.
3. Confirm the approval is current. Schemes are renewed; check the certificate date on the technical datasheet.
4. Read the approval scope. A WRAS approval may cover a product or material at ambient potable-water conditions but not at hot-water service conditions — the listing scope tells you the boundary.
Approvals are not paperwork. They are the evidence that someone tested the material against your application.
DVGW, WRAS and BAM references each have scheme- and document-specific boundaries. KTW is a legacy German shorthand; current German organic-material evidence must be checked against the applicable KTW-BWGL framework and exact product certificate. Identify the governing requirement before the gasket is selected.
Current datasheets and applicable material documentation by Kinetics Line series are available via the B2B section.
Practical FAQ
Is DVGW the same as WRAS?
No. DVGW is the German technical and scientific association for gas and water — its approvals and material documentation are used for gas and drinking water in Central European markets. WRAS is a common UK approval route for products and materials that contact drinking water under the Water Supply (Water Fittings) Regulations 1999. They are not automatically interchangeable for regulatory purposes.
What does BAM approval mean for a gasket?
BAM documentation means the gasket material has been tested by the Bundesanstalt für Materialforschung und -prüfung for oxygen service under stated report conditions. Check tested pressure, temperature, oxygen medium and report scope before specifying.
Do I need both DVGW and KTW for drinking water?
Not in every market. KTW is the legacy German hygiene reference for elastomeric or plastic materials in drinking-water contact; current checks should reference KTW-BWGL / UBA where applicable. DVGW water approval or documentation covers the stated material or system scope. In the UK, WRAS is a common drinking-water reference where specified.