Seals for water technology

Seals in water technology are subject to specific technical requirements resulting from the medium, operating conditions and the application environment. Key criteria are a lasting sealing effect, consistent elasticity and resistance to water, additives and cleaning agents.

In water-carrying systems, changing pressures and temperatures act on the seals. The material used must compensate for these loads without changing its shape or function. Precise dimensional accuracy ensures that the seal continues to seal reliably even during long-term operation.

In applications involving drinking water, material compatibility is decisive. Seals used require appropriate approval for contact with drinking water and must not release any substances into the medium. In addition, ageing and hydrolysis resistance influence the service life.

The selection of the right seal therefore always depends on the specific application. An unsuitable choice of material often leads to premature wear or leaks in the system.

Further information on material-related properties can be found in the overview of materials for seals.

Suitable materials for seals in water technology

The choice of the right material determines the functional reliability of seals in water technology applications. Material compatibility, temperature and pressure resistance as well as ageing behaviour under continuous load are decisive. Depending on the area of application, different elastomers are used.

EPDM is frequently used in water technology. The material offers high resistance to water, steam and many cleaning agents and is suitable for applications involving drinking water and industrial water. EPDM is also characterised by good ageing and ozone resistance.

NBR is used primarily in systems in which oils or greases occur in addition to water. The material offers good mechanical load capacity, but is only suitable to a limited extent for pure drinking water applications.

Silicone is used when high or strongly fluctuating temperatures occur. The material remains elastic over a wide temperature range and is therefore used in special water technology applications.

The choice of material is always application-related. In addition to the medium, the installation situation, movements in the system and legal requirements play a central role.

A detailed overview of available materials can be found in the materials for seals section.

Typical designs and seal types in water technology

Different designs of seals are used in water technology, each tailored to specific installation situations and loads. The choice of the right seal design influences assembly, sealing effect and maintenance effort.

O-rings are frequently used in valves, pumps and housings. They are suitable for static and dynamic applications and, when correctly designed, provide uniform surface pressure. In water technology, O-rings are used primarily in EPDM or suitable silicone grades.

Flat gaskets are typically used in flange connections. They compensate for unevenness in the sealing surfaces and are suitable for large-area sealing in pipeline systems. Material thickness and surface pressure are decisive for the sealing function here.

Moulded seals are used when standardised seal shapes do not cover the installation situation. They are adapted precisely to the geometry and function of the component and are used in complex water technology assemblies.

The choice of seal design is always made in conjunction with material, installation space and mechanical stress. Early coordination reduces assembly errors and increases operational reliability.

Further information on available seal types can be found in the seals overview.

Areas of application for seals in water technology

Seals in water technology are used in various plants and components in which water is safely conveyed, regulated or stored. The respective area of application determines the requirements for material, design and layout.

In pumps, seals ensure the sealing of housings, shafts and connections. They must reliably absorb pressure fluctuations and movements and ensure a consistent sealing effect during continuous operation.

Pipeline systems require seals that remain permanently tight and compensate for assembly inaccuracies. Flange connections, couplings and transitions place different demands on material and seal geometry.

In valves such as shut-off valves, gate valves or isolating devices, seals perform both static and dynamic sealing functions. Recurring movements and changing pressure conditions frequently act here.

In plant engineering in water technology, seals are used in complex assemblies in which several media, temperatures or pressure stages may occur. A coordinated choice of seal supports the operational reliability of the entire plant.

Supplementary information on application-related solutions can be found in the seals section.

Custom manufacturing and cut pieces for water technology

In water technology, standard seals are often not sufficient, as installation spaces, connection geometries or loads are designed individually. Custom manufacturing and precise cut pieces enable a precisely fitting seal even for complex or project-specific requirements.

Moulded seals are manufactured on the basis of technical drawings, samples or CAD data. Contours, material thicknesses and tolerances can be matched exactly to the respective application. This supports reproducible quality across production runs.

Cut pieces from sealing sheets are frequently used for flange connections or large-area sealing. Precise manufacturing processes preserve dimensional accuracy and surface quality, which facilitates assembly and stabilises the sealing effect.

Custom-made seals are suitable both for individual pieces and for small-batch and series production. They are used wherever function, service life and operational reliability are the priority.

Further information on individual solutions can be found in the moulded seals section.

Approvals and standards in water technology

In water technology, seals are subject to clearly defined normative and legal requirements. These relate in particular to applications involving drinking water as well as plants that are used permanently in public or industrial operation. Approvals create legal certainty and support consistent product quality.

For contact with drinking water, only materials that have been tested and approved accordingly may be used. These include, among others, national and European regulations that assess the migration of substances and hygienic suitability.

In addition to drinking water requirements, technical standards also play a role, defining dimensions, tolerances and test methods. They facilitate the comparability of products and support safe integration into existing systems.

Compliance with relevant standards is particularly important in plant engineering and for safety-relevant components. It forms the basis for acceptances, documentation and long-term operation.

Supplementary information on material-related requirements can be found in the materials for seals overview.

Selection guide for seals in water technology

The selection of a suitable seal in water technology is based on clear technical criteria. The medium, temperature range, operating pressure and mechanical stress in the installed state are decisive. A structured approach reduces failure risks and increases operational reliability.

First, it must be determined which water the seal is in contact with. Drinking water, industrial water or process water place different demands on material compatibility and approvals. Possible additives or cleaning agents must also be taken into account.

The available installation space determines the possible seal design. Dimensional accuracy, groove geometry and surface condition directly influence the sealing effect. Deviations in these areas frequently lead to leaks or premature wear.

Typical errors arise from a blanket choice of material or from transferring solutions from other areas of application. An application-related coordination of material and design supports stable function over the entire service life.

An overview of available seal types and materials is provided in the seals section.

Advice and technical support for seals in water technology

The design of seals in water technology requires technical expertise and a precise examination of the respective application. Professional advice supports the selection of suitable materials, designs and dimensions on the basis of real operating conditions.

Technical support often begins already in the planning phase. On the basis of drawings, samples or application data, seals can be designed in a targeted manner and adapted to the installation situation. This applies both to standard applications and to special solutions.

Samples and prototypes enable practical testing before series use. They support the assessment of assembly, fit and sealing effect under real conditions and reduce risks in later operation.

For complex projects in water technology, technical coordination accompanies the entire process from selection to series production. This supports consistent quality and reliable function in use.

Further information on individual solutions can be found in the moulded seals section.

Seals for water technology – summary

Seals perform a central function in water technology for the safe and lasting operation of water-carrying systems. Requirements for material, design and layout result from the medium, operating conditions and regulatory requirements.

An application-related selection supports the functional reliability of pumps, pipelines, valves and plants over long periods. Custom manufacturing and precise cut pieces enable solutions even for complex installation situations or project-specific requirements.

Consideration of relevant standards and approvals forms the basis for legally compliant and technically clean use. Early technical coordination reduces failure risks and supports stable plant operation.

An overview of available solutions and materials is provided in the seals section.

Frequently asked questions about seals in water technology

Which seals are suitable for drinking water applications?

For drinking water applications, seals are used whose materials are approved for contact with drinking water. Tested materials with defined migration and appropriate suitability for long-term use are decisive.

Which materials are most commonly used in water technology?

In water technology, elastomers such as EPDM are used above all. Depending on the application, NBR or silicone are used in addition where special requirements exist regarding temperature or mechanical load.

Are custom manufacturing options also possible for small quantities?

Custom-made seals are suitable both for individual pieces and for small-batch and series production. The basis is formed by technical drawings, samples or CAD data.

Which factors influence the service life of seals?

The service life is determined by the medium, temperature, pressure, mechanical stress and the choice of material. An application-related design supports stable function over long periods.

Do technical advice and samples support the selection?

Technical advice supports the selection of suitable seals. Samples and prototypes enable testing of fit and sealing effect before use in ongoing operation.