pharmaceutical sealing solutions

The pharmaceutical industry includes the manufacture, extraction, processing, purification, and packaging of chemical materials to be used as medication for humans or animals. Pharmaceutical manufacturing is divided into two major stages. The first stage, which is typically referred to as primary processing or manufacture, is the production of the active ingredient or drug. The second stage, secondary processing, is the conversion of the active drugs into products suitable for administration.Throughout each and every stage, the importance of contamination elimination cannot be over looked.

High performance materials for demanding Pharmaceutical applications

With pharmaceutical sealing, materials need to demonstrate a range of properties including chemical compatibility, high temperature resistance, abrasion resistance and the capability to withstand aggressive cleaning regimes. The requirements for seal robustness are very high, for example, in tablet production where powders are processed.

During the production of chemically produced drugs API (Active Pharmaceutical Ingredients) or in vivo diagnostics (contrast agents, biomarkers), chemicals and toxic substances are used. Throughout organic synthesis, high temperatures and high pressures occur, whereas cooling (and low temperatures) takes place during the precipitation of the product.The temperature range is therefore quite substantial.

Because of the diverse demands of the Pharmaceutical industry, a number of high performance materials are required to satisfy the demand for superior chemical sealing, reliability and long service life:


Due to its outstanding resistance to water and water-based systems, EPDM is one of the most frequently used sealing materials. In addition to black materials, white EPDM is available to support hygienic processes

FFKM (perfluoroelastomers)*

FFKM are suited to extreme operating conditions due to their unique media and temperature resistance. As a result, they are mainly used in the chemical industry. White FFKM satisfies both the demanding operating conditions and supports hygienic processes.

Viton / FKM*

Various compounding processes enable precise formulations for the required media resistance and low-temperature flexibility. For example, Viton GLT temperature range is-40°C to +205°C and allows for use in demanding applications.

Nitrile and  Hydrogenated Nitrile**

Nitrile (NBR) and Hydrogenated Nitrile (HNBR) materials are distinguished by their good low-temperature flexibility and their low abrasion. As a result, they are suited for applications involving a high input of energy into the seal.


Silicone rubber (VMQ) has been traditionally used in applications where especially pure materials are required. Furthermore, it can be used in a wide range of temperatures.


PTFE materials are impressive for their extremely high resistance in nearly all media and their capacity for individual adaptations. The flat gasket material ePTFE (expanded PTFE) is distinguished by its unique flexibility and purity.

*USP Class VI and FDA grades available. ** FDA grades available.

Quality and compliance are a top priority

In today’s pharmaceutical and bio-pharmaceutical industries, cleanliness, traceability and compliance with international regulatory standards (e.g. FDA/USP regulations) are essential for risk management. Employing durable, high-performance and precisely engineered sealing solutions is imperative to meeting these goals and preventing process material contamination.

In the pharmaceutical industry batch processing tends to be the norm. This ensures the traceability from the raw material supplier to the patient in theevent of quality issues. It is therefore critical that seals comply with the increasingly stringent material quality and production standards.

To ensure the hygiene and purity of a batch, special attention must be paid to the documentation of the processes. It is therefore important to know the ingredients of the sealing materials, or appropriate confirmation of biocompatibility according to USP Chapter 88 (Class VI) must be available.

Pharmaceutical / Food industry standards, include;
FDA (Food and Drug Standards).
USP Class VI.
3A Sanitary Standard 18-03: Sanitary compounds.
WRAS: Water Regulations Advisory Scheme.
EC 1935-2004/ EC 2023-2006: Food Contact Materials – Health of consumer.

The Pharmaceutical segment includes a diverse range of applications

Pharmaceutical and Bio-Pharmaceutical equipment represents a wide range of applications and operating conditions. Sealing solutions must meet key operational needs with excellent chemical resistance and optimise the performance of a diverse range of media.

Example applications:
Vertical / horizontal agitators.
Centrifugal pumps.
Volumetric pumps.
Tablet processing machines.
Valves, Pumps, Gear Boxes.

Encapsulated O-Rings

Also known as FEPs and PFAs, these seals are recommended when a standard O-ring has inadequate chemical resistance for an application, and a solid PTFE O-Ring does not have the elasticity for reliable, long term fluid sealing. FEP/PFA Encapsulated ‘O’ rings offer far superior performance to solid PTFE O-rings that routinely suffer from ‘Compression Set’and‘Coldflow’.

Benefits of Encapsulated O-rings and seals:
Exceptional resistance to aggressive chemicals and gas permeability
Cost efficient alternative to Kalrez® and similar Perfluoroelastomer O-ring
Low coefficient of friction allowing reduced wear of equipment
Adaptive sealing force of an elastomeric O-ring
Resistant to compression set/cold flow issues of solid O-rings

Encapsulated O-rings have either a Viton® or Silicone Core, and can be hollow or solid.

Mechanical seals

The chemical and pharmaceutical industry has traditionally been very difficult to seal. Most liquids and mediums that require sealing are very corrosive and the seals themselves are used in very arduous situations.

Mechanical seals for the pharmaceutical sector are designed to avoid the formation of deposits that could cause bacterial contamination of the medium (medicinal). These mechanical seals are also able to operate in totally dry conditions, with both abrasive and non-abrasive media. They also ensure the typical flexibility requirements in terms of axial and radial run-out of the agitator shafts are fully met. Materials used for the mechanical seals for the Pharmaceutical applications are strictly Food-Grade.

Benefits of mechanical seals:
Long life
Great reliability
Hygienic design
Dry running possibility
Seal faces not in contact with medium
Double seals with buffer sealing water

Typical Pharmaceutical applications include; water pumps, gas pumps, process engineering plant, steam pumps and dosing pumps.

UK Seals supply dependable, compliant seals that meet key operational needs with excellent chemical resistance and remarkably long service life. We recognise the demands of the Pharmaceutical industry are constantly changing and as a responsible supplier, we offer materials to comply with the regulations and requirements including FDA and EU Legislation.

We offer a full range of FEP Encapsulated O-rings and Mechanical Seals, fully compliant to all requirements stipulated on FDA and EC Regulation, on materials and articles intended to come into contact with products manufactured for the Pharmaceutical industry.

Contact UK Seals’ Technical team to discuss the best sealing solution for your process. Call us on +44 (0)1388 722817 or send us an email to