Delivering Fluid Sealing Solutions Since 1972

Mixers and Agitators Seals

Mixers and Agitators Seals – Challenges & Solutions

Mixers and Agitators Seals are used in the Food and Drink industry as well as the Pharmaceutical industry. However, Machine Builders and Operators of Mixers and Agitators routinely face special sealing challenges. Below are the top 5 challenges for Mixers and Agitators followed by our fluid sealing solution. M Barnwell Services offer sealing solutions for all mixers and agitators as well as short lead times and guidance on material selection. Contact the team today for more information.

1. Hygienic manufacturing and cleaning process

The hygienic production of the various products in the food and drink industry requires special attention when choosing a sealing solution. Previously, mixing shafts were sealed with Stuffing box packing. However, this solution is unsuitable from a hygienic point of view. A suitable sealing solution must comply with hygienic design. A component in hygienic design is designed to be cleanable and excludes microbial and particulate contamination of the end product in a hygiene-critical production environment. Therefore, it is crucial that hygienic seals are designed to be free of dead space.

During the cleaning cycle and production cycle, the media must be safely sealed. The cleaning processes are achieved by CIP (Clean-In-Place) and SIP (Sterilization-In-Place). The CIP process is a cleaning method in which individual fully automated processes run according to strictly specified parameters. Cleaning temperatures depend on the application and are approximately 90°C. Active microorganisms are then killed through the SIP Process, which is achieved through sterilization at approximately 140°C using hot water or steam depending on the application. The use of chemical disinfectants is also possible during this process. Sealing solutions must therefore be particularly temperature-resistant, resilient, and have excellent chemical media resistance.

2. Abrasive Media

Abrasive Media also present special challenges for sealing solutions in the Food and Drink industry. These can be crystalline structures such as sugars, powders, grains along with a host of other organic and inorganic materials for the final product.

3. Vacuum Mixing

Starting media are commonly mixed under high pressure and vacuum in the Food, Pharmaceutical and Cosmetic industries. The stages of the process can take place successively or simultaneously in a closed system. Therefore, the materials of the sealing solutions must be able to withstand high pressures and extreme vacuum processes in addition to all other requirements.

4. Contamination

In the Food and Drink industry, choosing a suitable sealing solution can prevent the negative effects on the production of products. Such an example is cross contamination, which can render entire batches of products unusable.

5. Requirements and Certificates

Suitable sealing solutions should meet all required certifications for the Food and Drink and Pharmaceutical industries. This allows machine builders and operators to be sure that the equipment used complies with all regulations and requirements.

Mixers and Agitators Seals solution?

At M Barnwell Services we stock the PS-SEAL®, the perfect Mixer and Agitator seal. The PS-SEAL® product family stands for reliable sealing of rotating shafts at high circumferential speeds, high pressures, and extreme temperatures.


  • Useable under high pressure and in extreme vacuum
  • Very suitable for high circumferential speed
  • Temperature resistant from -90°C up to +260°C Excellent chemical resistance
  • Useable in food and pharma applications due to FDA conformity, EC 1935/2004, and USP Class VI
  • SIP/CIP compatible
  • Good dry running capability
  • Wear resistant and low friction


M Barnwell Services also stock a variety of Garlock products including their range of Compression / Gland Packing and GYLON® Bio-Line Gaskets.

Tanker Lid Seals

For applications involving a lid, or hatch (Main / Butterworth / Inspection), the range of Tanker Seals will be a solution. Only using the highest grade of pure materials means we can offer a low compression set and tolerances to ISO3302-1. For more information click here.

Tanker Seals

If you would like more information about our range or services, visit the Seal Maker Page or contact a member of the team. E & OE.