RD Dry-Running Mechanical Seal Update

In our original post about our dry-running RD seal we mentioned that the next generation would be fully ASME BPE compliant as a standard, unlike seals from other manufacturers: http://sharpemixers.blogspot.com/2009/07/next-generation-dry-running-mechanical.html. We introduced new grades of elastomers for specific use in high end biopharm applications. These elastomers meet or exceed the requirements of USP grade materials. The seal elastomers have the following properties:

• Available in EPDM (standard), FPM (Viton®^a equivalent⁾, Silicone, & FFPM (Kalrez®^a equivalent⁾.



• Full traceability



• Properly postcured



• Contain no ingredients derived from animals



• Free from melamine and mercury



• Complies with the FDA Code of Federal Regulations for rubber and rubber-like materials under Title 21, Paragraph 177.2600.



• Complies with the 3-A Sanitary Standards for rubber and rubber-like materials used as product contact surfaces in dairy equipment, number 18-03, Class II.



• Compound has passed testing in accordance with the current USP section <87> and <88> Class VI – 121°C or ISO/AAMI/ANSI 10993-5, 6, 10 and 11.

The seal has gone through some design changes as well to better meet the requirements of BPE:

· The ID of the debris well is tapered for drainability.

· The debris well flush ports are angled for drainability.

· Debris well gasket has been replaced by an o-ring which mounts close to the flange hole.

· Heat number for wetted metal parts are etched on the parts.

· Silicone Carbide (standard) and Tungsten Carbide static faces are available, as well as Hastelloy® ^b C-276 & AL-6XN®^c metal parts.

· Various finishes, including electropolish & passivation are available.

a - Viton® & Kalrez® are the registered trademarks of DuPont Performance Elastomers.

b - Hastelloy® is a registered trademark of Haynes International, Inc.

c - AL-6XN® is a registered trademark of Allegheny Ludlum Corp.

Next generation dry-running mechanical seals

Sharpe Mixers has partnered with Roplan AB of Sweden, a leading supplier of sanitary and industrial mechanical seals, to develop our RD line of dry-running mechanical seals. The Sharpe Mixers Dry Running RD Mixer Seal has been designed specifically for use in mixers, agitators and reactors where possible product contamination from barrier fluids is not allowed. The design is capable of handling 0.15” total run-out. A proprietary Carbon blend virtually eliminates the face squeal that is common with other seal brands. The seal is available with a plain mounting flange or with a debris well.

The first generation of the seal was similar to existing products in the market such as Flowserve’s VRA or John Crane’s Type 32 mechanical seals. We are now releasing the next generation of this product which surpasses anything currently in the market in its adherence to ASME’s Bioprocessing Equipment (BPE) standard. Both Sharpe Mixers and Roplan are working with the BPE committees on seal design. The design has been updated to enhance cleanability. Internal surfaces have been sloped to facilitate drainage, including the debris well flush ports. All non-metal wetted components are either FDA approved or USP Class VI rated, standard. Internal metal surfaces have been polished to a minimum 20 Ra finish, standard. For the same cost as another supplier’s basic, non-pharmaceutical seal you could have a fully BPE compliant seal!

The seal comes as a cartridge assembly (see image below) for easy installation and the proper running height is pre-set with the cartridge clips. No more measuring! Just bolt the seal plate down, slide the shaft through, and tighten the setscrews. Wetted metal parts are etched with a heat number which is traceable to a mill test report to verify proper alloy to help simplify your system validation.

Seals can be made with special materials as well to accommodate your needs. If you want the most BPE compliant dry-running mixer seal on the market, come to Sharpe Mixers.

Materials of Construction

Rotary Seal: FDA approved Carbon

Stationary Seal: FDA approved Silicone Carbide
Metal Components: 316L Stainless Steel

Elastomers: USP Class VI FPM or EPDM Standard

Performance Capability

Temperature: Up to 300F (149C)

Pressure: Full vacuum to 200PSI (13.8 bar)

Speed: Up to 350 RPM

Sizes: 5/8” – 3”