STERIVALVES GASKET: NOT ONLY AN ACCESSORY

STERIVALVES GASKET: NOT ONLY AN ACCESSORY

In our sector the use of elastomeric gasket  is the solution universally recognized, but each application has its own characteristics and the wrong gasket can undermine the whole process.
 
Sterivalves knows that the choice of material and design plays a key role.
 
The compound which comprises the gasket is of crucial importance and must have at least the following characteristics:

  • It must be sufficiently flexible to adapt to the surfaces.
  • It should not be attacked chemically by the solvents used in the process.
  • It must resist the operating temperature
  • It must resist the washing/sterilization temperature.
  • It must resist the pressure present inside the valve.
  • It must minimize friction to wear down as little as possible.

Depending on the field of use it may be required compliance with FDA, USP class VI (USP 26, NF21, 2003 Class VI) and the European regulation for materials in contact with food (EC) 1935/2004. 

The available elastomers are:

Silicone (VMQ): it is the first choice material in the pharmaceutical field thanks to its resistance to chemical attack, oxidation (oxygen  and ozone even hot) and aging, to the wide range of operating temperature. The silicone gaskets manufactured by SteriValves are in platinum silicone which ensures the highest purity and it is the most suitable for use in the pharmaceutical industry and they are equipped with a declaration of conformity FDA 21CFR 177-2600, upon request declaration of conformity  United States Pharmacopeia (USP) Classe VI is also available. Available colorless,  or other colors on request.

EPDM: it is the material of choice in the food industry  since it is more resistant  than silicone to chemical attacks .Gaskets are supplied with declaration of conformity FDA 21CFR 177-2600. Available white, other colors on request.
 
PTFE coated  EPDM:  the PTFE coating decreases the coefficient of friction of EPDM , improving the smoothness of the product and reducing the torque of the valve. Gaskets are supplied with declaration of conformity FDA 21CFR 177-2600 and FDA 21CFR 177-1520. Available white, other colors on request.
 
Conductive EPDM: it has a conductivity of 10 3 Ω and thus prevents the accumulation of electrostatic charges. Gaskets are supplied with declaration of conformity FDA 21CFR 177-2600. Gaskets are available in black color.

FKM,it is a fluoropolymer that has a degree of resistance to chemical aggression very high and is able to replace the EPDM where this is not compatible with the substances in contact with the gasket, also combining excellent properties at high temperatures, better than silicone and EPDM. Fluoropolymers are resistant to degradation due to exposure to UV rays and ozone. Gaskets are supplied with declaration of conformity FDA 21CFR 177-2600. Available white, other colors on request.
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PTFE coated FKM , combines the FKM mechanical and resistance  characteristics temperature and  those of resistance to the aggression of chemical agents of PTFE. The part of the seal exposed to the product is constituted by a layer of PTFE which rests on a base FKM which gives elasticity to the whole and ensures the tightness of the valve. Gaskets are supplied with declaration of conformity FDA 21CFR 177-2600 and FDA 21CFR 177-1520. Available white, other colors on request.

PTFE: these gaskets have an excellent resistance to chemical agents, high temperature (over 200 C°) and a low coefficient of friction. They can be used in the presence of solvents and harsh chemicals, each time there is the need to avoid the adhesion of the product to the gasket. PTFE gaskets are the most suitable for the most demanding applications because they maintain their characteristics in a wide range of environmental conditions. . Gaskets are supplied with declaration of conformity FDA 21CFR 177-1550. Available white, other colors on request.

The design must allow the gasket to adapt perfectly to ensure tightness to solid and liquid products ensuring a consistent lasting. For valves which are subjected to an intensive use, such as for valves mounted on pneumatic transport or for valves which have to be operated hundreds of thousands of times it may be necessary to use inflatable seals, as in the case of Pharmalite, to minimize  the release of particles in the product.

The gasket is not a simple accessory, it has a critical role that allows the valve to do properly its job ensuring the seal.