Burkert Valves > How to select the correct Burkert valve for your application.
Burkert have released their new selection guide and chemical resistance chart. Burkert know that choosing the correct valves inside any process control system is vital to guaranteeing the reliability and performance of that system.
A Burkert valve that would be used in a brewery would be very different to a valve that would be found in a pharmaceutical application.
During normal use a standard Burkert solenoid valve, most of the internal parts such as plunger, return spring and seals are open to the media. As a result, facts about temperature, pressure and the chemical compounds are vital to be able to make an educated material selection.
In the event the production process includes liquid foods, the elastomers and plastics will need to meet hygiene and food regulations. Also a few processes need to have a cleaning cycle carried out in between production processes. Information is therefore needed to make sure that there is no unnecessary material degradation.
Aspects, for example higher temperatures, chemical concentrations and mechanical loading, all affect the efficiency of each component that may be made of a variety of materials. Standard Burkert valve bodies are manufactured from stainless steel, Polyamide or brass. To pick the type of valve hat will be suitable for you application will depend on several factors, however normally a Burkert plunger type direct acting will be ideal for clean and neutral fluids. Whereas, pivoted armature valves will give you reliability by using media separating membrane to control, contaminated, aggressive or corrosive fluids.
The larger Burkert range:
There is a large range of options for separating and sealing membranes with every one possessing advantages and disadvantages. The mixture of cost, pressure, temperature and chemical compounds, all having an impact on this design decision. Listed below are some of the common substances in use with short information of their properties.
Polytetrafluoroethylene is virtually insoluble and chemically inert. Polytetrafluoroethylene is resistant to high temperatures and Polytetrafluoroethylene ball valve seats, as they are naturally lubricated the do not need any extra lubrication. Polytetrafluoroethylene flange gaskets and diaphragms are utilized in extremely severe chemical resistance applications.
Ethylene Propylene Terpolymer is used for most valves as it is a synthetic rubber. It is cheap and has an extremely high tolerance to temperatures up to 90⁰c, acids, salts and alkalis. Yet it is not to be used with concentrated acids, oils and petrochemicals oils.
Nitrile rubber is extremely resistant to petroleum and oil, but is weak on oxidising materials such as acids. Nitrile is extremely resistant to abrasion and is far cheaper that perfluoro- elastomers and Fluorinated elastomer.
Fluorinated elastomer and perfluoro- elastomers cost more than nitrile and neoprene elastomers due to the fact that they give you extra chemical resistance and higher temperatures .Some types of perfluoro- elastomers can work frequently at temperatures higher than 200 ⁰ c.
Polyphenyl Sulphide is a high end thermoplastic that is used in lots of engineering applications. That can perform above 200⁰c; it is also resistant to alkalis, acids and abrasion. Polyphenyl Sulphide can be chosen as a valve body material.
Polyvinylidene fluoride is resistance to acids, bases and solvents, therefore it is the perfect valve body material in lower temperature atmosphere. It is also very flexible and could be welded, injected and moulded, therefore making it simpler in the manufacture of valve bodies.
Polyether ether ketone has fantastic chemical and mechanical qualities however is vulnerable to large concentrations of nitric and sulphuric acid. As the performance is much better this means that it is more expensive, but provides superior qualities for valve bodies.
For help selecting the right Burkert valve for you application or information on the complete range of Burkert products, contact us today.