Corrosion-proof automated valves

When handling flows of corrosive liquids, safety is important and often the external environment is also corrosive. Valves with automation must therefore also be adapted to cope with a corrosive external environment. Lyma explains!

When handling corrosive and abrasive liquids, there is one factor that is of paramount importance: safety. Many chemicals can be flammable, toxic, corrosive and must not, under any circumstances, come into contact with people or other matter. Often the external environment is also corrosive. To reduce the risk of leaks and accidents, it is therefore important to be extra careful when choosing the right materials for the products that will handle the liquid and also to take the external circumstances into account.

Corrosion-proof your valves with the right materials

Using the right material for the right media is not only important for the safety of your process, but also for its durability. By choosing a durable material with high resistance to the fluid, you increase the lifetime of both your equipment and your process while reducing the risk of unexpected failures or stoppages. Scheduled maintenance stops instead of unscheduled maintenance stops improve operational economy. It is also important to consider good external corrosion protection for valves, pneumatic actuators and accessories to ensure a durable and safe solution.

Plastic is always preferable

When it comes to handling corrosive fluids and media in various types of pumps, valves and pipework, plastic is preferable to metallic solutions. Thanks to its good material properties, plastic is superior to most types of metals in corrosive applications and in most cases a more cost-effective material compared to metals. Most common plastic materials for valves are PP, PVDF, U-PVC or C-PVC. The actual fluid, fluid concentration, temperature and operating pressure must be considered when selecting the plastic grade. Valves are usually operated manually or by means of a pneumatic actuator.

Corrosion-proof actuators for safer operation

Examples of pneumatic actuators

For a durable and safe overall solution, the pneumatic actuator should also be corrosion-proof. An actuator or actuator is simply a "motor" used to operate the valve. Actuators are intended for on/off or control. The design of the actuators is mainly divided into two types, 90° actuators or multi-turn actuators. Pneumatic actuators are available in two versions: double-acting or single-acting actuators. With a double-acting actuator, you need to push air into the actuator to both close and open. With a single-acting actuator, air is only needed in one direction, the other direction is controlled by springs. Pneumatic actuators are also available as multi-turn actuators and are mainly used for control valves.

A solenoid valve is often used to control the air supply during on/off operation. The position of the actuator is indicated by means of inductive or mechanical limit switches. Usually the actuators are made of aluminium with a protective outer coating. There are actuators made of corrosion-resistant glass-fibre reinforced polyamide which are preferred in corrosive external environments instead of aluminium actuators. In addition, accessories such as end position indication and plastic solenoid valves make the whole unit corrosion resistant to both the medium and the external environment.

Lyma can help you make the right choice

At Lyma, we have been working with corrosive liquids for over 40 years. We have extensive experience in material selection and can help you to more easily combine the right material for your liquid.