Diaphragm valves for corrosive and demanding industrial processes

When are diaphragm valves used?

Diaphragm valves are particularly suitable in applications where:

• the medium is corrosive or chemically aggressive

• the liquid is viscous or contains particles

• the valve is often manoeuvred

• high density is required in both flow directions

• pressure surges in pipelines should be minimised

The soft closure eliminates pressure surges in the pipework, helping to increase the life of both the valve and its peripherals.

How a diaphragm valve works

A diaphragm valve is constructed with a flexible membrane which is pressed against a lug in the valve body to close the flow.

The design means that:

• the medium is separated from the moving parts of the valve

• spindle and mechanics are protected from corrosion

• sealing achieved at low tightening torques

• the valve is tight in both flow directions

Manoeuvring is done via:

• handwheel (lockable as an option)

• pneumatic actuator

• electric actuator

The valve can be mounted in any position and has a simple and service-friendly design.

Connections and designs

Lyma diaphragm valves can be supplied with several different connection options:

• glued connection

• welded connection

• threaded connection

• flanged connection

The choice of connection depends on the design of the pipework, the pressure class and the characteristics of the medium.

For liquids that diffuse, a diffusion protection to prevent corrosive gases from attacking the valve stem.

Materials and chemical resistance

Diaphragm valves are often used in the handling of:

• acids

• base

• chemicals

• sludge and slurry

• abrasive media

Material selection for valve bodies and diaphragms is crucial for service life and safe operation. Depending on the application, valves can be supplied in plastic, metal or specialised materials with diaphragms adapted for chemical resistance, temperature and pressure.

Lyma helps you choose the right combination of valve body and diaphragm material based on:

• media

• temperature

• pressure

• concentration

• drift cycles

Advantages of diaphragm valves in the process industry

• High tightness and safe shutdown

• Protected mechanical parts

• Suitable for frequent manoeuvring

• Reduces pressure surges in pipework

• Copes with aggressive and contaminated media

This makes diaphragm valves a safe choice in critical industrial processes.

Need help choosing a diaphragm valve?

Contact Lyma we will help you design the right valve for your application - focusing on reliability, chemical resistance and longevity.