{{unreferenced, date=August 2009
Pneumatic non-return valves are used where a normal
non-return valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction.
Check valves are two-port valves, meaning they have t ...
would be ineffective. This is for example where there is a risk of
flood water entering a site but an equal risk of pollution or a
chemical spills A chemical accident is the unintentional release of one or more chemical hazard substances which could harm human health and the environment. Such events include fires, explosions, leakages or release of toxic or hazardous materials that can cause ...
leaving a site and polluting the environment.
Pneumatic non-return valves are installed below ground and can be used to pneumatically lock the non-return valve closed thus containing a site in the event of a spill.
It is common practice to lock sites using pneumatic non-return valves during the loading or transferring of chemicals or hazardous waste. Pneumatic non-return valves have a longer service life when compared to
pneumatic bladder
A pneumatic bladder is an inflatable (pneumatic) bag technology with many applications.
Emergency management applications
Pneumatic bladders are used to seal drains and ducts to contain chemical spills or gases. Pneumatic bladders are often used f ...
systems.
Valves
Environmental protection