All slurry service valves will eventually wear out!Slurries can be highly abrasive,thick,and filled with solids,wreaking havoc on any pump and valve it comes into contact with.So what can you do to keep valve maintenance costs and downtime to a minimum?Unfortunately,there's no simple answer to this question;slurries are simply hard on equipment.But there are certain features you can look for in a slurry service valve that are considered "ideal" when regulating slurries.
REPLACEABLE VALVE SEATS
Valve seats take the brunt of slurries because their job is to protect the metal components of the valve and prevent leaks.As valve seats wear out,the valve cannot do its job and shut off the fluid completely.It is recommended that slurry service valves consist of replaceable seat technology to minimize downtime and maintenance costs as the seats eventually wear out and need replacing.
When looking at materials for valve seats,natural rubber tends to hold up the best against abrasive slurries.
FULL PIPELINE OPENING
When the valve is open,it must provide a full pipeline opening.
The positive shut-off feature reduces any downstream leaks by providing a positive closure to prevent flow within a piping system.This feature is especially important when regulating slurries because slurries can be harmful to humans and the environment.
COMPONENTS AVAILABLE IN CORROSION & WEAR RESISTANT MATERIALS
Slurries are known to be highly corrosive and abrasive,so the valve must have several material options that are resistant to corrosion and abrasion.
Components coated with a hardfacing material,such as Stellite,are great options against the rough nature of slurries.Stellite is made of cobalt-chromium alloys,which have high wear resistance properties.
HIGH PRESSURE & TEMPERATURE RATINGS
The pressure and temperature of slurries dictate which elastomers and materials of construction the valve should consist of.Not all materials are rated for elevated temperatures and pressures,so it's important to understand thecharacteristics of the slurryto select the appropriate materials of construction and components.
This feature is an operator's dream!A self-draining (or purging) valve reduces maintenance downtime and costs.
Please understand that no one valve meets all of the above requirements.The engineer must decide which features are most important based on thecharacteristics of the slurry to minimize maintenance downtime and costs.