All KE-ARM ball valves (straight and three-way) are also manufactured
of duplex stainless steel.
Duplex steel grades consists of two metallurgical structure phases, austenite
and ferrite. These materials provide better corrosion resistance, particularly
chloride stress corrosion and chloride pitting corrosion, and higher strength
than standard austenitic stainless steels.
Predictive measurement of a stainless steel's resistance to localized
pitting corrosion based on its chemical composition is called
PREN (Pitting resistance equivalent number). In general: the
higher PREN-value, the more resistant is the stainless steel to localized
pitting corrosion by chloride. Additionally, crevice corrosion is also
a significant factor for choosing the right material and a PREN > 40 is
typically specified for seawater service.
Application of duplex ball valves
reverse osmosis (RO)
brackish water reverse osmosis (BWRO)
seawater reverse osmosis (SWRO)
Offshore oil and gas industry
Pulp and paper industry
Saliferous fluids, hydroxide
Connection to piping
internal thread (KM 9101.X) – G (BSPP), NPT, R (BSPT), Rp