Duplex steel ball valve

Production range

• DN 10 – DN 100, PN 16 – PN 250
• NPS ⅜″ – NPS 4″, Class 150 – Class 1500

Standard materials of duplex steel ball valves

• Duplex 1.4462 (S31803, S32205, F51/F60, 2205, X2CrNiMoN22–5–3) – PREN=35
• Super Duplex 1.4410 (S32750, F53, 2507, X2CrNiMoN25–7–4) – PREN=43
• Super Duplex 1.4501 (S32760, F55, X2CrNiMoCuWN25–7–4) – PREN=41
• 1.4539 (N08904, 904L, X1NiCrMoCu25–20–5) – highly alloyed austenitic stainless steel – PREN=34
• 1.4547 (S31254, F44, 254SMO, X1CrNiMoCuN20–18–7) – super austenitic stainless steel – PREN=44

All KE-ARM ball valves (straight and three-way) are also manufactured of duplex stainless steel.

Material description

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

• Desalination:
  • reverse osmosis (RO)
  • brackish water reverse osmosis (BWRO)
  • seawater reverse osmosis (SWRO)
  • geothermal water
• Offshore oil and gas industry
• Pulp and paper industry
• Chemical industry:
  • Sulphuric acid
  • Nitric acid
  • Saliferous fluids, hydroxide

Connection to piping

• internal thread (KM 9101.X) – G (BSPP), NPT, R (BSPT), Rp
• weld end (KM 9103.X) – butt or socket
• wafer (KM 9107.X) – EN, API, GOST
• flanged (KM 9108.X) – EN, API, GOST