Ball Valves for Geothermal Power Plants
Duplex 2205 wellhead isolation ball valves, NACE MR0175 gate valves for H₂S-containing geothermal brine, and IBR-certified steam valves for geothermal power generation.
Which ball valves are used for geothermal power plants?
Geothermal power plants extract steam and brine from underground reservoirs at temperatures up to 350°C and pressures up to 100 bar, often containing high concentrations of hydrogen sulphide (H₂S), carbon dioxide, and dissolved solids including silica scale and chlorides. This combination of sour gas, high temperature, scaling fluids, and two-phase flow (steam + liquid) demands specialised valve materials and designs not typically found in conventional power or oil & gas applications. Vajra Industrial Solutions supplies Duplex 2205 and SS316L valves for wellhead and brine service with NACE MR0175 compliance, and IBR-certified gate valves for the steam turbine supply headers.
Ball Valve (Duplex 2205)
Wellhead isolation and Christmas tree - sour brine (H₂S + CO₂ + Cl⁻) at 200–300°C; fire-safe, anti-static
Critical Requirements
- H₂S service - NACE MR0175 / ISO 15156 mandatory for all wetted metallic components; HRC ≤ 22 Rockwell hardness limit on body, trim, and fasteners
- Silica scaling - full-bore valves only; no throttle positions; pipeline injection of scale inhibitor upstream of brine valves
- Two-phase flow (steam + liquid brine) - metal-to-metal seat or reinforced PTFE; no soft-seat-only designs in wellhead service
- IBR certification for steam turbine supply headers in India - Form III-C material and Form III-E hydraulic test certificates mandatory
- Chloride stress corrosion - Duplex 2205 or SS316L (not SS304); super duplex 2507 for high-chloride (>5,000 ppm Cl⁻) fields
- Geothermal flash steam often contains non-condensable gases (NCG: H₂S, CO₂, NH₃) - valve materials must resist corrosion in this mixture
Service Challenges
- Geothermal brine - complex mixture: H₂S (1–10,000 ppm), CO₂ (1–20%), Cl⁻ (1,000–100,000 ppm), silica (200–1,000 ppm), temperature 100–350°C
- H₂S sour gas - sulfide stress cracking (SSC) in high-strength steels; NACE MR0175 hardness limits mandatory
- Silica scale - deposits at pH > 7 or on cooling; full-bore valves and scale inhibitor required
- Geothermal steam with H₂S + CO₂ - more corrosive than clean steam; SS316 or Duplex 2205 trim mandatory
- Chloride-rich brine (some volcanic fields) - pitting and crevice corrosion; Super Duplex 2507 or titanium for highest chloride fields
Vajra Ball Valves
High-performance ball valves for reliable shut-off and control in various industrial applications.
See the full Ball Valves rangeOther valves for geothermal power plants
Ball Valves for other applications
Connected Engineering
Need ball valves for geothermal power plants?
Send your line list or datasheet — we supply ball valves for geothermal power plants to the right material, class and standard with full certification and a 24-hour quote.