Carbon Steel WCB Ball Valve — ANSI 150 Flange, SS304 Ball, PTFE Seat

The WCB ball valve with ANSI 150 flange is the standard isolation component for industrial natural gas, LPG, steam, oil, and general process fluid lines where the mechanical strength of carbon steel is the primary criterion and body corrosion resistance is not required. The WCB body provides greater mechanical strength than cast iron and is compatible with direct welding to ASTM A106 pipes in the field — the standard for Oil & Gas, petrochemical, and industrial process installations in Mexico. The SS304 stainless steel ball and PTFE seats ensure tight, leak-free shutoff and chemical resistance of the fluid-contacting surfaces, while the WCB body keeps the cost significantly below the SS316 equivalent.

WCB vs. SS316 in flanged ball valves — when to choose each

The decision between a WCB body and an SS316 body is the most frequent when specifying ANSI 150 flanged ball valves:

• Specify WCB when: The fluid is natural gas, LPG, steam, oil, process oils, condensates, or process water without high chlorides. The WCB body does not contact the fluid in the open position — the SS304 ball and PTFE seats are the only exposed surfaces. For these fluids, the WCB body is sufficient and more economical.
• Specify SS316 when: The fluid is seawater, solutions with high chlorides, dilute acids, or fluids where external body corrosion (due to environment or flange leaks) is a real risk. The SS316 body resists both external and internal corrosion.

Construction materials

• Body: Two-piece WCB carbon steel (ASTM A216 Gr. WCB) — high mechanical strength, excellent weldability with ASTM A106 pipes, significantly lower cost than SS316 in large diameters
• Ball: SS304 stainless steel with mirror-polished finish, full port — the only metal component in direct contact with the fluid in the open position
• Stem: SS304 stainless steel with PTFE packing
• Seats: Virgin PTFE — tight, leak-free shutoff in both directions. PTFE covers the chemical compatibility of most fluids that WCB handles: gas, steam, oil, and process water without high chlorides
• Connection: ANSI 150 raised face (RF) flanges, ASME B16.5 drilling
• Handle: Carbon steel or stainless steel depending on model
• Actuator mount: Integrated ISO 5211

Technical specifications

• Type: Floating quarter-turn ball, full port
• Body design: Two-piece body
• Body material: WCB (ASTM A216 Gr. WCB)
• Ball: Polished SS304, full port
• Stem: SS304
• Seats: Virgin PTFE — tight, leak-free shutoff in both directions
• Stem packing: PTFE
• Connection: ANSI 150 RF flanges — face-to-face ASME B16.10
• Flange drilling: ASME B16.5
• Nominal pressure: ANSI 150 — up to 19.6 bar (285 psi) at ambient temperature
• Operating temperature: -20 °C to +150 °C with standard PTFE seat
• Actuator mount: ISO 5211 — compatible with quarter-turn pneumatic and electric actuators
• Recommended flange gasket: Spiral-wound WCB + graphite for steam and high temperature; virgin PTFE for aqueous fluids and gases at moderate temperature

Fluid compatibility

• ✅ Natural gas, LPG, and dry industrial gases
• ✅ Crude oil, process oils, and hydrocarbon condensates
• ✅ Low and medium pressure steam up to 10 bar with graphite packing
• ✅ Industrial process water without high chlorides
• ✅ Mineral oils, hydraulic oils, and lubricants
• ✅ Boiler water and steam condensates
• ✅ Compressed air and pressurized industrial gases
• ⚠️ Water with chlorides >200 ppm: risk of corrosion in WCB body — prefer SS316 body
• ⚠️ Acidic or alkaline fluids: WCB body would corrode — use SS316 body or PFA anticorrosive lining
• ❌ Seawater, dilute acids, alkalis: use SS316 ANSI 150 ball valve →

Automation — ISO 5211 for pneumatic or electric actuator

The integrated ISO 5211 mount allows direct mounting of quarter-turn actuators without adapters. For gas and steam services where automatic shutdown upon control system failure is a safety requirement, the single-acting normally closed (NC) pneumatic actuator is the standard configuration — the mechanical spring ensures shutoff without reliance on active electronic components.

• Single-acting NC or double-acting pneumatic actuator: First choice when compressed air supply is available. See ball valve assemblies with pneumatic actuator →
• ON/OFF or modulating electric actuator: For installations without compressed air supply or with Modbus integration to SCADA. See ball valve assemblies with electric actuator →

Main industries and applications

• Oil & Gas — production and transportation: Isolation of crude oil, natural gas, and LPG lines in production facilities, collection manifolds, and transfer lines. The ANSI 150 flange integrates directly into existing installations without modifying piping infrastructure.
• Natural gas and LPG — industrial distribution: Isolation valves in natural gas distribution networks and regulating and metering stations (ERM). The WCB body with SS304 ball and PTFE seat is the standard specification for these installations in Mexico.
• Power generation — steam and process fluids: Isolation of low and medium pressure steam lines, boiler water, and process fluids in generation, cogeneration, and combined cycle plants. WCB supports the pressure and temperature range of standard process steam.
• Refining and petrochemical: Isolation of liquid hydrocarbon lines, process gases, and utility fluids in refineries and petrochemical plants where piping classes specify WCB ANSI 150 as the standard material and rating for these services.
• Water treatment — process reagents: Isolation of non-corrosive reagent dosing lines, process water distribution, and general plant services where WCB is sufficient and the cost of SS316 is not justified.
• Manufacturing industry — plant services: Control of heating steam, process water, thermal oil, and compressed air in general manufacturing facilities. WCB with ANSI 150 covers the most frequent service pressures in Mexican production plants.
• Mining: Isolation of process water lines, non-corrosive flotation reagents, and plant services in mining facilities. The WCB body offers the mechanical strength necessary for operating conditions in these plants.
• Pulp and paper: Isolation of steam lines, process water, and non-corrosive fluids in paper processing plants. For corrosive process fluids such as black liquor, sulfuric acid, or sodium chloride, specify SS316 body or special materials.

For the full range of flanged WCB ball valves, see carbon steel ball valves category →

Data Sheet