316 Stainless Steel Ball Valve — ANSI 150 Flange, Two-Piece, ISO 5211

The SS316 ball valve with ANSI 150 flange is the standard process isolation component for industrial lines from 1" to 6" where simultaneously required: complete bubble-tight shutoff, SS316 corrosion resistance for seawater, moderate chemicals, and industrial processes, and a flanged connection that allows the valve to be removed and replaced in the field without cutting the pipe. Its full bore design ensures that in the open position, the valve does not create any additional restriction to flow — the fluid passes through a smooth cylindrical channel with the same diameter as the pipe.

Construction Materials

• Body: Two-piece in CF8M stainless steel (ASTM A351) — cast equivalent of SS316 with 18% Cr, 8–12% Ni, 2–3% Mo. The main body houses the ball and seats; the side cap is bolted to the body to complete the assembly. Compact design and lower cost than three-piece, suitable for installations where frequent field maintenance of the seats is not a requirement.
• Ball: SS316 stainless steel with mirror-polished finish and full bore — equal to the inner diameter of the pipe. No flow restriction in the open position.
• Seats: Virgin PTFE — two symmetrical seats that embrace the ball on both sides. Bubble-tight shutoff in both flow directions. Practically universal chemical resistance for fluids that SS316 resists.
• Stem Packing: PTFE with stainless steel retainers
• Connection: ANSI 150 raised face (RF) flanges, ASME B16.5 drilling — compatible with stainless steel, carbon steel, PVC, and fiberglass pipes with standard flanges
• Lever: SS316 stainless steel with locking position in open and closed
• Actuator Mounting Pad: Integrated ISO 5211 — compatible with quarter-turn pneumatic and electric actuators from any manufacturer without adapters

Two-Piece Design

The two-piece body is the standard design for flanged ball valves in industrial processes: the main body houses the ball and seats, and a bolted side cap completes the assembly. It is the correct design for process installations where the valve operates continuously without requiring frequent internal access:

• More compact construction: The two-piece body has a smaller outer diameter than the three-piece design of the same nominal diameter — an advantage in installations with limited flange-to-flange space.
• Lower cost: Less material and less machining than the three-piece design — the savings are significant in large diameters (DN100 and above).
• Maintenance: To replace the seats or the ball, the side cap is removed — the valve can be disassembled from the line for bench overhaul. For installations where frequent internal field access without removing the valve is a priority, the three-piece design is more convenient.

Technical Specifications

• Type: Floating quarter-turn ball, full bore
• Body Design: Two-piece body
• Body Material: CF8M (ASTM A351) — cast equivalent SS316
• Ball: Polished SS316, full bore
• Seats: Virgin PTFE — bubble-tight shutoff in both directions
• Stem Packing: PTFE
• Connection: ANSI 150 RF flanges — face-to-face ASME B16.10
• Flange Drilling: ASME B16.5
• Nominal Diameters: 1" (DN25), 1½" (DN40), 2" (DN50), 3" (DN80), 4" (DN100), 6" (DN150), 8" (DN200), 10" (DN250)
• Nominal Pressure: ANSI 150 — up to 19.6 bar (285 psi) at ambient temperature
• Operating Temperature: -29 °C to +200 °C with standard PTFE seat
• Actuator Mounting Pad: ISO 5211
• Recommended Flange Gasket: Virgin PTFE for aqueous and chemical fluids; SS316 spirally wound + graphite for steam and high temperature

Chemical Compatibility of SS316 — Main Fluids

• ✅ Seawater and saline solutions up to 1,000 ppm chlorides at ambient temperature
• ✅ Process water, demineralized water, reverse osmosis water
• ✅ Sulfuric acid H₂SO₄ up to 10% at ambient temperature
• ✅ Hydrochloric acid HCl up to 10%
• ✅ NaOH up to 20%
• ✅ Natural gas, LPG, and dry industrial gases
• ✅ Vegetable oils, light mineral oils
• ✅ Alcohols and low-aggressivity organic solvents
• ✅ Low-pressure steam up to 10 bar with graphite stem packing
• ⚠️ Seawater at elevated temperature (>50 °C) and chlorides >1,000 ppm: risk of pitting in CF8M — consult
• ❌ HF, H₂SO₄ >30%, concentrated ClO₂: use PFA anti-corrosion valve →

Automation — ISO 5211 for Pneumatic or Electric Actuator

The integrated ISO 5211 mounting pad allows direct mounting of a quarter-turn actuator without intermediate adapters. For the flanged SS316 ball valve in DN80 and larger diameters at high process pressures, the operating torque is significant — Cematic sizes the correct actuator with a verified safety factor for each diameter and process pressure.

• Single-acting NC pneumatic actuator: For reagent dosing and services where closure upon failure is the safe state. See ball valve assemblies with pneumatic actuator →
• Electric actuator: For installations without a compressed air network or with integrated Modbus control. See ball valve assemblies with electric actuator →

Main Industries and Applications

• Chemical industry: Isolation of aqueous reagent lines, dilute acids, moderate alkalis, and process solutions. The CF8M body and SS316 ball cover the chemical compatibility of most general chemical industry fluids at standard process pressures.
• Seawater and coastal systems: Desalination plants, seawater cooling systems, port facilities, and marine aquaculture industry. SS316 with molybdenum resists seawater chlorides in continuous service at ambient temperature.
• Industrial reverse osmosis systems: Isolation of membrane modules and pretreatment equipment in medium and large flow reverse osmosis plants. SS316 does not contaminate purified water with metal ions.
• Natural gas and industrial gases: Isolation of gas lines in installations where SS316 is the specified material due to gas aggressiveness (H₂S, wet CO₂) or process cleanliness requirements.
• Food and pharmaceutical industry — utilities: Isolation in purified water distribution systems and auxiliary plant services where flanged SS316 is sufficient without needing the hygienic finish of production areas.
• Power generation: Isolation of treated water lines, cooling water, and process fluids in power generation plants where SS316 is the specified material in process piping classes.

For the complete range of flanged SS316 ball valves, see ANSI flanged ball valves category →

Data Sheet