Parameters / Specifications Model: 167DA‑85 Series: Fisher 167D Series (Switching Valves) Type: Three-way switching valve (ports A, B, C plus control/vent port D) Body Size & End Connections: Ports A and C: ¼ or ½ inch NPT; Vent and control (Port D) & Port B: ¼ inch NPT Maximum Inlet Pressure (Body Rating): 125 psig (≈8.6 bar) standard; some versions up to 400 psig depending on construction Set Pressure (Spring Range) Options: Typically 0–125 psig Temperature Capabilities (depending on materials): Nitrile (NBR) standard service: –20 °F to +180 °F (≈ –29 °C to +82 °C) Low temperature service: –40 °F to +180 °F (≈ –40 °C to +82 °C) Fluoroelastomer (FKM) high-temperature service: 0 °F to +300 °F (≈ –18 °C to +149 °C) Approximate Weight: ~1.2 lb (≈0.5 kg) for standard aluminum body Flow / Sizing Coefficients: Wide-open flow coefficient (Cv) for ¼ NPT size around 30.58; ½ NPT around 32.22 Construction Materials: Standard aluminum body and spring case; optional stainless steel available; diaphragm, valve stem, and plug materials vary Media: Gaseous fluids (air or compatible gas) suitable for pilot-instrumentation, switching, venting, etc. Applications: Switching of pneumatic circuits—when control pressure falls below or rises above a setpoint, it opens one port and closes another (typical fail-safe or lock-up arrangement)
