A motorized valve is not selected by pipe size alone. Control mode, differential pressure, fail position, actuator voltage and valve characteristic determine whether the water loop will actually regulate as intended.
Compare YONGFAN FCU 2-way replacement valves (DN15–DN25, Johnson/Siemens/Honeywell footprints), 3-wire on/off ball valves, 2-wire fail-in-place ball valves, EDV dynamic balancing 2-way valves (DN20/DN25, 4 bar close-off), KYQ modulating motorized ball valves (DN32–DN100, AC 24 V, spring return), and VG3000 proportional globe valves.
Operating a standard 3-wire FCU ball valve (<0.6 MPa limit) in high-head risers allows differential pressure to push the ball off its seat.
Installing an on/off valve on an AHU heating coil causes discharge air to cycle between hot and cold blasts without reaching steady state.
Conventional valves change flow whenever neighboring valves cycle. EDV pressure-independent valves maintain constant flow regardless of ΔP.
Failing to specify spring-return (KYQ / Siemens-type) vs fail-in-place (2-wire ball) leaves coils unprotected against freeze-up on power cuts.
Independently manufactured replacement valves for legacy terminal installations. Johnson-type features split construction (below 94 °C); Siemens-type features spring-return motor drive (AC 220/24/110 V, 2–90 °C, 50% glycol); Honeywell-type features bidirectional flow and auxiliary interlocking switches.
Compact forged brass motorized ball valve using separate open, close, and common conductors. Driven by a synchronous motor (AC 220 V, 4 VA during stroke, 15 s operating time, 1.6 mm stem travel, <0.6 MPa closing pressure, 2–90 °C fluid).
3-wire motorized ball valve with an integrated mechanical override knob for manual positioning during power outages or commissioning. Produces 6 N·m torque, 40–50 s soft stroke time, IP54 enclosure, PN 1.6 MPa, and 5–95 °C fluid rating.
DC motor-driven 2-wire ball valve engineered to hold its last position upon power removal. Generates 10 N·m torque, ~15 s actuation time, ≤0.4 MPa closing pressure, PN16–PN20 rating, and universal AC 100–230 V or DC 9–30 V supply.
Combines motorized on/off control with internal dynamic flow balancing in a single valve body. Sized in DN20/DN25 (PN16, 4 bar closing pressure, 0–95 °C fluid) with an M30×1.5 thermal actuator interface (110 N, 2 VA, IP54).
Large-capacity modulating motorized ball valve for central AHUs and plant loops (DN32–DN100, PN 1.6 MPa, 2–100 °C, IP65). Operates on AC 24 V ±10% with 3-wire floating or 3-wire proportional control and spring-return fail-close behavior.
Linear globe-style PID control valve for high-precision fluid regulation (PN 1.6 MPa, 2–90 °C, chilled water and 50% glycol). Features equal-percentage flow characteristic, brass body, stainless stem, and Kv 0.01% tight seat shut-off.
| Product Family | Main Duty | Key Documented Boundary | First Field to Confirm |
|---|---|---|---|
| FCU 2-Way Replacement Valve | Legacy FCU zone-valve replacement | DN15 / DN20 / DN25; Johnson, Siemens, Honeywell types | Existing valve footprint & actuator voltage |
| 3-Wire Motorized Ball Valve | Fast FCU / small-loop on-off | 15 s stroke · 4 VA · Closing pressure <0.6 MPa | Wiring logic & close-off differential pressure |
| Manual-Override Ball Valve | Serviceable loop isolation / control | 6 N·m · 40–50 s · IP54 · PN 1.6 MPa | Need for manual mechanical override knob |
| 2-Wire Fail-in-Place Ball Valve | Hold last position on power loss | 10 N·m · ~15 s · AC100–230V / DC9–30V | Required power-loss fail state |
| EDV Dynamic Balancing Valve | Pressure-independent terminal flow control | DN20/DN25 · PN16 · 4 bar closing pressure | Design flow & available system ΔP |
| KYQ Modulating Ball Valve | Larger AHU / plant modulating control | DN32–DN100 · AC 24 V · IP65 · Spring return | Control signal & design flow schedule |
| VG3000 Control Valve | Proportional globe-style regulation | PN 1.6 MPa · 2–90 °C · Equal-percentage | Required flow coefficient & valve authority |
Coil water flow (m³/h, L/s) and entering/leaving temperatures (ΔT).
Available branch differential pressure and target valve pressure drop for authority.
On/off (2-wire/3-wire), 3-position floating, or analog (0–10 V / 4–20 mA).
Spring-return fail-close (KYQ) vs Fail-in-place; AC 220 V vs AC 24 V.
YONGFAN application engineers will calculate valve authority (a ≥ 0.5), size Kvs, verify actuator torque, and provide complete submittal datasheets.
Every assembled brass and ductile-iron valve body undergoes 1.5× rated pressure hydrostatic shell testing.
Actuators are matched to valve bodies and cycle-tested 50 times to verify smooth limit-switch cutoff and stem alignment.
KYQ modulating valves undergo full 0–10 V / 4–20 mA stroke verification to ensure linear flow response across 0–100% opening.
EDV dynamic balancing valves are benchmarked across 20–300 kPa differential pressure to verify pressure-independent flow.
For simple terminal on/off control, start with the FCU 2-way replacement valve or the compact 3-wire motorized ball valve.
Three wires describe the electrical power interface (open/close/common). KYQ is the documented family for proportional modulating control.
The 2-Wire Fail-in-Place Motorized Ball Valve holds its last position when electrical power is removed.
The Siemens-type FCU valve and KYQ modulating ball valve are documented with mechanical spring-return fail-close behavior.
Choose EDV when a terminal branch needs motorized on/off control plus dynamic balancing in one valve to absorb network ΔP swings.
KYQ (DN32–DN100 ball) and VG3000 (proportional globe) are engineered for modulating AHU coil temperature control.
Yes. YONGFAN manufactures independent replacement valves matching those footprints. No endorsement by trademark owners is implied.
Design flow, DN, fluid temp, close-off ΔP, control mode (on/off vs mod), actuator voltage (220V/24V), and power-loss fail state.
Standard control valves switch or modulate flow; they do not balance branches unless the EDV pressure-independent model is selected.
Large plant-room mains requiring pressure reduction or surge control belong under the 100X–900X Hydraulic Valves portfolio.
Sizing modulating valves to line size results in oversized Kvs and loss of control authority; size to design flow and available ΔP.
Do not use motorized control valves simply as manual isolation shutoffs; install dedicated ball or butterfly valves for servicing.
Send your coil flow rates, system differential pressures, control signal specifications, and fail-safe requirements. YONGFAN application engineers will verify valve authority, match actuator torque, and provide complete submittal drawings.
