Pilot-operated hydraulic control valves solve different water-system problems by changing the pilot circuit—not by treating one valve body as a universal function.
Compare YONGFAN 100X Remote Float, 200X Pressure Reducing, 300X Slow-Closing Check, 400X Flow Control, 500X Relief/Sustaining, 600X Electric, 700X Pump Control, 800X DP Bypass, and 900X Emergency Shut-Off valves (Diaphragm ≤DN450, Piston ≥DN500, PN1.0/1.6/2.5 MPa, 0–80 °C water).
300X provides slow-closing backflow prevention; 700X coordinates full start/stop timing electrically with pump motors to prevent surges.
Forcing a single 200X valve to absorb high-rise pressure drops exceeding 4:1 ratios causes violent cavitation, noise, and seat erosion.
Omitting regular inspection of the small pilot strainer allows pipe scale to clog needle valves, freezing the main valve in open or shut position.
Maintenance teams ordering diaphragm rebuild kits for DN500+ valves that use internal piston cylinder architecture.
Controls water level at tank inlets automatically. A remote float pilot in the tank vents or pressurizes the main control chamber to open or close the main valve as water levels rise and fall without external electrical wiring.
Regulates fluctuating high upstream pressure down to a steady, preset downstream pressure. The adjustable pilot continuously senses outlet pressure, throttling the main valve to maintain precise pressure regardless of flow demand.
Combines backflow prevention with controlled, cushioned closing at pump shutdown. The pilot circuit controls the rate of control chamber filling so the main valve closes smoothly without slamming or creating destructive pressure transients.
Limits maximum flow to a calibrated setpoint using a differential-pressure sensing orifice pilot. As network pressure rises, the main valve modulates toward closed to prevent branch overflow in large distribution systems.
In relief duty, opens quickly when upstream pressure exceeds setpoint to discharge excess pressure; in sustaining duty, throttles to guarantee minimum upstream pressure before allowing water flow downstream.
Adds an external electrical solenoid pilot to the hydraulic main valve platform. Allows large-diameter valves to be opened, closed, or staged from remote BMS/PLC electrical commands using pipeline water pressure for stroke power.
Interlocks opening and closing sequences directly with pump motor start/stop circuits. Opens slowly after the pump starts against closed head and closes slowly before motor de-energization to prevent hydraulic shockwaves.
Senses supply-to-return differential pressure across central HVAC headers. As 2-way terminal valves close and system ΔP rises, 800X opens a bypass path to protect chillers and pumps from minimum flow starvation.
Engineered for fire-protection water mains (referenced to GB 25201 framework). Senses downstream pressure drops from opened hydrants or sprinkler release, opening immediately to prioritize fire-water flow over domestic branches.
| Model | Controlled Function | Standard Energy Source | Typical System Location | First Data to Confirm |
|---|---|---|---|---|
| 100X | Tank water level | Water pressure + remote float | Tank inlet header | Tank depth, fill flow, inlet pressure |
| 200X | Downstream pressure | Water pressure + PRV pilot | Riser / pressure zone | Inlet & required outlet pressure, flow |
| 300X | Slow-closing check | Water pressure + pilot timing | Pump discharge header | Pump flow, static head, closing timing |
| 400X | Flow rate limitation | Differential pressure & orifice pilot | Large distribution branch | Required flow limit & available ΔP |
| 500X | Relief / sustaining pressure | Spring-loaded pilot + water pressure | Main / bypass header | Relief or sustaining pressure setpoints |
| 600X | Remote electric control | External electric pilot + hydraulic main | Automated main isolation | Supply voltage, signal & fail position |
| 700X | Pump start/stop coordination | Water pressure + motor interlock timing | Pump discharge header | Pump motor sequence & head curve |
| 800X | Differential-pressure bypass | Pressure difference across sensing ports | HVAC chiller bypass | ΔP setpoint & maximum bypass flow |
| 900X | Pressure-triggered emergency | Hydraulic pressure-drop pilot | Fire-water supply main | Normal/trigger sequence & fire approvals |
Select 100X (Level), 200X (PRV), 300X (Check), 500X (Relief), 700X (Pump), 800X (Bypass).
Nominal diameter (DN50–DN1200+), flange standard (GB/DIN/ANSI), and PN1.0/1.6/2.5 MPa.
Normal, minimum, and peak flow rates (m³/h) and inlet/outlet pressure ranges.
Target downstream pressure, relief pressure, pump electrical interlock, or ΔP setpoint.
YONGFAN hydraulic engineers will verify velocity limits, calculate cavitation indices for 200X, size slow-close timing for 300X/700X, and provide full submittal drawings.
Ductile-iron bodies undergo 1.5× nominal pressure shell verification per EN 12266-1, API 598, and GB/T 13927.
Resilient valve seats and pilot control chambers are pressurized to 1.1× nominal pressure to certify zero drop-through.
Pilots are calibrated on test loops: 100X float levels, 200X pressure stability, 300X closing time, and 800X ΔP response.
Internal and external surfaces receive electrostatic fusion-bonded epoxy powder coating tested for thickness and pinholes.
| Size Band | Construction | Documented Lead Time | Packaging / Logistics |
|---|---|---|---|
| DN50 – DN200 | Diaphragm Type | 15 – 25 Working Days | Export Wooden Crating |
| DN250 – DN500 | Diaphragm / Piston | 30 – 45 Working Days | Heavy-Duty Sea Crates |
| DN600 – DN1200 | Piston Type | 45 – 70 Working Days | Custom Structural Palletizing |
| DN1400+ | Heavy Piston | Confirm by Project RFQ | Staged Project Shipping |
Most variants do not. The 100X, 200X, 300X, 400X, 500X, 700X, 800X, and 900X use line water pressure for operation. The 600X uses external electric solenoid control.
YONGFAN uses DN50–DN450 diaphragm construction and DN500 and above piston construction for the shared hydraulic control platform.
The shared platform is documented in PN 1.0 MPa, PN 1.6 MPa, and PN 2.5 MPa pressure grades.
The published standard operating range is 0 to 80 °C for water. Applications above 80 °C require specialized trim and sealing review.
300X is a hydraulic slow-closing check valve for backflow surge prevention. 700X coordinates opening and closing sequences electrically with pump motor start/stop.
400X regulates branch flow rate. 800X regulates a bypass loop based on differential pressure between supply and return headers.
No. DRV, KPF, and BYF balance branch resistance. 800X is a pilot-operated bypass valve that maintains system-level ΔP across central chiller headers.
Yes. The pilot tubing and pilot valves can be isolated via small shutoff cocks and serviced while the main valve body remains bolted in the pipeline.
Do not purchase 100X–900X valves solely for manual shut-off; use standard gate, ball, or butterfly valves for basic isolation.
FCU and AHU coil control requires motorized control valves. 100X–900X valves are engineered for large plant and distribution mains.
800X regulates header bypass; it does not balance individual hydronic coils. Specify DRV/BYF balancing valves on branch circuits.
Verify project-specific fire authority approvals (CCCF, UL/FM, GB 25201) before approving 900X emergency fire-water valves.
Send your pipeline DN, required hydraulic function (level, pressure, surge check, pump control, or bypass), design flow rates, and operating pressures. YONGFAN application engineers will verify sizing, calculate pilot settings, and supply complete submittal drawings.
