» Datian · Pump protection
Automatic Recirculation (ARC) Valves
A single valve that protects centrifugal pumps from low-flow damage — sensing flow and recirculating a safe minimum automatically, with no external power, instruments or control system.
What it is
A self-contained valve that keeps a pump out of trouble
The Automatic Recirculation Control (ARC) valve is a self-contained, low-maintenance and reliable device, engineered to protect centrifugal pumps against thermal damage and destruction. Run a pump below its minimum flow and the energy it can’t move turns into heat and cavitation — overheating and instability that permanently damage a pump if it effectively runs dry, especially on hot water at low load.
How it works
The ARC valve guarantees a pre-determined minimum flow through the pump at all times. It is a special form of lift check valve installed downstream of the pump: while process demand is met through the main port, the valve senses flow and diverts a controlled minimum back to source whenever demand drops — so the pump always stays inside its safe operating window. One body replaces a separate recirculation line, control valve, flow meter and check valve to buy, install, wire and maintain.
At a glance
- ✓Precise recirculation control
- ✓Integral check valve
- ✓Self-operating — no power or signal
- ✓Multistage pressure letdown
- ✓Cavitation prevention
- ✓Dampening of pulsations
- ✓Suitable for all fluids
- ✓Low maintenance
One valve, four jobs
What the ARC valve does
Datian’s ARC valve integrates four functions in one body — which is why it replaces a whole recirculation assembly.
Flow sensing
Senses main-line flow and reacts automatically — no instruments, signal or operator needed.
Recirculation control
Opens a bypass to keep a safe minimum flow through the pump whenever demand drops.
Bypass pressure reduction
Multistage decompression takes down the bypass pressure drop while cutting noise and cavitation.
Check valve
A built-in non-return disc stops reverse flow — one body replaces several fittings.
Typical pumps protection
Three ways to protect a pump
Every minimum-flow scheme keeps a pump safe. The difference is how much energy, hardware and maintenance it costs you — and the ARC valve does it in a single body.
Continuous Recirculation System
Minimum-flow requirement for a continuous-circulating pump is unrelated to process-flow discharge changes. Continuous minimum-flow circulation protects the pump well — but it requires greater power output and causes additional energy waste.
Controlled Recirculation System
A control circulatory system is assembled from a check valve, flow gauge and minimum-flow control valve, giving minimum-flow protection when process flow exceeds the pump minimum. The loop closes with no extra energy loss — but it is complex, with higher cost for control components, purchase, installation and maintenance.
Automatic Recirculation Control System
Datian ARCARC valves ensure a pre-determined minimum flow is maintained through the pump at all times, even when the flow rate drops below a certain value. The valve is compact and needs no electrical power — an essential safety feature for modern industrial processes.
↓ ARC BrochureWhy operators choose it
Three reasons it pays off
Reduced energy waste
Maintains only the minimum flow the pump actually needs — no extra power burned pushing system process flow plus a full recycle stream around the clock.
Maintenance friendly
The only upkeep is exchanging the soft parts and cleaning the internals at the annual inspection, and changing the springs every 3–5 years depending on operating conditions.
Essential safety
Designed to prevent the overheating, serious noise, instability and erosion that damage a centrifugal pump at low load — in a compact body with low installation and maintenance cost.
Model range
ZDT · ZDL · ZDM
Three families cover everything from utility pumps to high-pressure boiler-feed service — up to CL2500 and a 30 MPa bypass drop. Tell us the pump curve and duty and we’ll quote the right model.
Request a Quote →| Model | Rating | Size | Max ΔP |
|---|---|---|---|
| ZDT | CL150 – CL400 | 1" – 16" | 4 MPa Type-T bypass for large bypass flow. |
| ZDL | CL150 – CL600 | 1" – 20" | 6 MPa Unique L-bypass eliminates noise and prevents cavitation. |
| ZDM | CL150 – CL2500 | 1" – 20" | 30 MPa Multistage-decompression M-bypass for high-pressure service. |
ANSI B16.34 Class 150–2500 · flange options DIN, BS, JIS, RTJ, FF. Ranges per published data; confirmed against the datasheet at quotation.
Where they run
Applications
Wherever a centrifugal pump can be throttled, recycled or run at part-load, it can drop below its safe minimum flow — and that is exactly where an ARC valve earns its place. Boiler-feed pumps are the classic case, but the same risk applies to charge, reflux, transfer, injection, circulation and fire-water duties across heavy industry, where a single low-flow event can cost a pump rebuild and an unplanned outage.
Because the valve is self-operating and suitable for a wide range of fluids — from cold water and process liquids to hot boiler feedwater — it fits a broad spread of plants without instrument air, power or a control loop. ACD supplies the ZDT, ZDL and ZDM models sized to your pump curve so the protection matches the service, not a generic catalog number.
Industries served
- Chemical
- Petrochemical
- Steel
- Fire protection
- Power plants
- Paper-making
- Shipping
- Environmental
The manufacturer
Built by Datian — supplied by ACD
Shanghai Datian Valve Pipe Engineering has spent nearly two decades building industrial valves to GB, ANSI, API, JIS, DIN and BS standards. ACD America is Datian’s appointed sales representative in the Americas — so you source genuine Datian valves, in your timezone and currency, fast quotes, shipped from our Orlando, FL warehouse.
- DN6 – DN3000
- Size range (full Datian line)
- 0.6 – 42 MPa
- Pressure range (full Datian line)
More from Datian
Related products
The valves Datian builds around minimum-flow pump protection — available through ACD.
Back Pressure Valve (YB7)
Special pressure-control valve for duties a standard control loop can’t handle — pairs with the ARC valve.
View product →
Multistage Minimum Flow Control Valve
Multilevel cage / symmetric sleeve trim that cuts noise and cavitation in high-pressure gas or steam.
View product →
Protecting a pump from low flow?
Send us the pump curve or the duty — we’ll size the right ARC model and quote it.