Meet the Belfield Valve
Automatic liquid separation, made simple
The Belfield Valve automatically drains the heavier of two separated liquid phases and closes when the lighter phase reaches the valve. It separates oil, water and other immiscible liquids by specific gravity—without electrical power, external sensors or continuous operator attention.
Find the Right Solution for Your Process
Explore your application or prepare the data needed to select a Belfield Valve.
Tank Dewatering
Drain settled water from storage tanks and retain the lighter product with an automatically closing, specific-gravity-operated Belfield Valve.
Chemical Decantation
Automate the discharge of separated liquid phases in suitable chemical batch and washing duties, with selection based on your process.
Effluent Protection
Help retain unwanted product at the vessel discharge point before it can reach downstream effluent-treatment equipment.
Size Your Valve
Start with your liquids, flow and available head. Use published model data to prepare an enquiry, not an automatic selection.
Where measurement has met technology for over 50 years.
PMA brings together decades of expertise in water quality instrumentation and process monitoring. Our technologies empower utilities and industries to achieve reliable, data-driven performance.
Instrumentation for various industries
Providers of online instrumentation for the water, oil and gas industry and industrial applications.
Automatic liquid separation
Belfield Valve separates liquid phases automatically using their difference in specific gravity.
Award-winning customer service
On-site support from our experienced service team maintaining our instrumentation across the UK.
Separate liquid phases automatically without interrupting your process.
Specific-gravity sensing
Detect the interface between separated liquids through differential specific gravity, with no continuous operator attention.
Automatic shut-off
The valve remains open for the heavier phase, then closes automatically when the lighter phase reaches the mechanism.
Built for demanding service
Choose carbon steel or stainless steel bodies with stainless internals for gravity-fed or pumped installations.
Recover valuable liquids. Protect downstream treatment.
The Belfield Valve automates phase separation at source, helping operators recover product, reduce contamination and protect downstream treatment processes.
Detect the phase change
Differential specific-gravity operation
The float mechanism responds as the liquid interface reaches the valve, distinguishing phases with as little as approximately 5% specific-gravity difference on average.
Discharge the heavier phase
Measure Automatic shut-off up to 112.5 psig
Install the valve in gravity or pumped systems to discharge the heavier phase until the lighter phase reaches the mechanism and closes the outlet.
What operators need from an automatic decantation valve
The Belfield Valve combines automatic phase detection, controlled discharge and dependable shut-off in one robust mechanical design.
“Detect the liquid interface automatically as the specific gravity changes.”
Interface detection
Differential specific gravity
“Discharge the heavier phase while helping prevent the lighter phase from passing downstream.”
Product protection
Automatic shut-off
“Apply one proven principle across refining, chemical, pharmaceutical and environmental duties.”
Float-position sensing
Remote indication for demanding sites
Automatic phase separation. Reduce manual decanting and improve consistency across tanks, separators and collection systems.
Up to 112.5 psig. Factory-tested protection for robust industrial separation duties.
Built for practical process separation
The Belfield Valve combines automatic phase detection, controlled discharge and dependable shut-off in one robust mechanical design.
Key performance data
75 psig
Specific-gravity sensing
Design pressure for robust industrial liquid-separation duties.
112.5 psig
Factory test pressure
Factory test pressure supporting dependable automatic shut-off in industrial service.
See how the Belfield Valve uses differential specific gravity to automate liquid-liquid separation.
Optional float-position sensing
Remote indication for demanding sites
Optional magnetic proximity sensing can indicate float position remotely, including suitable arrangements for hazardous-area applications.
Specified around your process
Capacity is selected around liquid temperature, viscosity, specific gravity, available head and required flow.
Explore the construction and operating options available for your Belfield Valve application.
Made for demanding process sites
Reliable mechanical operation
The Belfield Valve is engineered for refineries, chemical and pharmaceutical plants, environmental protection systems and other process duties where reliable phase separation matters.
Self-cleaning discharge path
The high-velocity, turbulent seat design promotes a self-cleaning action as the heavier liquid is discharged.
Robust material options
Carbon steel and stainless steel body options support a wide range of process fluids and site conditions.
Review pressure, temperature, viscosity, material and capacity considerations for the Belfield Valve.
Talk to PMA about your separation duty
Whether you are separating water from petroleum products, protecting a floating-roof drain or automating a chemical process, PMA can help specify the right Belfield Valve materials, capacity and configuration.
Let’s talk about your application.
Speak to the PMA team about your Belfield Valve requirements. Tell us about your liquid-separation duty, and we’ll help you find the right next step.
- Advice for your application. Discuss the liquids, flow rate and operating conditions for your process.
- Practical valve support. Get help with sizing, installation, maintenance and replacement parts.
- Clear next steps. Request a quotation or a callback, with your site and application in mind.
- An enquiry, not a mailing list. Your details are used to respond to your enquiry.
Belfield Valve customers
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