Control the discharge of separated liquid phases in batch processing, washing and recovery duties.
After an immiscible liquid mixture settles, the heavier phase lies below the lighter one. The Belfield valve uses that specific-gravity difference to control the main discharge as the interface reaches its float chamber.
The mechanism remains open in the heavier liquid and closes as the lighter liquid arrives. Which phase is recovered, retained or discharged depends on the vessel and outlet arrangement.
For chemical processing, selection must bring together liquid properties, wetted-material and seal compatibility, operating conditions and the intended recovery route.
Decant a separated phase after the specified settling period. Confirm that the interface is distinct and stable before starting the discharge.
Review water washes and immiscible solvent or product phases. Identify the valuable phase and the destination of each discharge.
Help retain a separate unwanted phase at the vessel outlet. Include downstream treatment, monitoring and abnormal operating conditions in the review.
Supply specific gravity and viscosity for both phases at minimum, normal and maximum operating temperatures. If a batch changes composition, identify the closest density difference and the conditions at each stage.
A float configured for one pair of liquids should not be assumed suitable for another. Persistent emulsions or small and variable density differences can change the application assessment.
Carbon steel and stainless steel bodies are available with stainless steel internals. The body, internals, seals and connections must suit the actual chemicals and cleaning conditions.
Provide any corrosion, contamination or material requirements at enquiry stage. Unusual fluids or construction requirements need manufacturer review.
Identify both phases, their specific gravities and viscosities at operating temperature. Include solids, emulsions and wax where present.
Provide minimum, normal and maximum temperature and pressure, required flow, available head and downstream backpressure.
Include connection sizes, wetted-material and seal requirements, the discharge route, and a vessel or P&ID sketch.
PMA has supported process measurement and analysis since 1971. We bring the valve and its application together: the liquids, the vessel, the discharge route and the information your team needs.
Share your process conditions and a vessel or piping sketch. Our team can help you review selection, installation requirements and ongoing support.
Published operation, materials, model capacities and application limits.
Installation and operating guidance for the configured valve and process duty.
Explore the wider Belfield technical library and application background.
No. It controls discharge after immiscible liquids have settled into separate phases. It does not break emulsions or remove dissolved material.
That must be reviewed against the liquid identities, density differences, temperatures and compositions at each stage. Do not assume a single float setting suits every liquid pair.
Recovery depends on the vessel, main discharge and any side run-off arrangement. PMA will review which phase should be retained or recovered and how each outlet is routed.
Speak to the PMA team about your instruments, reagents or service requirements. Tell us what you need, and we’ll help you find the right next step.
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