Caleffi 548052 DN50 Flanged Hydraulic Separator PN16

The 548052 is the DN 50 flanged hydraulic separator of the Caleffi 548 series. It is a steel vessel installed between a primary production circuit with its own pump, such as a chiller or boiler, and a secondary distribution circuit, so that each pump can run without disturbing the other. It comes with an air vent, a drain valve, probe holder connections and 60 mm insulation already fitted.

Making two pumped circuits independent

When a primary circuit and a secondary circuit each have pumps, the pumps can interact and cause abnormal swings in flow and head. The separator creates a low pressure-drop zone, so the flow in one circuit does not drive flow in the other. The datasheet puts it plainly: with the secondary pump off, the entire primary flow bypasses through the separator, and the primary can run at constant flow while the secondary varies, which is how modern heating and cooling plants are built. Three balance cases are shown: primary equal to, greater than or less than secondary flow.

Key features from the datasheet

• Epoxy-resin-coated steel body with PN 16 flanges at DN 50 for coupling to flat counter-flanges to EN 1092-1
• Automatic air vent with a 3/4 inch connection, a ball valve to shut it off for maintenance, and a 3/8 inch discharge connection
• Drain valve for sludge with 1 1/4 inch connection that can be operated while the system runs
• 1/2 inch probe-holder connections on both flow and return channels; separator connections are reversible between primary and secondary
• Supplied with rigid closed-cell polyurethane foam insulation and embossed aluminium cover, usable in chilled-water circuits
• Glycol allowance up to 50 % on the flanged version

Technical specification

Overall dimensions are given in the datasheet drawing; confirm space and counter-flange spacing before ordering.

Selection and ordering guide

Size the separator by the larger of the sum of primary flows or the sum of secondary flows, against the maximum recommended inlet flow. The 548 series spans threaded and flanged bodies up to DN 300; the 5495 series is a multi-function type that adds deaeration, dirt separation and magnetic capture.

Flow values follow the datasheet row order for the 13 sizes; check the sizes against the printed table before ordering.

Installation and operation notes

• Flanged models shut the air vent off with a ball valve; threaded models close the vent body automatically when it is removed.
• Open the ball shut-off cock on the drain to expel sludge; the cock can be used with the system running.
• Use the 1/2 inch probe-holder connections for temperature probes or gauges on flow and return; flanged units have both channels.
• The datasheet refers to the Caleffi Idraulica magazine no. 18, pages 7 to 11, for temperature variations caused by separators.
• Insulation: the flanged series to DN 100 uses a polyurethane shell with aluminium cover, and DN 125 and 150 use PE-X.

Applications in Gulf chilled-water and heating plants

A hydraulic separator is a staple between chiller or boiler primary loops and building secondary loops in hotels, hospitals, malls and district-cooling interface rooms across Oman and the GCC, where several chillers with constant-flow primary pumps feed variable-flow air-handling-unit circuits. The DN 50 size suits a small plant with about 9 m³/h at the inlet. The datasheet restricts the medium to water and non-hazardous glycol solutions at 10 bar and 110 degrees C.

Selection and installation notes

Hydronic components are selected from the design flow, the pressure drop and the maximum working pressure and temperature of the circuit. Check the connection size and thread type, fit isolating valves so the part can be serviced, flush the pipework before commissioning and respect the flow direction marked on the body. Insulate heating and chilled-water parts according to the project specification.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Related items

The datasheet distinguishes the 548 series from the 5495 multi-function separator, which adds deaeration, dirt separation and magnetic capture. It also lists a mixing-valve and climate-controller application diagram. Quote by exact code and confirm flange standard and insulation before ordering.

Documents and quotation

The official Caleffi 548 and 5495 series datasheet 01404/24 EN (2024) is linked on this page. Send the code, quantity and primary and secondary flow rates to request a quotation. See more in Hydraulic Valves & Components.