Caleffi 536241 1/2 Inch Pressure Reducing Valve with Gauge

The 536241 is the DN 15 (1/2 inch) female-threaded pressure reducing valve with pressure gauge from the Caleffi 5362 series. It takes mains pressure of up to 25 bar and delivers a constant, adjustable downstream pressure between 0.5 and 6 bar, factory set at 3 bar, so that taps, mixers, water heaters and appliances see a stable, safe pressure.

Stabilising mains pressure for a building

The datasheet defines the job simply: reduce and stabilise inlet pressure from the water mains, which is usually too high and too variable for domestic systems. What separates a good reducing valve is that downstream pressure stays constant when the upstream pressure moves. Caleffi achieves that with a compensated seat: a compensating piston with the same area as the obturator cancels the thrust of the upstream pressure, so the set value does not drift. A spring pushes the obturator open and the membrane pushes it closed; they balance at the calibrated pressure.

Key features from the datasheet

• Compensated seat keeps the downstream setting constant despite upstream variations
• Silent operation: below 20 dB in tests and classified in acoustic group I under EN 1567
• Extractable cartridge holds membrane, strainer, seat, obturator and compensation piston, so the strainer can be cleaned without removing the valve body
• PTFE-coated sliding surfaces and PTFE anti-extrusion rings on the compensating piston, allowing continuous use at upstream pressures up to 25 bar
• Stainless-steel seat and strainer
• Pressure gauge fitted (the .1 version), 0 to 10 bar scale, with 1/4″ gauge connection

Technical specification

Selection and ordering guide

The datasheet gives a sizing method: add up the flow rates of the appliances (12 l/min for a bath, kitchen sink or dishwasher, 9 for a shower, 6 for a washbasin, bidet, washing machine or WC), apply the simultaneous-use factor, and choose the diameter that keeps velocity between 1 and 2 m/s.

Nominal flow at 2 m/s: 1.27 m³/h for 1/2″, 2.27 for 3/4″ and 3.6 for 1″. The datasheet worked example selects 3/4″ for 33 l/min with a pressure drop of 0.55 bar.

Installation and setting procedure

• Open all taps before installation to flush the system and expel air.
• Install shut-off valves upstream and downstream; fit on vertical or horizontal pipe but never upside down.
• Close the downstream shut-off valve, turn the spring locking nut under the bell cap with a 10 mm hex key or flat screwdriver (clockwise raises the setting) and read the value on the gauge.
• Below-ground installation is not recommended because of frost, difficult inspection, difficult gauge reading and entry of foreign bodies through the vent holes of the cover.
• Fit an expansion vessel between the reducing valve and a water heater to absorb pressure rise from heating; use water-hammer absorbers in at-risk systems.

Applications in Gulf buildings

Mains pressure in Gulf cities and towers can be high and varies with demand, and booster pump sets add their own pulses. A reducing valve at the base of a riser or at the entry to a villa protects mixers, flexible hoses, water heaters and solenoid valves, and in tall buildings it creates pressure zones. The 536241 is a 1/2 inch residential-size unit; larger risers use the 5365 and 5366 series listed in the same datasheet. The datasheet describes water only, at up to 80 degrees C.

Selection and installation notes

A pressure reducing valve is selected from the inlet pressure, the required downstream pressure and the flow. Fit a strainer upstream, install the valve with the gauge visible, set the downstream pressure while water is flowing and check it again with the flow stopped. Add a safety valve downstream where heating may raise the pressure and provide isolation on both sides for servicing.

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 notes that pressure reducing valves optimise head losses ahead of thermostatic mixing valves, and recommends expansion vessels and water-hammer absorbers in some systems. The 5362 series is interchangeable in length with the 5350 series, per the footnote to the dimension table of the 5360 series.

Frequently asked questions

What does the Caleffi 536241 do?

It reduces and stabilises incoming water pressure, with an adjustable downstream setting of 0.5 to 6 bar, factory set at 3 bar, and a built-in pressure gauge.

What is the maximum inlet pressure?

25 bar upstream, using PTFE anti-extrusion rings on the compensating piston, and up to 80 degrees C.

Is it quiet?

The datasheet reports noise below 20 dB in tests and classifies the valve in acoustic group I under EN 1567.

Can the strainer be cleaned?

Yes. The cartridge holding the membrane, strainer, seat and obturator is extractable, so the strainer can be cleaned without removing the body.

Who supplies the Caleffi 536241 in Oman?

Seven Star LLC is an independent supplier in Muscat and quotes against the exact code. Confirm size, connection type and gauge before ordering.

Documents and quotation

The official Caleffi pressure reducing valve datasheet 01026/17 GB (2017) is linked on this page. Send the code, quantity and flow data to request a quotation. See more in Regulators.