caleffi safety valve made in china

This function is performed by pressure reducing valves, i.e. devices that makes it possible to regulate the outlet pressure to predetermined optimal values.

Opening a tap on the circuit downstream from the pressure reducing valve causes a reduction in pressure below the diaphragm. The force of the spring is now able to overcome the force exerted by the water under the diaphragm: the spring forces the obturator downward to allow water to flow through the valve.

When all taps downstream of the pressure reducing valve are closed, the pressure below the diaphragm increases until equalising the thrust force (setting) of the spring. The obturator closes, maintaining the downstream pressure at the setting value.

... PRESSURE REDUCING VALVE SETTING involves setting the working pressure by adjusting the spring. To increase the setting simply turn the knob clockwise; the spring is compressed so that a higher downstream pressure value is needed to counter it. Valve setting must be carried out with all downstream taps closed. To perform this operation it is generally necessary to install a pressure gauge downstream of the pressure reducing valve.

... movement of the Caleffi pressure reducing valve obturator is unaffected by upstream pressure; thischaracteristic, which is essential for a pressure reducing valve, is achieved through the use of a "compensated seat":the obturator seat is designed in such a way that it has the same thrust surface area both upwards and downwards.

... the pressure reducing valve is frequently installed in homes: one of the most important features is the absence of noiseduring operation of the valve. Caleffi pressure reducing valves feature the perfect sectional profile in the area of the highest flow velocity to ensure extremely low noise levels.

The 311, 312, 313, 314, 513 and 514 series safety relief valves are made by Caleffi S.p.A. in compliance with the essential safety requirements laid down by Directive 97/23/CE of the European Parliament and the Council of the European Union for harmonisation of member States with regard to pressurised equipment.