BRV Bonetti Rubinetterie Valduggia S.r.l.


Regolare e distribuire energia pulita

726 - Basic Series

Anti-scald thermostatic mixing valve for medium and small applications. Compact size. Available Kvs: 1.5, 1.8 and 3.4.

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Mixing kit for ModvFresh Basic

35÷60°C thermostatic mixing kit designed for ModvFresh Basic, with anti-scald thermostatic mixing valve for small applications.

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ModvFresh Basic

Compact heat exchange unit to deliver fresh domestic hot water (DHW).

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°Caleon Thermostat - Wi-Fi

Elegant chrono-thermostat with TFT capacitive touch panel. Wi-Fi N 2.4 Ghz connection for remote control by °Caleon app.

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Full bore 2-way zone ball valve, with bidirectional actuator with quick connection. Dimensions from 1/2" DN15 to 1"1/4 DN32.

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Multifunctional compact hydraulic module for the management of a direct circuit, a mixed circuit and the production of domestic hot water (DHW)

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DomvS Clima

Control unit for manifolds of heating and cooling radiant panels up to 200 m2. Fixed point thermostatic mixer or motorized rotary mixing valve. LCD room control unit.

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Modular multi-zone distribution box for wall-mounted gas boilers or heat pumps. Three types of available pump units: direct, mixed motorized, mixed fixed point.

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Technical part

Technical part: Ball valves
Standard ball valves are suitable for employment with steam, water, oils, hydrocarbons,  and generally with all non aggressive fluids. The use is recommended only with the ball fully open or closed; in fact this system is not suitable to the adjustment, that may give rise to deformations of the seal gaskets. The linear manufacturing allows to have very low head losses.
According to the different models, two rod seal systems are available: with packing gland  or with double O-ring.


The rod seal by means of packing gland is the more used system in the standard ball valves. Two special gaskets made of PTFE,  kept in compression by the packing gland, assure the seal and in the meantime the right handling of the adjustment rod. The guarantee of long life of the models of ball valves that have this seal system is due to the possibility to re-establish the right compression of the gaskets, if necessary (for instance owing to sudden thermic shocks), by simply operating on the packing gland.


The rod seal system by means of double O-ring made of EPDM Peroxide, tested for several years  in the models of ball valves special for combustible gas , is used even  in the ranges of models suitable for high pressure and temperature. Particularly all the ball valves used as components of pump units, of heating and solar systems, and the filter ball valves.

The head losses in a hydraulic system are represented, in addition to the pressure drop of the pipings, also by the pressure drops due to isolating equipments.
Taking  into consideration that the value of the head losses (Kvs) is proportional to the kinetic energy of the fluid and to experimental coefficients,  its mathematical calculation is always very difficult. Kvs is le flow rate in m3/h, at the temperature of 15,5°C, that gives a pressure drop of 1 bar with the valve fully open.
Roughly the Kvs of the head loss is given by the following formula:

Q is flow rate expressed in m3/h.
Ph [bar] is pressure drop measured at valve's ends, at a set distance.

If the Kvs value is known, it is possible to calculate the flow rate (Q) if the differential pressure value is known (Ph) or vice versa, according to the following diagram. This diagram is referred to the use of water, therefore if a different fluid is used the difference of density must be taken into consideration.
Diagram flow rate/pressure drop of standard ball valves

Diagram flow rate/headloss of Checkball valves series

In the following table you can find the Kvs valves of the different DN sizes of the standard and checkball ball valves series.

8 10 15 20 25 32 40 50 63 74 94
Kvs Standard ball valves
6 9 18 39 71 119 196 300 525 870 1270
Kvs Checkball - - 2,7 4,5 7,6 - - - - - -


To make the flow rate/pressure tests of current production samples and prototypes, BRV has prepared a test bench equipped with a digital pressure gauge and with a inductive magnet flow meter. This equipment allows to test the most of the valves manufactured by BRV.

Pressure drops/flow rate test bench
(click to download PDF)


The following diagrams show, for any ball valve size, the changing of the nominal pressure according to the working temperature. In fact at high temperatures  the allowed working pressure is going down. These diagrams are valid for the use of water, oils and generally for all non aggressive fluids.
Ball valves PN 30 series

Ball valves PN 40 series

Checkball valves series


The following table shows the maximum operation torques necessary to opening/closing workings for the different sizes of ball valves:

10 15 20 25 32 40 50 63 74 94
Mt [Nm]
35 35 35 50 50 105 105 502 502 502
Tw [Nm]
1,5 2,5 3 5 7 5 12 15 17 20
Ts [Nm]
3 5 6 10 14 20 24 30 34 40

Mt is the maximum couple torque to which the rod may resist. The Tw (working torque) and Ts values (starting torque) must be considered as approximate, because they  substantially change in accordance to the working conditions, to the recurrence  and to the type of fluid.
The values of the table have been got from a test session carried out on new valves (never used) with perfectly lubricated seals, at a temperature of 20°C and with a test pressure of 6 bar.


The purpose of the test is the check of the hydraulic seal of a ball valve after a long series of cycles open/close. The valve under test is the art.510 ½” that is one of the most significant models of the range of standard ball valves, moreover several other models have the same engineering, only the outlets are different.
The test was carried out doing 10.000 cycles open/close on the test valve, mounted on the test installation, under the conditions of the following table:

DN Working torque Tw
Temperature [°C] Pressure test
[kPa (bar)]
Flow rate
510 1/2" 2,5 93°C 400 (0,4) 0,2

After 10.000 cycles the valve was tested at the pressures of 16 and 0.2 bar, in order to check the inside and outside seal (gaskets seal). The test conditions and the results are carried in the following tables:

Test with closed valve
Test period
Pressure test
[kPa (bar)]
Test result
3,5 900 1st test: 1600 (16) / 2nd test: 20 (0,2) Ok
21 3,5 900 1st test: 1600 (16) / 2nd test: 20 (0,2) Ok

 Test with open valve and closed defluxion

Test period
Pressure test
[kPa (bar)]
Test result
900 1st test: 1600 (16) / 2nd test: 20 (0,2) Ok
21 900 1st test: 1600 (16) / 2nd test: 20 (0,2) Ok


In the standard ball valves with packing gland seal, if it is necessary to re-establish the compression of the rod seal, we advise to follow the values of the closing torque as shown in the following table:
10 15 20 25 32 40 50 63 74 94
Corresponding Size
1st size 2nd size 3rd size 4th size
Closing torque [Nm]
12 12 20 45