Buy Brass Manifolds

* The table of brass manifolds indicates the Possible field of application is aimed at giving engineers a quick general reference in order for them to choose the manifold most suitable for the size of a certain heating system. The suggestions given can be used, for example, when making an offer where no specific data is available or when making budget estimates.



The Manifolds for underfloor systems make the parallel supply of terminal fluid circuits possible, with the following objectives and advantages:

  • limited dimensions which make it possible to fit the manifolds in wall-boxes, even in partition
  • Manual or automatic switching on and off of individual circuits. Auto switching is made possible by fitting electro thermal actuators QMAH230, controlled by room thermostats and programmable stats on the valves with thermostat
  • Micrometric flow regulation in order to balance the various
  • The calibration turns made are shown in numeric values on the body of the
  • Possibility of checking the performance of circuits by fitting thermometers and flow-meters.


The Manifolds for underfloor systems are supplied complete with the following pre-fitted accessories:

  • micrometric Lockshield valves with hand-wheel
  • flow-metres for reading the flow rate, with incorporated reading valve

pair of brackets for fixing the manifolds in housing boxes (assemblies shown in the price-list only: see relevant section in this sheet).


The Brass manifolds are particularly suitable for supplying low temperature circuits serving:

  • underfloor heating systems.
  • fan-coil supplying systems with two pipes, with or without seasonal fluid inversion.

These manifolds can be used for traditional heating systems using radiators.


The different versions of Manifolds for underfloor systems can be equipped with various accessories chosen according to the specific requirements of designers or installers.

The various possibilities of connection to the terminal circuits  are shown under the “Accessories” paragraph.

It is important to keep in mind that the  availability  of accessories such as flow-meters and thermometers allows  quick control of the design functional parameters during calibration and commissioning and, importantly, in the case of performance disputes.



Body  :  Nickel plated brass

Valve seals  :  EPDM

Hand-wheels and caps   :  ABS

Junction fittings  :  Euroconus (G 3/4” UNI-EN-ISO 228)

In-line fittings  :  F 1” UNI-EN-ISO 228


Maximum operating pressure  : 1000 KPa

Differential pressure Δpmax  : 100 KPa
(only for manifolds with thermostat option)

Max. permitted temperature

Manifold kit with Lockshield valves: +5 ÷ +100°C

Manifold kit with flow-meters : +5 ÷ +80°C

Fluid permitted                              : water; water + glycol* 50%

Flow-meter                                    : 1 ÷ 4 l/min.

Flow-meter precision            : ± 10%



Lockshield valve pressure drop

Pressure drop of the valve with thermostat option and servo-motor


Flow-meter pressure drop


Manifold pressure drop


Fitting pressure drop


When balancing circuits, avoid excessive constriction of the lockshield adjustment valves and of the flow-meters. The turbulence which could arise from such constrictions could cause irritating noise and vibrations and an excessive dissolution of gases, which is the main cause of occlusion of particularly tortuous circuits (radiating underfloor systems).

In these cases, reduce the gap between hydraulically more favoured circuits and the circuit which is less so, by distributing the flow rate of the latter between two or more circuits.

In order to determine the total pressure drop, add the pressure drop generated by the lockshield valve, the valve, the flow- meter and the fittings to the passage of the flow rate of each individual circuit. The pressure drop generated by the manifold at the time of passage of the overall flow rate can be considered negligible in comparison with the pressure drop generated by lockshield valves, flow-meters and valves.


We advise complying with the following prescriptions when installing Brass distribution manifolds.

  • Before connecting the Brass distribution manifold, flush all the tubes of the system upstream and downstream in order to remove any threading, welding, lubricant and solvent residue remaining in the heating
  • Keep to the flow direction stamped on the individual
  • Move the thermostatic valves and the flow meters into the “all open” position.
  • Pay particular attention to the filling of the circuit operations. Fill and remove air from one circuit at a time. For floor  systems carefully follow the instructions provided by the
  • The fluid circulating must be limpid and without suspensions which could damage the sealing seats of the plugs and/or deposit inside the manifolds and in the floor

If possible insert a suitable ex-tractable Y filter before the Brass distribution manifold.

  • We recommend applying protection to the manifold as to avoid deterioration of the manifold during plastering/decorating

NB: It is mandatory to mount the brass manifold complete with flow meter on the hydraulic flow circuit.




Correct installation of manifold with flow meter


For additional information consult the optional accessories technical sheets, and comply with the installation instructions, use and maintenance provided in the enclosed instructions with the components supplied.





Manifolds with flow meters and delivery adjustment valves incorporated.

The flow meter present on the manifold is able to carry out the following operations:

  • Measure the delivery: direct reading of the delivery
  • Interception and adjustment of the delivery: due to the incorporated adjustment


Using the incorporated adjustment valve in the flow meter, the delivery of the individual circuits can be adjusted by the operator to the amount required, read directly on the indicator rod of the flow meter, and by direct use of the same.

The flow meter has a scale limit of 1 ÷ 4 I/min (60 ÷ 240 I/h).

Following the adjustment, the valve can be locked in the position it is in, by means of the locking cover that also acts as an adjustment to the flow. The same valve enables the circuit in question to be closed.


The Brass manifold with the flow meter must always be positioned on the flow side of the circuit it is connected to. Incorrect positioning of the manifold causes malfunction of the flow meter.


The adjustment valve group and flow meter  is  dismountable and replaceable with the appropriate spare part.


Locking system of the degree of opening of the flow meter, allowing at the re-opening of the circuit, the lock of the stroke at the exact position of initial setting (project value).

  • Set the regulation of the flow meter to the project value. The white hand wheel has to be removed during this operation;
  • Screw the ring of "Memory-Stop" counter-clockwise (left thread) until you reach the stop stroke;
  • Replace the white hand wheel. Turn the hand wheel (clockwise), you can close the single circuit. Turning the opposite direction until it locks you can open the circuit, until the setting of the project value.

Through the two holes on the hand wheel, you can plunge the flow meter, in order to avoid the tampering of  the setting adjustment.

Warning: DO NOT use tools for operation, only hand adjust the flow meter.

underfloor accessories

The terminal units and the by-pass unit are equipped with a filling unit with threaded pressure gauge holder connection F G 1/8".

  • Use a manometer Ø 40 with a 16 bar G1/8” radial coupling code 005 for connection to automatic/manual thermal units.
  • Use a Ø 40 pressure gauge with a 10 bar G1/8” axial coupling code  832.005 for connection to the by-pass unit.



underfloor accessories




1 QBVG1 qbvg1

Ball valve with total passage, FM 1" union fitting, with hand-wheel complete with dial thermometer scale (0...80 °C) with OR seal fitting.

B = Blue butterfly valve / R = Red butterfly valve


QBV1 qbv1 Ball valve with total passage, FM 1" union fitting. B = Blue butterfly valve / R = Red butterfly valve
3A QAVDG1 qavdg1

End group for automatic discharge of air and water. Mounted on return manifold

Union 1” M

3B Incl in QAVDG1 incl-in-qavdg1

End group for manual discharge of air and water. Mounted on flow side of manifold.

Union 1” M

4 QMAH230 qmah230 Servomotor for electro-thermal control for thermostatic valves, with or without micro limit switch. Valve position Normally Closed in the absence of power. Power supply 230 V AC or 24 V AC.
5 Q2250.00.12 q2250-00-12 Flow meter with regulation valve and flow rate indicator function. 1 ÷ 4 I/min (60 ÷ 240 I/h). Spare part.
6 TQEC16 qec16 Fitting for multi-layer polyethylene pipe, ø14 ÷ 20 mm, thickness 2 ÷ 2,5 mm.  F 3/4" Euroconus threaded connection.


QMB2 2
QMB3 3
QMB4 4
QMB5 5
QMB6 6
QMB7 7
QMB8 8
QMB9 9
QMB10 10
QMB11 11
QMB12 12






  • 1 multi-way    manifold   group    with    flow-meters, lockshield and flow indicator
  • 1 multi-way manifold group, complete with valves with thermostat option and with manual hand-wheel.
  • 1 pair of polymer brackets for fixing.

Limit switch contacts to the individual boiler or to the zone valve

Feeding an underfloor system

Thermal zone with thermally independent bathroom, even during operating times (e.g. sleeping zone attenuated, bathroom warm).

(A) Circuits thermally independent, but tied to the operation and attenuation of the thermal zone timer- thermostat.

(B) Areas controlled by the thermal zone timer- thermostat.

(C) Bathroom controlled by independent timer-thermostat.

To the individual boiler or to the zone valve

Feeding a heating system using radiators

Thermal zone controlled by room timer-thermostat with temperature regulation on two levels

(A) Circuits controlled by room thermostat or timer- thermostat acting on electro - thermal commands (solution for premises with free internal and/or external loads

(B) Circuits without automatic interceptio

(C) Heated towel rail feed circuit with thermostatic

Qualitas reserves the right to make improvements and changes to the product described and to its technical details (supplied only as guide indications) at any moment and without notice: always refer to: the instructions enclosed with the components supplied.
This sheet is an aid, and provided as schematics. 
Qualitas assumes no responsibility for the results obtained by using the schematics.