In this section is possible to find answers to FAQ asked by our users.

Question:
How can I correctly read the meter dial? Go>>>

Question:
What is the correct installing procedure for single and for multijet meters? Go>>>

Question:
What is the correct installing procedure for helical vane Woltmann meters? Go>>>

Question:
How can I correctly read the meter dial?

Answer:
The water meter, being a measuring instrument, is used to determine visually, by the dial,  the volume of water passed inside it; it is necessary so, for its correct use, to know how to read the dial.

The rolling numbers show the cubic meters -the last to the right is bigger in order to make the reading easier when is coming the next number-

The red pointers of the little dials  show the submultiples of the cubic meters and, making the transformation of the cubic meter, you can get the reading in litres –0.001 cubic meter=1 litre) What’s more, the little dial marked with x 0.0001 has the double division to read up  the twentieth part of a liter, for higher precision (see Picture 1).

Pic. 1

For example the dial, shown in picture 1, reads a value of 3742 cube meters (the last rolling number is halfway between the number 2 and the number 3, therefore the lowest numerical number must be taken into account).
On the other hand, the little dials show:

1. dial marked by x 0,1: value 3 (being halfway between 3 and 4), equal to 0,3 m³, i.e. 300 litres
2. dial marked by x 0,01: value 6 (being halfway between 6 and 7), equal to 0,06 m³, i.e. 60 litres
3. dial marked by x 0,001: value 3 ( being halfway between 3 and 4), equal to 0,003 m³, i.e. 3 litres
4. dial marked by x 0,0001: value 6,6 (being slightly forward, as compared to the halfway between 6 and 7), therefore 0,00066 m³, i.e. 6,6 decilitre

 The sum of all the above value is :

3.742,36366 m³

Usually, when reading is made for invoicing, the municipalities take into account just the digits before the comma, I.e., cube meters only.

Question:
What is the correct installing procedure for single and for multijet meters?

Answer:
For a correct installation of the water meters You are required to follow these instructions:

1. polish accurately the two tube sections where the meter has to be installed (especially if it is a new plant) , removing foreign substances (like hemp filaments, calcareous sediments, welding slags and so on..), let water flows far some minutes by connecting a threaded tube having the same length of the water meter to the main connection;
2. install the water meter perfectly horizontal being sure the  water flow is in the direction of the arrow stamped on the meter body.
   The horizontal installation is very important for a good performance and must be checked in longitude and transversally;
3. install the meter in a place protected by freezing, eventually cover it with insulating material;
4. install it in position guaranteeing an easy reading, protected by shocks and tampering;
5. it is better to avoid water meters installation immediately after equipments or tubes which may cause water beddies and an irregular flow of the water, they may cause a bad accuracy. In this case it is suggested to install the water meter with distance of at least 10 times the water meter diameter far from valves, flood gates, cocks, portion of curved or throated tubes and as far as possible from thrust equipments as pumps, autoclaves;
6. install the water meter between two taps, to allow, in case of maintenance, an easy removal. The downstream tap should be able to discharge the water to empty the meters in case of frost or in case of removal for maintenance.

Please note: to keep all meter components in good working conditions, we recommend to ensure that the meters are always full of water (with the exception of short periods only for maintenance).

Question:
What is the correct installing procedure for helical vane Woltmann meters?

Answer:
Woltmann meters are identified by blue housings for cold water and red ones for hot water. For both these models, the same instructions apply for installation and operations. The operating temperature of Tmax 50°C for cold water or Tmax 120°C or 130°C with raised register for hot water must be complied with.
Woltmann meters should be installed in locations which are frost –protected and easily accessible for reading. Only sealings suitable drinking water may be used for installation. If the pipe diameter is different from your meter’s nominal diameter, you must use flanged adapters.
We recommend to be extra cautious when undoing and removing the internal mechanism, considering the proper installation position; in case of maintenance o repair, internal mechanism and components can be removed from their housing, without need to change the full meter. The housing can be closed by a special lid, available on request. In case the Woltmann must be removed completely from its place, it is necessary to use a flanged trunk as replacement.
Vertical Woltmann are fitted with a special airhole, placed on the head side, and covered by a threaded cap.
No abrupt changes in cross-sectional area must be allowed immediately upstream and downstream of the meters.
The measuring points must be located such that it is ensured that the meters are always completely filled with water.
A straight, undisturbed pipe section in front of or behind the meters is necessary in the same diameter as the meters. It must be 10 times as long as the nominal diameter upstream of the meter, and 10 times as long downstream.
At narrow measuring points, shutoff gate valves can be installed immediately upstream and downstream of the meters, provided they are always completely open during operation. Woltmann meters must be installed as far as possible  from pumps.
New or modified piping must be thoroughly flushed at high pressure as possible in order to remove any foreign matter. For this process , install a pipe spacer in place of the meters.
After flushing, you can install the meters. Make sure the direction of flow corresponds to the arrows marked on the meters for this purpose. We recommend to insert an -Y strainer upstream the meter.
When putting into operation, and also after every draining of the pipes, you must always make sure that the shutoff valves are opened slowly, so as to provide a gentle start-up for the meters, which will initially be running in dry operation.
In order to avoid incorrect registering and damage, water-air or water-steam mixtures may never flow thorough the meters.
Strictly avoid to weld the counterflanges with the installed meter.
From past experience, special components placed just downstream the meter, does not affect the hydraulic performances, but the counterthrust wears quicker the turbin bearings. We suggest therefore, when possible, to place downstream a  straight, undisturbed pipe section 5 times as long as the water meter nominal diameter.

GATE VALVES or NON RETURN VALVES UPSTREAM THE METER

When a gate valve is present upstream the meter, we recommend to keep a distance of at least 12 DN.  If in doubt that the gate valve is always open, the distance can be lowered to 4-5 DN for horizonal Woltmann; for vertical Woltmann it is enough 2 DN.
When a non return valve is present, the distance is 12 DN.

BENT and "T" PIECE UPSTREAM THE METER

In such cases, we recommend to install a divider for fluids, o it is necessary to have a straight pipe section by minimum 25 DN and for vertical Woltmann by 3 DN.
This applies also in case bents and "T" pieces are at the same level.

FREE DRAINPIPE DOWNSTREAM THE METER

The drainpipe must be placed upper the water meter, to allow that the latter is always full.

AIR IN THE PIPE NETWORK

The meter must be installed so that it is always full of water, to avoid air lock inside the pipe network.