Water meters

Installation

The reliable functioning of these instruments largely depends on their correct installation. The user of the water meter is also responsible for ensuring that the design and installation of the water meter has been carried out in such a way that it complies with the requirements of the regulations. Using professionals for the design and implementation is recommended for housing companies.

It is vital to follow instrument manufacturers' instructions concerning instrument position, straight piping surrounding the instrument, and the installation of possible valves preventing backflow. Otherwise the instrument has not been installed correctly, and it does not fulfil the requirements of the Measuring Instruments Act.

Enough space to install the meter correctly

The installation site of flat-specific water meters must be designed so that the water meter can be installed correctly. The party designing the installation site of a water meter must take the manufacturer’s instructions concerning the installation position and the space required for it into account. There must be enough space to

• install, read, service and replace the meter easily

• install the water meter in the correct position

• Install a sufficiently long section of straight piping both before and after the meter in accordance with the manufacturer’s instructions.

The potential access door must be large enough to allow for measures such as replacing the meter. The manufacturer of the meter can issue a recommendation on its technical service life. The typical technical service life of mechanical water meters is roughly 10 years.

Markings on approved water meters

Manufacturers of water meters compliant with the Measuring Instruments Directive (MID) must issue a declaration of conformity, confirming that instruments fulfil the requirements laid down in the MID. This is shown by a CE marking and other complementary markings on the meter, as shown in Figure 1.

Figure 1. An example of a CE marking compliant with the Measuring Instruments Directive. The letter M and the year reveal the manufacturing year of the instrument. The four-digit number on the right is the code of the inspection body that assessed the instrument's conformity.

Before the Measuring Instruments Directive entered into force, type approval was required for water meters. Type-approved water meters are marked with an EC type approval symbol, shown in Figure 2. The type approval symbol is a stylised letter epsilon, equipped with the code of the country where the approval was issued and the two last digits of the approval year (e.g. D 89) and the approval code (e.g. 6.131.39). New EC type approvals have not been issued after the Measuring Instruments Directive entered into force on 30 October 2006. Selling and installing EC type approved water meters was permitted until 30 October 2016.

Figure 2. An example of an EC type approval symbol.

A water meter may also have a Finnish type approval issued before 30 October 2006. A Finnish type approval follows the format VJ.E.XX.YY, where XX is a sequential number and YY the year the type approval was issued. Issued type approvals were only valid until 30 October 2016 at the latest. Selling and installing water meters with a Finnish type approval was permitted until 30 October 2016.

The use of a type-approved water meter that was commissioned before 30 October 2016 may continue as long as the water meter still functions reliably.

Marking the installation position and flow range of the water meter

The markings on the display panel of the meter indicate the meter’s permitted installation positions. The marking H refers to installation on a horizontal pipe with the display panel facing up. The marking V permits installation of the meter on a horizontal pipe with the display panel facing to the side, or on a vertical pipe. The markings H or V do not permit installation of the meter with the display panel facing down or on a diagonal pipe (standard SFS-EN 14154-2:2005). The permitted installation positions are described in the type approval certificate and/or the meter manufacturer’s instructions.

If there are no H/V markings, the water meter can be installed on either a vertical or a horizontal pipe. A water meter with a H and V marking can be installed horizontally on a pipe with the display facing to the side. Mechanical water meters must not be installed on a horizontal pipe with the display panel facing down, unless such a position has been described in the approval of the meter and the installation instructions.

Water meters installed at present have an R marking in connection with the installation position, such as R80H. The R number must be at least 40. The R number describes the flow range of the water meter. When installed on a vertical pipe, the R rating of a water meter is usually lower than when installed on a horizontal pipe, which means that the meter operates within a narrower flow range on a vertical pipe than when installed on a horizontal pipe.