Position:HOme > Knowledge > Smart Measurement

How to classify remote water meters?

Source:Wasion group Author:admin Date:2012/7/13 11:13:38

           1.Brief Introduction
Smart remote water meters consist of transmitting water meters and electronic acquisition modules. The electronic modules acquire signals, process, store, and upload data through telecommunications lines to repeaters or hand-hold meter reader. The meters are designed within one integral structure, which will record and store users’ real-time water consumption. Each water meter has a unique code. When receiving reading instructions, smart water meters can immediately upload the data onto the management system.

2.Major Control Parameters
Smart remote water meters are made on the basis of mechanical cold (hot) water meters, plus remote transmission system. Major control parameters adopted by the meters include flow, normal flow, overload flow, minimum flow, boundary flow, nominal pressure, maximum allowable working pressure and pressure loss, among others.

3.Classification of Remote Water Meters
According to electromechanical modes, remote water meters are divided into: remote water meter with real-time transformation, and direct reading remote water meter.
According to rotary vane structure, they are divided into: helical-vane remote water meter and rotary-wing remote water meter.
According to the type of computing immersion, they are classified as: dry-type remote water meter and wet-type water meter.

4.How to Choose Remote Water Meters  

1)The first factor that needs to consider is the working environment of the water meter: such as water temperature, working pressure, working time, measurement scope, and water quality. Then, determine the caliber of the meter according to the flow designed to go through the meter, which should produce pressure losses near or less than the specified ones. Generally, WHEN THE nominal diameter is less than DN50, rotary-wing water meter is the choice; when the nominal diameter is larger than DN50, helical-vane water meter is the right one; if the flow fluctuates a lot, it’s better to choose a combination water meter. Priorities should be given to wet-type water meters in domestic design. 

2)When the water use is equal, the nominal diameter is determined by designed flow per second not exceeding the normal flow of the meter. When there is fire flow, it will be necessary to check the flow so as to ensure that the total flow will not exceed the maximum flow limit of the meter.

5.Tips for Construction and Installation

1)The water meter should be installed in places that facilitates repair and reading and prevent exposure to sunshine, freezing, pollution and damage to the meter.

2)Helical-vane water meters should be located behind a straight pipeline with a diameter that is 8-10 times the nominal diameter of the meter while for other types of water meters, a straight pipeline with a diameter no less than 300mm should be in front or behind the meters.

3)Rotary-wing water meters and vertical helical-vane water meters should be installed horizontally; horizontal helical-vane water meters and displacement water meters should be horizontally, slant or vertically installed, depending on actual conditions; when the meters are vertically installed, the water must flow from bottom to up.
4)For water supply systems that combine living, production and fire, if there is only one inlet pipe, a bypass pipeline should be installed around the water meter.

5)Service valves should be installed in front and behind the meter and on the bypass pipe, and drain devices should be installed with the meter and the valve behind the meter. To reduce head loss and ensure that water in the pipe in front of the meter flows straightly, it’s better to adopt gate valves as the service valve in front of the meter. It is not a must to put service valves behind the meter and specific drain devices for household water meters.

6)Water meter chambers should be protected from flood and rain.

7)The direction of the meter needs to be consistent with its type.

8)Check valves should be put behind the water meter when the meter may reverse, the measurement may be affected and the meter may be damaged.

9)It is basically the same to install a cold water meter and a hot one, except different working temperature. The maximum working temperature of hot water meters is 110℃. Check valves should set behind the meter to prevent back flow if a hot water meter is installed in front of boilers or heat exchangers.

10)Remote water meters can be installed in two ways. It is easy to install a remote water meter that is only used for outdoor meter reading: it just needs to connect the output system of the meter with the data display device installed outdoor (the repeater). The other way is to connect all remote water meters in a building or community with the community’s management agencies through repeaters and network controllers and achieve uniform management through terminal devices.

6. Implemented Standards

1) Product Standards
Electronic Remote Water Meters CJ/T 224-2006

2)Construction Standards
Code for Acceptance of Construction Quality of Water Supply, Drainage and Heating Works GB50242-2002

Code for Design of Building Water Supply and Drainage GB50015-2003
Long-range transmission meter reading system for Residence—Special Line Transmission for Data JG/T162-2004
Technical Requirements of Utility Meters Data Transmission CJ/T188-2004