Technical Guide
Water Meters
WRAS Approved Pulse Output Multi-Jet Water Meters
WRAS Approved Pulse Output Woltmann Type Water Meters
Jet range water meters conform to relevant UK and
international standards and approvals, confirming
their suitability for use.
Jet range water meters conform to and surpass
requirements of ISO4064 and European Directive
75/33/EEC Class B when installed in the horizontal
position.
All Jet range water meters are WRAS approved.
Contents
page
Introduction
2
Metrological Performance & Installation 3
Multi-Jet Water Meters
4
Woltmann Type Meters
5
Registers
6-7
2
LOOK OUT
FOR OTHER
Factors such as climate change are putting supplies of
water under greater pressure, its sustainable
management is essential to protect the water
environment and to meet current and future demand.
Part L of the Building Regulations deals with the
conservation of energy in our homes, offices and other
buildings, and it sets high standards for architects,
engineers and contractors to create a more sustainable
built environment.
Sub-metering provides the measurements to identify
where and when energy is being wasted. Designers
wanting to deliver good practice should incorporate
sub-metering in buildings in order to provide the
occupier with the systems to enable the building to be
managed properly.
The Jet range encompasses:
- Multi-Jet water meters in hot and cold types with screwed BSP connections, sizes
ranging from DN15 to 50.
Jet range brochures
- Woltmann Type water meters in hot and cold options with flanged connections, sizes
ranging from DN50 to 200. Larger sizes available upon request.
www.jetrange.co.uk
Introduction
Metrological Performance & Installation
Metrological Performance
Terms of Reference
Qmin
Minimum
The lowest rate at which the water meter will register flow.
Accuracy between Qmin and Qt is no worse than ± 5%.
Qt
Transitional
The rate at which the water meter reaches its highest accuracy ± 2%.
Qn
Nominal (continuous)
The designated normal day to day flow rate for the water meter. Accuracy ± 2%.
Qmax
Maximum (emergency)
The rate beyond which the water meter accuracy cannot be maintained.
Water meters must not be run at maximum flow rate for more than a couple of minutes or the water meter mechanism may be damaged.
Water Meters should be sized between transitional flow (Qt) and nominal flow (Qn).
Typical Error Curve
0
Qmin
Qt
+5%
Qn
Qmax
+2%
0
-2%
3
-5%
Installation
Pulse output
1. The recommended mounting position is horizontal with the dial facing upwards. Never
put the water meter upside down as it will not function correctly.
2. Water meters should always be fitted with a minimum of 5x pipe diameter both up and
downstream. For example, a DN50 water meter would have 250mm (10") either side of
the water meter as straight pipe. This is to ensure accurate reading by reducing water
turbulence. At higher pressures (above 8 bar), this should be increased to 10x pipe
diameter.
3. Note that there is a direction of flow arrow on the water meter. Also, that the water meter
has the size in mm on one side and the maximum flow on the other in metres cubed
per hour. Remember that the water meter must only be used for half of this maximum
flow for constant use, maximum flow only being used for short periods of 1-2 minutes.
4. It is recommended as good practice, to fit a removable filter element before a water
meter to protect the mechanism.
5. Only clean water should be used that does not exceed the temperature specification of
the water meter. This is +30ºC for cold water meters and +90ºC for hot water meters.
6. When installing the reed switch (pulsed output wire), the distance from the water meter
to the control unit/pulse counter is best kept under 40 metres as voltage will drop.
• Pulse output is provided by proven and
reliable reed switch technology
• Approximate lead lengths 1400mm on
Multi-Jet water meters and 1800mm on
Woltmann Type water meters
• Reed switches are normally open, volt
free, but operate on the 0-28 vdc range
when the pulse is made
• A magnet on the water meter will close
the switch to form the circuit when the
pulse specification for the water meter is
reached. This then sends a signal to the
control unit/pulse counter
See water meter performance tables for
specific pulse outputs.
Multi-Jet
Waters Meters
• Sizes 15-50mm
• Surpasses accuracy requirements of
75/33/EEC Class B
• Epoxy powder coated brass bodies
• Integral strainer to protect against large
particles
• Security via tamper evident wire lock
and seal
• Maximum temperatures:
Cold water meters: +30ºC
Hot water meters: +90ºC
• Maximum working pressure: 16 bar
• All major components are recyclable
• Large, easy to read dial with
protective cover
• When using in conjunction with plastic
type pipe, use pipe fittings sized
appropriately to the male threaded union
tail set for that size of water meter as
shown in the table below
• Pulse output included
Multi-Jet Cold Water Meter
Max. Pressure Loss Diagram
15 20 25 32
size - calibre (mm)
1.0
40 50
0.1
0.01
0.001
10.0
15.0
20.0
30.0
35.0
5.0
1.0
0.5
0.1
0.05
0.0001
0.01
pressure loss (bar)
4
B
flow rate (m³/h)
C
A
Performance Data
Cat No.
Cold
Hot
171253
171273
171254
171274
171255
171275
171256
171276
171257
171277
171258
171278
171259
171279
Size DN
(mm)
15
20
25
32
40
50
50
Qmin
l/h
30
50
70
120
200
300
300
Qt
l/h
120
200
280
480
800
1050
1200
Qn
m3/h
1.5
2.5
3.5
6.0
10
15
15
Qmax
m3/h
3.0
5.0
7.0
12
20
30
30
Litres per
Pulse
10
10
10
10
100
100
100
øD
E
Dimensions
Cat No.
Cold
171253
171254
171255
171256
171257
171258
171259
Hot
171273
171274
171275
171276
171277
171278
171279
Cat No.
Unions
N22009
N22010
N22011
N22012
N22013
N22014
Flanged
Multi-Jet Water Meters
Size DN
(mm)
15
20
25
32
40
50
50
Meter
Ends
3/4" BSPP
1" BSPP
1 1/4" BSPP
1 1/2" BSPP
2" BSPP
2 1/2" BSPP
50mm PN16
Union
Tails
1/2" BSPM
3/4" BSPM
1" BSPM
1 1/4" BSPM
1 1/2" BSPM
2" BSPM
Flanged
A
145
190
260
260
300
300
300
B
105
106
115
115
148
173
172
Dimensions (mm)
C
36
40
40
40
63
82
82
øD
15
20
25
32
40
50
50
E
100
100
104
105
125
126
165
Weight
(kg)
1.6
1.8
2.7
2.9
6.0
8.5
11.5
Woltmann Type Water Meters
Woltmann Type Water Meters
Max. Pressure Loss Diagrams
1
0.5
pressure loss (bar)
• Sizes 50-200mm
• Surpasses accuracy requirements of
75/33/EEC Class B
• Epoxy powder coated brass bodies
• Security via tamper evident wire lock
and seal
• Maximum temperatures:
Cold water meters: +30ºC
Hot water meters: +90ºC
• Maximum working pressure: 16 bar
• All major components are recyclable
• Large, easy to read dial with
protective cover
• Flange to EN1092-2 PN16
• Pulse output included
50
size - calibre (mm)
65
125 80/100
200
300
0.3
0.2
0.1
0.05
0.01
10
0.1
20
30
40 50
size - calibre (mm)
80 100 120
flow rate (m³/h)
150
500
200
pressure loss (bar)
0.05
0.01
0.005
5
0.001
30
50
100
200 300
500
1000
2000
4000
8000
flow rate (m³/h)
Woltmann Type Hot Water Meter
Performance Data
Cat No.
Cold
Hot
171260
171280
171261
171281
171262
171282
171263
171283
171264
171284
171265
171285
171266
171286
Size DN
(mm)
50
65
80
100
125
150
200
Qmin
m3/h
0.45
0.75
1.2
1.8
3.0
4.5
7.5
Qt
m3/h
3
5
8
12
20
30
50
Qn
m3/h
15
25
40
60
100
150
250
Qmax
m3/h
30
50
80
120
200
300
500
Litres per
Pulse
100
100
100
100
1000
1000
1000
B
øD
A
Dimensions
Cat No.
Cold
171260
171261
171262
171263
171264
171265
171266
Hot
171280
171281
171282
171283
171284
171285
171286
Cat No.
Flange Pack
T83148
T83149
T83150
T83151
T83152
T83153
T83154
Size DN
(mm)
50
65
80
100
125
150
200
Flange pack contains WRAS approved EPDM gaskets, BZP nuts, bolts and washers.
A
200
200
225
250
250
300
350
Dimensions (mm)
B
225
242
255
265
275
325
352
øD
50
65
80
100
125
150
200
Weight
(kg)
12.5
14
16
19
20
35
52
Multi-Jet Water Meter Registers
• Registers are dry dial type
• Hermetic sealing ensures that the consumption display remains clearly legible
• Register rotates through 360º for ease of reading
• Pulse emitting device for connection to BMS system, remote reader or other device.
If not required, pulse devices may be removed simply by undoing the retaining cover
screw
• Black rollers display cubic metres (m3). Red rollers display decimal fractions of cubic
metres. Water meters up to 32mm have five black and three red rollers. 40mm and
50mm water meters have six black and two red rollers. Low flow pointers display tenths
of litres on 15mm to 32mm meters and litres on 40mm and 50mm
• The sensitivity index rotates when there is ultra low flow that is insufficient to register
• Indicating range 0 to 99999.99 m3
Reed Switch Cover Screw
6
Reed Switch
5 x Black Rollers (m3)
Sensitivity Index
ISO/EC Class
Serial Number
note: 1m3 = 1,000 litres
Registers
3 x Red Rollers
(m3 x 0.001)
Low Flow Pointer
(m3 x 0.0001)
Registers
Woltmann Type Water Meter Registers
• Registers are dry dial type
• Hermetic sealing ensures that the consumption display remains clearly legible
• Pulse emitting device for connection to BMS system, remote reader or other device.
If not required, pulse devices may be cut off or tied back
• On 50mm to 125mm, six black rollers display cubic metres (m3). Low flow pointer
displays tenths of cubic metres. Very low flow pointer displays hundredths of cubic
metres. On 150mm to 200mm, six black rollers display tens of cubic metres (m3x10).
Low flow pointer displays cubic metres (m3). Very low flow pointer displays tenths of
cubic metres
• The sensitivity index rotates when there is ultra low flow that is insufficient to register
7
6 x Black Rollers (m3)
ISO/EC Class
Sensitivity Index
Low Flow Pointer
(m3 x 0.1)
Very Low
Flow Pointer
(m3 x 0.01)
Serial Number
note: 1m3 = 1,000 litres
Pipe Center is the specialist supplier of
commercial heating plant and pipe systems.
Branches offer a range of products including
boilers, water heaters, radiators, pumps
and commercial showers.
Pipe Center also stock the widest ranges of
pipes, fittings and valves in:
• Carbon steel • Pressure plastics
Typical Applications
• Copper
• Stainless steel
• Brass
• Bronze
Branch locations
Water meters can be used as an integral part of a heating system, both
to monitor the usage of hot water and to supply heat meters with the
flow rates of hot water used, so that energy consumption may be
calculated. The following applications are also relevant.
• Sub-Metering
• Dosing Systems
• Heating and Cooling Applications
• Industrial and Process Applications
for a list of the branch locations please visit:
www.pipecenter.co.uk
For further information about Jet range products, please visit
www.jetrange.co.uk
0870 8506538
or contact
Some products also available from:
www.plumbcenter.co.uk
www.partscenter.co.uk
www.draincenter.co.uk
Whilst every care has been taken to ensure that the information
included in this document was accurate at the time of printing,
we reserve the right to change specifications at any time. The
photographs reproduced in this publication are within the
constraints of the printing process and are NOT to be used for
matching purposes. E&OE.
Catalogue No. Y98043
ref:2877