Flanged mechanical water meter for cold potable water on mains and bulk supply lines. The body photographed is cast with the size 100 and a flow arrow; flange drilling, Q3 and R must be stated when ordering.
Prices on request. Contact us for availability and quotations.
A flanged water meter is the same measuring instrument as a threaded one, carried in a body with bolted flanged ends so it can be lifted out of the line without disturbing the pipework. Above about DN50 that is the only practical arrangement, and it is why bulk supply, district and irrigation metering is almost always flanged.
The designation rules are the same as for any meter to ISO 4064-1:2014 / OIML R 49-1:2013: the meter is defined by its permanent flow rate Q3 in cubic metres per hour and the measuring ratio R = Q3/Q1, not by its nominal bore. Q2/Q1 is fixed at 1.6 and Q4/Q3 at 1.25. A class 2 meter is allowed ±5 % between Q1 and Q2 and ±2 % between Q2 and Q4 on water up to 30 °C; class 1 halves both figures. Maximum admissible pressure is at least 1 MPa (10 bar), and the standard pressure loss class is Delta p 63, meaning no more than 0.63 bar lost between Q1 and Q3.
The flange drilling is the specification that decides whether the meter can be installed at all. EN 1092-1, quoted as PN 10, PN 16, PN 25 or PN 40, and ASME B16.5, quoted as Class 150 or Class 300, differ in bolt circle diameter, bolt count and hole size; a DN100 meter drilled to EN 1092-1 PN16 will not bolt to a 4 inch ASME Class 150 counterflange. Confirm the standard, the rating and the face type against the existing pipework before ordering, and confirm the face-to-face length, which is not fixed by the metering standard.
When ordering, state the nominal bore, flange standard, rating and face type, Q3 and R, temperature class, pressure loss class, mounting orientation, and whether a pulse output or remote reading head is required. For a billed or custody-transfer duty ask which type approval the meter holds.
| Standard | ISO 4064-1:2014 / OIML R 49-1:2013, water meters for cold potable water and hot water |
|---|---|
| Designation | By permanent flow rate Q3 in m3/h with the measuring ratio R = Q3/Q1. Q3 is chosen from 1; 1.6; 2.5; 4; 6.3; 10; 16; 25; 40; 63; 100; 160; 250; 400; 630; 1000; 1600; 2500; 4000; 6300 m3/h, a list the standard allows to be extended to higher or lower values, and R from 40; 50; 63; 80; 100; 125; 160; 200; 250; 315; 400; 500; 630; 800; 1000, extendable to higher values |
| Accuracy (MPE) | Accuracy class 2: ±5 % from Q1 to Q2, and ±2 % from Q2 to Q4 for water 0.1 to 30 °C, ±3 % above 30 °C. Accuracy class 1: ±3 % from Q1 to Q2, and ±1 % from Q2 to Q4 for water 0.1 to 30 °C, ±2 % above 30 °C |
| Flow Rate Ratios | Q2/Q1 = 1.6 and Q4/Q3 = 1.25, both fixed by the standard |
| Temperature Class | T30 (0.1 to 30 °C) unless the meter is marked otherwise. Also defined: T50, T70, T90, T130, T180 and the ranges T30/70, T30/90, T30/130, T30/180 |
| Maximum Admissible Pressure (MAP) | At least 1 MPa (10 bar); at least 0.6 MPa (6 bar) for DN 500 and above. MAP is marked on the meter only where it exceeds those values |
| Working Pressure Range | 0.03 MPa (0.3 bar) to at least 1 MPa (10 bar) |
| Pressure Loss Class | Delta p 63, i.e. not more than 0.063 MPa (0.63 bar) between Q1 and Q3, unless marked otherwise. Also defined: Delta p 40 (0.40 bar), Delta p 25 (0.25 bar), Delta p 16 (0.16 bar) and Delta p 10 (0.10 bar) |
| Static Pressure Withstand | 1.6 x MAP for 15 min and 2 x MAP for 1 min, without leakage or damage |
| Connection | Flanged |
| Flange Drilling | To be specified. EN 1092-1 (PN 10 / 16 / 25 / 40) and ASME B16.5 (Class 150 / 300) differ in bolt circle, bolt count and hole size and will not mate at the same nominal size |
| Nominal Size, Unit Photographed | 100, cast on the body beside the flow arrow |
| Marking Required | Unit of measurement; Q3 and R; accuracy class only where it differs from class 2; type approval sign; maker's name or trademark; year of manufacture; serial number; flow-direction arrow; temperature class where not T30; pressure loss class where not Delta p 63 |
