metering station flow data - flocontrol ltd | picv, abv, … · 2016-01-06 · double regulating...

Metering StationFlow Data

Sizes DN65 to 600

In this flow data manual we have endeavoured to make the information as accurate as possible.We cannot accept any responsibility should it be found that in any respect the information is inaccurate or incomplete or becomes so as aresult of further developments or otherwise.

Stainless Steel Metering StationTechnical Data

FloControl Limited Tel: 01282 564425Ribble Court, No. 1 Meadway Fax: 01282 564426Shuttleworth Business Park, Padiham email: sales@flocontrol.ltd.ukBurnley, Lancashire BB12 7NG website: www.flocontrol.ltd.uk© FloControl Limited 2014

Flow Measurement The flow rate can be calculated using the Kvs value and a measured signal.

Kv = Q Kvs = Q √∅P √∅Ps where Kv & Kvs = flow coefficient (m3/hr at 1 bar differential) Q = flow rate (m3/hr) ∅P = headloss attributable to valve (bar) ∅Ps = differential pressure across tappings (signal) (bar)Kvs Values

Pressure Loss The pressure loss across the metering station can be determined by multiplying the signal by the pressure loss factor. The pressure loss is always less than measured signal.

Pressure Loss Factors

Size DN65 DN80 DN100 DN125 DN150 DN200 DN250 DN300

Kvs 100.7 133.8 237.7 339 511 858 1235 1793

Size DN65 DN80 DN100 DN125 DN150 DN200 DN250 DN300

Factor 0.40 0.40 0.35 0.35 0.35 0.35 0.35 0.35

Size DN350 DN400 DN450 DN500 DN600

Kvs 2260 2961 3741 4789 6866

Size DN350 DN400 DN450 DN500 DN600

Factor 0.35 0.35 0.35 0.35 0.35

Stainless Steel Metering StationTechnical Data

FloControl Limited Tel: 01282 564425Ribble Court, No. 1 Meadway Fax: 01282 564426Shuttleworth Business Park, Padiham email: sales@flocontrol.ltd.ukBurnley, Lancashire BB12 7NG website: www.flocontrol.ltd.uk© FloControl Limited 2014

Installation Metering stations can be installed in isolation or close coupled to an oblique globe double regulating valve complying to BS 7350, of the same nominal diameter. Regardless of installation there must always be a minimum of 5 pipe diameters of straight pipe, without intrusion, upstream of the metering station. When used in isolation a minimum of 2 pipe diameters of straight pipe are required downstream of the metering station. When close coupled to an oblique double regulating valve no straight pipe is required after the valve. When used in conjunction with a butterfly double regulating valve, a spool piece equivalent to a minimum of 2 pipe diameters is required between the metering station and butterfly valve. For more detailed instructions please refer to the Installation, Operation and Maintenance Instructions supplied with the metering station.

ß Ratio The ß ratio is the ratio between the pipe bore and the orifice diameter. This range of metering stations has been designed using ß ratios selected to minimise the effects of variations in pipe bores.

Sizing Once the required flow rate has been calculated, the size of the metering station can be determined based on the following: The minimum signal at the design flow rate of 1 kPa. For minimum pressure loss, a maximum signal of 4.5 kPa, which corresponds to the maximum differential pressure range of a flurocarbon manometer. The recommended maximum flow velocity is 3 m/s, although for sizes up to and including DN150 a 2 m/s maximum velocity is recommended to minimise water noise.

5D 2D5D 5D3D

Stainless Steel Metering StationDN65

Graph of Signal against Flow Rate.Velocity based on the inside diameter of BS EN 10255 Medium series pipe

1.5 2.0 3.0 4.0 5.0 6.0 8.0 10 15 FLOWRATE - l/s

VELOCITY - m/s0.5 0.75 1.0 1.5 2.0 2.5 3.0

Issue 1 DN65 Metering Station

Flow Coefficient Kvs = 100.7

Pressure Loss Factor = 0.40

2.0 3.0 4.0 5.0 6.0 8.0 10 20 FLOWRATE - l/s