low rate metering device 683 series CCRI 040/ GB ISO 900 M 64 ISO 900 No. 0003 unction he flow rate metering device is used to measure the flow rate within a circuit. When used for central heating purposes, therefore, it allows monitoring of the thermal power supplied to the systems; in water treatment systems and industrial chemical or textile plants etc., it can be used to continuously monitor the water flowing through the circuits. his particular series of devices is equipped with quick-fit ports for easier differential pressure measurement. Product range 683 series low rate metering device, threaded connections sizes 3/4 and 683 series low rate metering device, flanged connections, to be coupled with counterflanges PN 6 sizes N 3 N 683 series low rate metering device, flanged connections, to be coupled with counterflanges PN 6 sizes N N 00 echnical specifications Materials Body: Gaskets: Screws: Nuts: Pressure test ports: Pressure test port seals: series 683 threaded 683 flanged brass N 6 CW67N - - - brass N 64 CW64N PM painted steel asbestos free NBR fibre steel steel brass N 64 CW64N PM Performance Medium: Max. percentage of glycol: Max. working pressure: Working temperature range: Minimum for measurement: Connections Main: Pressure test ports: water, glycol solutions % bar - C 0,0 bar 3/4, /4 water, glycol solutions % 6 bar (N 3 N ), 6 bar (N N 00) - C 0,0 bar counterflange N 9- PN 6 (N 3 N ) counterflange N 9- PN 6 (N N 00) /4
imensions B C B C 68300 683006 3/4" " B 3 9 C 3 3 4 78 90 Mass(kg) 0,30 0,43 683030 683040 6830 683060 683080 683 6830 683 68370 68300 N 3 40 6 80 7 00 C 64 7 88 40 8 7 80 8 74 77 83 90, 6 4 60 7 8 0 30 307 390 4 30 7 300 3 3 0 30 40 60 90 8 3 340 Mass(kg), 6,7 7,6,43 6,03 0,06 48,00 6,00 74,00 96,00 Operating principle he 683 series flow rate metering device operation is based on the Venturi effect. he metering device contains a diaphragm that, by restricting the cross-section of the channel, speeds up the medium and generates an increased (for measurement) at the ends, in order to guarantee precise flow rate metering. ach differential pressure value (measured at the ends of the diaphragm) has a corresponding accurate flow rate value, with the diaphragm Kv noted. he total head loss for the metering device is, however, very low since the length of the pipe downstream from the diaphragm allows the medium to slow down and increase the pressure again. (kpa) h 734 C) ) 'h α h = 'h sen α =,6 h )B) aria h (for mesurement) ) h (total head loss) ifferential pressure measurement he differential pressure can be measured using any pressure gauge or meter capable of operating within the range 0 kpa (0 0 mm w.g.; see adjacent figure). Whichever method or instrument is used, the air must be vented from the connection pipes to prevent errors when reading the differential pressure values. ) Caleffi LOM electronic measuring station (30 series) B) differential pressure gauges with dial C) inclined U-shaped pressure gauges with mercury column ) upturned U-shaped pressure gauges with water column ) a transparent plastic hose (resistant to the static pressure of the system), system water functioning as pressure gauge fluid, air trapped in the hose acting as a separator.
Construction details low rate monitoring can take place at any moment, without any of the pipes being dismantled. he patented self-cleaning single-casting diaphragm profile and the quick-fit pressure test ports offer rapid and accurate differential pressure measurement. Pressure measurement utomatic reclosure Safety cap Measuring syringe Seal element Hydraulic characteristics low rate measurement (l/s) G (m 3 /h) 0 Ø 3/4 N 3 N 40 N N 6 N 80 N N N N 7 N 00 { I.S. UNIS G =low rate in l/s = ifferential pressure in kpa water density (ρ) kg/dm 3 G= 0,9 0, G= 0,9 0, G= 0,337 0, G= 0,33 0, G= 0,989 0, G=,64 0, G=,438 0, G= 4,09 0, G= 9,03 0, G=,90 0, G=,806 0, G=,80 0, 0 3 0, 0,3 0, 0, 0 00 0 0, 0, 00 0 0 0 N 00 N 7 N N N N 80 N 6 N N 40 N 3 " 3/4" (mm w.g.) 0, (kpa) Kv coefficients, localised losses and equivalent lengths, head losses I.S. UNIS (kpa) (mm w.g.) 0 3/4" " N 3 N 40 N N 6 N 80 N N N N 7 N 00 Ø 3/4 N 3 N 40 N N 6 N 80 N N N N 7 N 00 Kv ( kpa) 0,4 0,73 0,403 0,637,8,978,94 4,93 3,90 9,44 40,8 8,3 G =low rate in l/s = ifferential pressure in kpa water density (ρ) kg/dm 3 ξ 3 7 7 6 6 0,7 0,9 0,7 le (m) 7 8 3 4 8 0 7 8 9 9 = f (G) = 4,8769 G = 3,3637 G = 6,79 G =,46 G = 0,73 G = 0,7 G = 0,78 G = 0,044 G = 0,00 G = 0,00 G = 0,6-3 G = 0,93-3 G 0, 0 0 00 0, 0, 0, 0, 0,3 0, 0 3 0 00 0 0 G (l/s) (m 3 /h)
Correction for liquids with different density he following notes apply to liquids with viscosity 3 (water and glycol mixtures, for example). If using liquids with a density different to that of water at 0 C (ρ = kg/dm 3 ), the head loss value measured may be corrected using the formula: = /ρ () where: = reference head loss = measured head loss ρ = liquid density in kg/dm 3 he value is used when measuring flow rate G, using the graphs or the formula (): G = Kv () xample of correction for liquid with different density Metering device N Liquid density ρ' =, kg/dm 3 Head loss measured on Venturi = 3 kpa Let us use formula (): Reference head loss = 3/, =,7 kpa his value is marked on the x-axis of the graph corresponding to the measured with the Venturi (green line); the point at which this value meets the line for the N metering device indicates the corresponding flow rate G = 7 l/s on the y-axis. Similarly, by using formula ():,7 G' = 408,96-3 = 6,64 l/s Sizing method he size of the metering device should be selected so that, when operating at the design flow rate, it has a corresponding minimum measured of mm w.g. ( kpa). Sometimes, to achieve this condition, it may be necessary to use a metering device with a diameter which is different to that of the pipe. In this case, a tapered fitting should be used (as illustrated in the figure below). min., d d Installation he metering device should be installed in the system during the initial setup phase, observing the flow direction indicated on its body and in accordance with the following instructions: - installation on the return pipe, in a position where it can be easily accessed for measurement purposes, with the pressure test ports facing upwards in order to prevent impurities from building up. he return water temperature has fewer variations, which increases measurement accuracy. - installation on a straight length of piping, either horizontally or vertically but not turned upside down, well away from twists or devices which may disrupt flow, particularly at the inlet, during measurement. In thermal installations, the metering device can be used in supply systems with several risers, branches or zones, to monitor the value of the individual flow rates or wherever metering of heating costs is required. he rapid flow rate monitoring keeps the system at optimal running conditions, making it possible to identify balancing variations caused by lockshield valves or other balancing and regulation devices, or by tampering. he application diagrams at the end of the brochure indicate the optimal points for flow rate monitoring: ) installation on the boiler circuit, ) installation on each riser, for system balancing monitoring, 3) installation on the horizontal sections of supply columns, as an alternative to point, 4) installation on each zone, for balancing throughout the system. d min., d ccessories Pair of fast-plug pressure/temperature test ports. heir special construction allows rapid and accurate measurements, guaranteeing a perfect hydraulic seal. Cap clamp available in the following colours: - Red for upstream pressure test port. - Green for downstream pressure test port. 0 Pair of fittings with fast-plug syringe for connection of pressure test ports to measuring instruments. emale /4 threaded connection. Max. working pressure: bar. Max. working temperature: C. Brass body. PM seals. emale /4 threaded connection. Working temperature range: - 30 C Max. working pressure: 30 bar. 30 LOM low rate and differential pressure electronic measuring station. Supplied complete with shut-off and connection fittings. Can be used for checking the correct operation of UOLOW devices. Measurement range: 0,0 00 kpa. ifferential Pmax: kpa. 000 30000 3000 Supply voltage 30 V (ac) Battery operated
max 0 C max C Pmax bar Pmax bar pplication diagrams Central heating system P Riser and zone systems Shut-off valve Zone valve xpansion vessel eaerator Ball valve Pump 3-way cock uel shut-off valve BLLSOP emperature gauge ifferential by-pass valve low switch Backflow preventer UOLOW irt separator emperature probe Safety thermostat emperature controller P Pressure switch Inspection pocket Gas filter Gas regulator Pressure reducing valve nti-vibration joint Pocket Safety valve Y-strainer
SPCIICION SUMMRY 683 series low rate metering device. hreaded connections 3/4 and. Brass body. Brass pressure test ports. PM pressure test port seals. hreaded connections /4 for pressure test ports. Medium water, glycol solutions. Maximum percentage of glycol %. Working temperature range - C. Maximum working pressure bar. Minimum for measurement 0,0 bar. Complete with quick-fit pressure test ports. 683 series low rate metering device. langed N 3 N 00 connections. Painted steel body. sbestos-free fibre NBR gaskets. Steel screws. Steel nuts. Brass pressure test ports. PM pressure test port seals. hreaded connections /4 for pressure test ports. langed connections. Coupling with counterflanges N 9- N 3 N, PN 6; N N 00, PN 6. Working temperature range - C. Maximum working pressure 6 bar (N 3 N ), 6 bar (N N 00). Minimum for measurement 0,0 bar. Complete with fast-plug pressure test ports, counterflanges, bolts and gaskets. 30 series LOM low rate and differential pressure electronic measuring station. Supplied complete with shut-off and connection fittings. It can be used to check UOLOW device operation falls within the working range. It can also be used to measure the flow rate of series 3 and 3 balancing valves, and of the 683 series metering device. Measurement range 0,0 00 kpa. Unit of measurement can be selected from Pa, kpa, mmw, mw, inw, mbar, PSI. Maximum line pressure 6 bar. Maximum differential pressure tolerated kpa. series Pair of fast-plug pressure and temperature test ports. threaded connections /4 M. Brass body. PM internal elements. Working temperature range - 30 C. Maximum working pressure 30 bar. series Pair of fittings with fast-plug syringe. hreaded connection /4. Maximum working temperature C. Maximum working pressure bar. We reserve the right to change our products and their relevant technical data, contained in this publication, at any time and without prior notice. S.p.. S.R.9, N. 80 ontaneto d gogna (NO) Italy el. +39 03 849 ax +39 03 86373 www.caleffi.com info@caleffi.com Copyright 0 Caleffi