The main activities of water flow laboratory include calibration and testing of flow products in water. Products covered includes all types of flow meters, valves, water meters, pumps, water conveyance pipe and fire fighting equipments.
The water Flow laboratory works on the gravimetric Static Weighing Method. This method is as per ISO 4185 and here the flow meter is calibrated to the highest accuracy by weighing the quantity of water that passes through the meter during a known time interval. The laboratory is designed to handle a maximum flow rate of 4500 m3/h and a maximum pressure of 10 bar. Pipes upto 900 mm NB diameter can be accommodated in the system.
The test rig has different test lines sizes up to 900 mm NB and the laboratory is capable of extending the line size upto 1200 mm. A large underground sump of 370 m3 capacity is used to store the required water. The test rig is supplied with water at constant head from an over head tank of 50 m3 capacity and 18 m head. During operation the constant head tank (CHT) is continuously overflowed using different low pressure pumps, which can be selected according to the requirement of the test meter. Weighing tanks of capacities 30 kg, 300 kg, 2000 kg and 20000 kg are made available for the flow measurement. Diverter systems are used to divert the flow to the weighing tank for an accurately measured time period (flying start and stop method). The mass measurement is by high precision electronic balance/load cell. Time is measured using universal counter which is triggered by a photo switch connected to the diverter system. A set of high precision differential pressure transmitters are available for the measurement of pressure drop. Resistance temperature detectors are used to measure the water temperature. The density of water at flowing condition is measured using an online density meter. Together with measurement of density at the moment of each diversion enables mass readings, after correction for buoyancy, to be converted into volume. The volume is divided by the respective diversion time to obtain accurate measurement of flow rate.
The laboratory has been accredited by National Accreditation Board for Testing and Calibration Laboratories (NABL) and also has ISO 9001 certification..
100 MM Water Flow laboratory
Considering the requirement of a high accuracy (± 0.1%) set-up for calibrating new generation flow meters and the heavy demand in the existing Water Flow Laboratory, especially for sizes upto 100 mm, an advanced high accuracy water flow laboratory to accommodate meter sizes upto 100 mm, a maximum flow rate of 250 m3/hr and a maximum pressure of 3 bar has been set up and commissioned in the month of October 2005. The laboratory is accredited by NABL for testing and calibration and by W&M for model approval of flowmeters.
Establishment of transfer standard flow measurement facilities
The essence of this project is to assist Department of legal metrology in setting up a secondary flow measurement facility. The project is expected to assist process industries, state water boards, oil sector, thermal power plants, fertilizer, petro chemical Industries etc.The maximum flow rate achieved is 250m3/hr at 40m head. The facility was designed on the basis of transfer standard, which is to be traceable to FCRI.
In principle, the transfer standard is proved against the static gravimetric system of FCRI. The transfer standard of measurement is designed to achieve accuracy better than +/- 0.2% in volume flow rate.The maximum flow rate required for testing 100mm NB meter is estimated to be 250 m3/hr. This can be achieved by the flow from pumps running in combination.
Intercomparison between FCRI and NEL, United Kingdom
In this inter-laboratory comparison program, the gravimetric water flow measurement facility of FCRI was compared with the gravimetric flow measurement facility of TUV NEL Ltd., UK. An eight inch NB orifice plate assembly was used to compare the performance of the flow measurement standards. The discharge-coefficient (Cd) of the orifice plate assembly in the Reynolds number range of 3.4 × 105 to 1.2 × 106 was determined by FCRI India and TUV NEL UK. Since it is the requirement of ISO 17025 accreditation En Numbers were estimated for the mean cd at each Reynolds number and it was observed that the En numbers were less than one in all cases. Hence it has been proved that the FCRI results are well comparable with International systems and the system reproducibility over a period of time is good.
Special Testing/Calibration Carried out
a. Dual flow Dispenser Valves
Three Duel flow dispenser valves of size 15mm NB from M/s. Parker Hannifin India Pvt. Ltd., Mumbai was tested. Flow test and response time test were tested as described below.
Water Flow Test:
The discharge through the valve at various upstream pressures was observed. Pressure tapping was given at an upstream distance of 2D from the valve.
Response Time Test:
The current sensor output was interfaced to a high speed DAS system and data are captured on a computer at desired sampling speed. The output from a high response line- static pressure transducer and a flow meter are also interfaced to the DAS. During test, for a set operating condition for pressure, the valve under test (VUT) is operated from OPEN to CLOSE (low flow to close). The current, pressure and flow are monitored on DAS during the process.
The instance of valve closure signal by electrical actuation (ie switching off power to VUT) is known from the current transducer signal (refer Fig 1 Instance
When VUT proceeds to clos