| 1 | Supply, Installation and Commissioning of 600 mm Electronically Modulated flow control valve will be controlled by an electronic-controller, which enables control of the requested flow rate or pressure as per demand. The controller should enable receive as an input either pulse/volume contact-input or 4-20mA analogue signal. The flow/pressure set-value may be modified automatically on time basis, or by a predefined relation to pressure or another measured parameter. The losses in flow control valve shall not be more than 0.2 kg/ cm2 for present as well as ultimate demand. The valve shall be hydraulically operated, single chamber, direct diaphragm-sealing valve. The valve shall consist of three major components: the body, cover and the diaphragm. In Weir Patten valves, a diaphragm and a spring are the only moving parts, and the diaphragm itself is the component that closes or opens the liquid flow. The diaphragm shall form a sealed chamber in the upper portion of the valve, separating operating pressure from line pressure. Packing glands and/or stuffing boxes are not permitted and there shall be no O-ring or similar seals on the shafts that may suffer friction which can start internal leakage in the valve. The valves should be capable of regulating at very low flow, No hourglass-shaped disc retainêrs shall be permitted and no V-type, U-type or other slotted type disc guides shall be used. The valve shall contain a resilient, nylon reinforced rubber diaphragm. The ratio between valve flow capacity (KV) and the valve position shall be linear so to allow stable regulation even under high pressure differentials and low-flow conditions. Disassembly and reassembly of all the valve's components shall be made possible on site, without having to remove the valve from the line. Each valve should be hydrostatically tested at least 60% above the rated pressure. A test report should be supplied with each valve. Body: Ductile iron ASTM A536 (Valve should be WRAS approved). Circuit Fitting: Brass EN12164, Surface Protection: Epoxy coating min. 150 microns, colour RAL 5005 Blue, Polyester coating min.100microns, colour RAL 5005 Blue, Operation: Automatic, manual override enabled, Nut Bolts and Studs: Stainless Steel AISI-304 ASTM-A 193 B7, Solenoid Valve (IP 68): Brass/SST 316. The pressure losses inflicted by the above mentioned fully opened valve should not exceed 0.3 bar at nominal flow speed of 3 m/sec. The minimal required pressure differential for reliable closure of the valve should not exceed 0,1 bar. Electronic Controller and trim - A specialized controller, designed for the control of hydraulic control valves. Setup, override-control and monitoring is enabled from the street-level (when installed in a valve-chamber), using an application on any android device and short-distance Bluetooth communication, Control over the valve via two continuous operation, 2/2 solenoid-valves and or two latching type solenoid valves. This configuration enables both high regulation-accuracy as well as energy-efficient operation. Enables selection of the solenoid valves' types: normally-open and or normally-closed. Controller must be IP65 protection. The controller electronics, including battery, antennas and Connection rail are packaged in an armoured and corrosion-resistant casing. The controller shall be supplied with a 12 VDC rechargeable battery that enables the controller's operation even through power-outage that may last a few days. The controller shall optionally be supplied with a charging unit supplied by local grid power, solar panel or water-driven dynamo. The controller shall have at least 4 analogue inputs (4-20mA). The controller shall have at least 6 digital inputs, including high-speed pulse type (for water-meter and flow-meter connection). Each of the inputs (both analogue and digital) can be used for remote actuation (enabled by programming): 'Start', 'Stop', 'Keep', 'Open' (full, uncontrolled opening) and 'Close' (full closure). The same functionality can be achieved via remote control communication (using R-Modbus protocol). The controller would have an extra two (2) configurable output relay contacts auxiliary device actuation (by-pass valve, pump etc.) and to be used as alarm contact in case of failure. All the wiring is done to a connections-terminal within the controller's casing via isolated and grounded cables. Software requirements: All the control functions, can be configured locally. Any control function is user-configurable and\or pre-configurable by the supplier. These functions include but are not limited to: 'Pressure-Reducing', 'Pressure-Sustaining', 'Flow control', 'Water-Level control', 'Pressure-Relief' etc. Combination of two or more of this control function is possible without any restriction, as long as this combination is not logically-contradicting and sufficient number of inputs is free. The controller will enable the control of any value, including non-hydraulic values (such as temperature, electric conductivity etc.) The user is able to allocate control inputs and outputs, per the used control-functions. The controller should allow the valve to operate in percentage opening and timer based automatic operation. Each input can be used for one or more control functions. Each analogue input's value, shall be converted and displayed with a user-defined display-units and per the measurement range of each sensor or control signal's source. The user can select the valve status to be fully open, closed or keep last position, on 'Stop' command and in case of hardware failure (low-battery, loss of sensor signal as well as customer defined failures). Actions such as fully open or close the valve by digital inputs, analogue input set-level, time, or remote communication are configurable by the user. Dynamic set-value modulation: Set-values are modifiable via remote communication or an analogue signal. In case of disconnected control-signal, the controller will continue to regulate per pre-set internal values. Set-values can be modulated to follow a change in another parameter in the system (example: change the reducing pressure according to flow changes). This, following to a pre-set profile. This pre-set profile can be set to be different for different days of the week, of the month or specific dates in the year. Set-values can be modulated according to the time of day and or days of the week, of the month or specific dates in a year. Set values will be fixed in case any of the above failure or are not configured or are disabled. Failure shall be defined as low-battery power with no charge power, disconnection of a sensor or shortcut or disconnected solenoid-valve. Other configurable failures can be deviation of a measured value, contact opening or closing etc. The operation of the valve in case of such failures will be user-defined as 'Keep last position', 'Open' (full, uncontrolled opening), 'Close' (full closure) or 'Continue regulating'. The valve should be properly encased in a chamber in such a way that further maintenance work will be easily feasible. Make: DOROT/ Any DJB Approved make. Please Enable Macros to View BoQ information |
