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Resumen del manual
These requirements override the information given in Frame 3 if the static head required for the pump(s) exceeds that required for the boiler. MINIMUM FLOW OF WATER - Refer to Table 4 The system design must provide for an adequate flow rate through the boiler at all times when the boiler is firing. The minimum flow rate should correspond to a temperature difference across the boiler flow and return of 35°C (63°F), assessed at catalogue rating. Table 4 - Flow rates for fully pumped systems Boiler Minimum flow rates for a temperature difference of 35°C (63°F) l/s g.p.m. CXSi 110/H 0.75 9.9 CXSi 120/H 0.82 10.8 CXSi 140/H 0.96 12.7 CXSi 160/H 1.10 14.6 CXSi 180/H 1.24 16.4 HEATING BOILERS There is a basic need to treat the water contained in all heating and indirect water systems, particularly open vented systems. It is assumed, incorrectly, that because boilers are operating in conjunction with what is apparently a closed circuit an open vented system will not, under normal circumstances, allow damage or loss of efficiency due to hardness salts and corrosion once the initial charge of water has been heated up a few times. 1mm of lime reduces the heat transfer from metal to water by 10%. In practice the deposition of these salts is liable to cause noises from the boiler body or even premature boiler failure. Corrosion and the formation of black iron oxide sludge will ultimately result in premature radiator failure. Open vented systems are not completely sealed from the atmosphere if proper venting and expansion of system water is to be achieved. The same tank is used to fill the system with water and it is through the cold feed pipe that system water expands into the tank when the boiler passes heat into the system. Conversely, when the system cools, water previously expanded is drawn back from the tank into the system, together with a quantity of dissolved oxygen. Even if leakage from the heating and hot water system is eliminated there will be evaporation losses from the surface of the tank which, depending upon ambient temperature, may be high enough to 7Concord CXSi/H -Installation & Servicing Note. This diagram does not show safety valves, water flow switches, etc., necessary for the safe operation of the system. 3 OPEN VENTED SYSTEMS - minimum static head requirements Particular reference should be made to BS. 6644: Section 2; Subsection 10 and Guidance note PM5 "Automatically controlled steam and hot water boilers" published by the Health and Safety Executive. The information and guidance given below is not intended to override any requirements of either of the above publications or the requirements of the local authority, gas or water undertakings. Other British Standards applicable are BS.5422 and BS.6700. The information provided is based on the following assumptions: 1. The open vent MUST be brought to either the 1 1/2" BSP tapping on the flow header provided or to the unused 2" BSP flow tapping at the top rear of the boiler. 2. An independent cold feed/expansion pipe connection is made to the LH lower front connection. Cold feed/expansion pipe connections made to the pumped system return will result in an increase in the static head requirement, caused by the additional resistance of the distributor tube. Surging may also increase. 3. The maximum flow rate through the boiler is based on a temperature difference of 11°C at full boiler output and the circulating pump is positioned in the flow to the system. 4. The boiler is at the highest point of circulation in the system. Systems designed to rise above the boiler flow tappings will automatically require a minimum static head higher than that shown. 5. The position of the open vent/safety pipe above the expansion cistern water level is given as a guide only. The final position will depend upon the particular characteristics of the system. Pumping over of water into the expansion cistern must be avoided. GENERAL evaporate a large portion of the system water capacity over a full heating season. There will always be corrosion within a heating or hot water system to a greater or lesser degree, irrespective of water characteristics, unless the initial fill water from the mains is treated. Even the water in closed systems will promote corrosion unless treated. For the reason stated Caradon Ideal Limited strongly recommend that when necessary the system is thoroughly cleaned, prior to the use of stable inhibitor, which does not require continual topping up to combat the effects of hardness salts and corrosion on the heat exchangers of the boiler and associated systems. Caradon Ideal Limited advise contact directly with specialists on water treatment such as: Fernox Manufacturing Co. Ltd., Tandem House, Marlowe Way Croydon. Surrey CRO 4XS Tel 0870 601 5000 or Sentinel Division, Betz Dearborn Ltd., Widnes, Cheshire, WA8 8UD Tel. 0151 424 5351. SAFE HANDLING OF SUBSTANCES Care should be taken when handling the boiler insulation panels, which can cause irritat...
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Calentadores de Agua - Concord H CXSi 180/H (3.37 mb)