Modulating level controls - Filter

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6 LP20 probe and PA20 preamplifier The LP20 probe consists of a stainless steel rod completely insulated from the water by PTFE. As the water level rises the capacitance between the rod and the earthed boiler protection tube or probe chamber increases. The capacitance is measured by the preamplifier and is transmitted as a dc signal to the controller. Control and alarm levels are set in the controller. The probe, which must not be cut, is available in the following lengths (dimension L): 370, 470, 600, 750, 900, 1 050, 1 200, 1 350 and 1 500 mm. It is suitable for boiler pressures up to 32 bar g. LC2200 controller and LC2300 controller Proportional level controllers LC2200 For electrically actuated valves LC2300 For pneumatically actuated valves Features include:- Adjustable set point Adjustable proportional band Adjustable high or low level alarm (LC2200 only) Multi-voltage selection:- 230 V (198 - 264 V) or 115 V (99 - 121 V) 50 - 60 Hz Plug-in design with DIN rail clip Has a dc power supply and is able to accept a current input (4 - 20 mA) enabling it to power and be used with a two wire 4 - 20 mA transmitter (e.g. pressure, differential pressure, temperature). In-built valve positioner. (LC2200 only) Several controllers can be connected to a single probe or 4 - 20 mA source if required. Three stage level wave filter (input signal damping) to maintain a stable signal under varying turbulence conditions. 'Out of range' alarm provides a degree of self checking on damage to probe or wiring (LC2200 only). Controllers may be mounted on a 'top hat' DIN rail using the mounting clip provided or the controller base may be screwed directly to a chassis plate. System components Dimensions (approximate) in millimetres 52 52 Weight 0.5 kg Depth 120 LC2200 Weight 0.5 kg Depth 120 LT2010 112 112 145 162 L 8 DS1000 27 A/F ½" BSP taper Ø 12 25 mm dead length 52 Weight 0.5 kg Depth 120 LC2300 96 70 93 112 Remote transmission Where a remote signal representing water level is required (4 - 20 mA isolated signal) an LT2010 can also be connected to the level probe. The transmitter range can be set, for example, to represent the boiler level gauge glass. It can of course, be set to represent any range of levels along the probe. The transmitter output can be used to provide information to a management system or connected to a remote display unit such as the DS1000. 48 Panel cutout 92 x 44 Weight 200 g
Control valves Traditionally most larger shell boilers are supplied with a DN40 valve. The DN40 valve is available with a range of reduced seats to match the feedrate. Alternatively, and particularly for new boiler plant, a smaller valve can be specified. See separate Spirax Sarco literature for valve dimensions and selection information. Electric actuators must include a 1 000 ohm feedback potentiometer. Pneumatic actuators must include a positioner (E to P). Steel enclosure with chassis plate and two DIN rails for mounting two or three level controllers plus terminals. 400 300 Electrically actuated control valve with feedback potentiometer Recommended ancillaries Enclosures Probe chamber Plastic enclosure with DIN mounting rail. For a single controller. IP67 rating. Sequencing purge valve Type SPV1 with cast iron body, flanged BS 4504 PN16, DN25 for boiler pressures up to 13 bar g. Type SPV3 with bronze body flanged BS 4504 PN40, DN25 or BS 10 table F/H, 1" for boiler pressures up to 25 bar g. 83 205 deep 83 288 175 125 150 deep ½" BSP drain Steel probe chamber flanged BS 4504 PN40, DN25. For maximum boiler pressure of 32 bar g. 1" BSP (Reducing bush required for LP20) Pneumatically actuated control valve with positioner Disc check valve Type DCV2/B for fitting between control valve and boiler to prevent return flow. Will also ensure that feedtank will not drain into boiler when boiler is depressurised. See separate literature for full details. 83 65 457 7
Page 1 and 2: Modulating level controls for steam
Page 3 and 4: On-off level controls The water lev
Page 5: Adjustable transmitter range (typic

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