OPERATING AND MAINTENANCE MANUAL FOR VERTICAL IMMERSION HEATED STEAM BOILERS. Technical Control Systems Limited MODELS "VIHS"

Transcription

1 OPERATING AND MAINTENANCE MANUAL FOR VERTICAL IMMERSION HEATED STEAM BOILERS Technical Control Systems Limited MODELS "VIHS"

2 Technical Control Systems Ltd Treefield Industrial Estate Gildersome, Leeds LS27 7JU Phone Fax Internet -- IMPORTANT -- Always reference the full model number and serial number when calling the factory. WARNING / CAUTION 1. Mains water should be piped to the feed water 'break' tank, and the tank completely filled with water before energizing. 2. Due to the rigors of transportation, all connections should be checked for tightness before boiler is placed in operation. 3. Site pipework from the main valve on the boiler to the steam using equipment must be completed before putting the boiler in operation. 4. KEEP AWAY FROM LIVE ELECTRICAL CIRCUITS. Do not perform any maintenance, make any adjustments, or replace any components inside the control panel with the high voltage power supply turned on. Under certain circumstances, dangerous potentials may exist even when the power supply is off. To avoid casualties, always turn the power supply safety switch to off, before performing any maintenance or adjustment procedure. 5. Generalized instructions and procedures cannot anticipate all situations. For this reason, only qualified installers should perform the installation. A qualified installer is a person who has licensed training and a working knowledge of the applicable codes regulation, tools, equipment, and methods necessary for safe installation of a steam fired water heater. If questions regarding installation arise, check with your local plumbing and electrical inspectors for proper procedures and codes. If you cannot obtain the required information, contact the company. Page 2

3 TABLE OF CONTENTS SECTION TITLE PAGE I GENERAL DESCRIPTION AND CONSTRUCTION 4 II INSTALLATION AND OPERATION 6 III SCHEDULED MAINTENANCE AND SERVICING 8 IV TROUBLESHOOTING 9 Page 3

4 SECTION I - GENERAL DESCRIPTION AND CONSTRUCTION GENERAL DESCRIPTION This book describes a TCS packaged horizontal immersion heated steam boiler (HIHS), which is a stationary, self contained unit. The complete assembly on a standard unit consists of the pressure vessel, immersion heating elements, and a control panel built to IEC Optional equipment may be supplied with your unit. Please consult the product drawing for details specific to your assembly. The unit is factory assembled, insulated, jacketed, primed, painted, piped, tested, and ready for service connections. CONSTRUCTION PRESSURE VESSEL Standard Vessel Construction: The standard pressure vessel is constructed of all welded carbon steel, designed and built in accordance with BS5500 and stamped, certified, and registered with Lloyds. SERVICE CONNECTIONS The boiler is supplied with the following service connections WATER SUPPLY The feed water 'break' tank is situated to the side of the boiler and mains water should be piped to this tank which has B.S.P. connections as sized in the dimension list. An overflow connection is provided on this tank and this must be piped to a safe drainage point. STEAM OUTLET The steam outlet is fitted with a main valve which should be piped to the steam using equipment. STEAM SAFETY VALVE Ensure that the outlet connection of the valve is free from packing material, keep the outlet pipe as short as possible and ensure it is adequately supported, fit outlet pipework of equal or larger size then the valve outlet, direct the outlet pipework to a safe point, where the discharge is visible and there is no risk of injury to persons or damage to equipment if the valve operates, where the outlet pipework is directed upwards an open drain must be provided at it's lowest point. BLOWDOWN CONNECTIONS There are two blowdown valves on the boiler, the main valve at the rear of the boiler, and the water gauge glass blowdown valve. The outlet pipe from each blowdown valve must lead to a blowdown vessel or other safe discharge point OUTER SHELL, INSULATION, AND SUPPORTS The pressure vessel is encapsulated in 2-inches of high-density fiberglass insulation. The protective shell is constructed of galvanised steel and is coated with a durable blue hammertone finish. The entire vessel is supported on heavyduty integrally welded steel supports for sturdy floor mounting. Page 4

5 HEATING ELEMENTS The steam boiler is supplied with high quality factory installed heavy duty "Incoloy" sheathed elements of low watts density (11.6 W/cm²), arranged for multi-stage progressive load control, mounted with B.S.P. threaded ferrules to facilitate easy field replacement. Page 5

6 SECTION II INSTALLATION AND OPERATION WARNING / CAUTION The voltage of the mains and control system is high enough to endanger life, when the equipment is opened for inspection and testing, it will sometimes expose live parts. Work on live equipment is only to be undertaken by qualified personnel who are fully aware of the risks involved and who have taken precautions to avoid direct contact with dangerous voltages. So far as is possible low voltage equipment must be entirely disconnected and isolated from the system before any repairs or maintenance is commenced, and tests made to prove that the relevant equipment is completely dead. Positive safeguards should be employed to prevent the circuit from being inadvertently energised whilst work is in progress and a DANGER warning notice should always be displayed in the vicinity of exposed live connections. If the unit is painted or insulated on site, care should be taken not to paint or insulate over any nameplates. These plates should be accessible and legible at all times to inspectors, and information from the TCS rating plate must be used when ordering parts from the factory. BOILER SITING 1. Adequate space should be provided for removal of heating elements and in front of the control panel for electrical connections to be made safely. 2. Unit should be sited on a firm and level base to permit proper drainage. PIPING INSTALLATION Piping to the unit should be sized to meet the design conditions, as dictated by good engineering practices. CAUTION: No valve of any type should be installed in the safety valve pipework. ELECTRICAL CONNECTIONS Terminate the main supply cable on the control panel main isolator. Ensure that a full screw check for tightness is carried out before switch on, connections for main cables between both fuses and contactors, contactors and elements can become loose during transport and if so will overheat. It is also essential to remove shrouds from fuse carriers and check clamp connections to copper bars. These are tightened by means of an Allen Key or screw connection. Page 6

7 FILLING THE BOILER Begin with all water valves closed. Open the steam valve. Open cold water supply valve(if fitted), and fill tank with cold water. Open valve between the tank and the pump. Ensure all stage selector switches are in off position. Close main isolator and turn panel live on/off switch to on position. The extra low water level warning lamp(red) will illuminate and the feed pump should automatically start and run until water level in boiler reaches the correct level. While ever the pump is running, the pump running indicator light should be illuminated (green). If the water level in the feed tank does not drop then the pump requires bleeding. Loosen the bolt adjacent to the pump outlet until all the air is vented. CAUTION: During the initial filling of the pressure vessel the pump may deliver more water than can be replaced by the cold water feed. Do not operate pump without the tank being filled with water as damage to the pump could result. STARTUP Carry out the following procedure on the initial start up of the boiler and on every subsequent occasion when re-starting the boiler after a shutdown. 1. Open the steam valve. 2. Open all the valves in the water line to the top up tank and feed pump. 3. Open the water gauge valves. 4. Close the boiler and water gauge glass blowdown valves. 5. Switch on main power isolator. 6. Switch on the boiler control circuit and load stage switches. 7. The panel indicator lights will come on showing that the controls have been energised and the water feed pump will start and continue operating until the water in the boiler has reached the correct level. 8. Once the water in the boiler has reached the correct level the elements will automatically be energised and the load stage contactors will be heard to click in progressively. The steam pressure control will control the on-off cycle of the elements once the boiler is operating. The low water relay will immediately shut off the power to the elements should the water in the boiler drop to an unsafe level and will only re-energise the elements when the water has regained a safe level in the boiler. A red indication light is provided to give warning of this condition. SHUTDOWN Turn panel live selector switch to the off position. Open each blowdown valve for a few seconds to clear away accumulated sediment. Where untreated feed water is used, increased sediment inside the boiler should be removed by blowing down for a longer period. Page 7

8 SECTION III - SCHEDULED MAINTENANCE AND SERVICING WARNING / CAUTION Before performing any maintenance procedure, make certain boiler water supply and electrical power supply is OFF and cannot accidentally be turned on. WEEKLY INSPECTION 1. Make sure that the pipe from the safety valve outlet is not damaged and that it continues to a safe blow-off point. 2. With the boiler under pressure, lift test lever on safety valve and let steam discharge for a second or two. This proves the free operation of the safety valve. 3. Check the low water cut-out relay is operating correctly as follows: With the boiler switched on, but with little or no steam pressure, open the boiler blowdown valve allowing the water in the boiler to drop below the safe working level, at which point the elements should de-energise and an audible click heard as the contactors 'drop out'. The red warning light situated on the facia panel should indicate a low water condition. THREE MONTHLY 1. Check the elements for continuity and insulation. 2. Inspect the boiler for leaks and replace gaskets as necessary. 3. Clean and water gauge sight glass. If any leakage is evident renew the gasket. 4. Remove the strainer situated in the feedwater line between the tank and pump and clean thoroughly before replacing. 5. Remove copper pipework to pressure switch and pressure gauge and flush with water to clean out sediment. ANNUALLY 1. Drain and flush the feedwater tank. Clean any filters in the tank, in the feedwater line or the feedwater pump. 2. Remove the elements and clean off any scale build-up. 3. Inspect boiler shell for scale and lime and clean out. 4. Remove and clean the three water electrodes, taking care not to crack the porcelain. After replacement check the operation of the low water cut-off relay and of the water feed pump. 5. Check all control panel connections for tightness. 6. Check contactors for free action and clean contacts. Page 8

9 SECTION IV TROUBLESHOOTING (See separate component O&M for additional details.) Symptom Probable Cause Corrective Action / Remedy Gradual loss of heating capacity Gauge glass not showing correct level Element failure Blockage in pipe or gauge cock. Renew faulty elements Remove gauge cock and clean cock and pipe Pump overfills boiler Level probe failure Check connections and replace probe if necessary Boiler not filling with water or hot water returning to tank Check valve faulty Remove check valve and clean valve seat, or renew check valve. * Red symptom indicates that equipment should be shut down immediately and cause of malfunction corrected before unit is re-started or serious damage may result. Page 9