FULTON VMP Series - Draining the Boiler for Maintenance

VMP-IOMM-2018-2
Fulton Ltd
Page 34
OPERATION - 4
4.2.1 BOILER CONTROLS
Note: All the limiters are of the ‘fail-safe’ type and are wired in series; failure of any one will automatically shut
down the boiler.
Low Water Limiters, Feedwater Pump Relay and High Water Level Relay
These limiters and relays operate in conjunction with probes suspended in the boiler and water
bottle to automatically maintain the level of water in the boiler and to cut off the burner should the
water level fall to an unsafe level.
Steam Pressure Controls
The steam pressure controls vary depending on the type of boiler control utilised. The controls
are located on the side of the control panel box and are connected to the steam pressure gauge
assembly by copper tube. An operating pressure switch controls the on/off cycle of the burner,
shutting the burner off when maximum operating pressure is reached and switching it on when
thesteampressurefalls.AHigh/Lowpressureswitchmaybettedwhichswitchestheburner
betweenahighameandalowamewhichallowstheburnertocontinuouslyrunratherthan
switching it on & off. An operating pressure transducer replaces the operating pressure switch for
a modulating control.
Note: A set-back pressure controller is tted when multi-boilers are tted with a sequence control.
Burner Programmer
This is the main control in the panel box. The programmer in conjunction with a sensing device
‘supervises’theignitionsequence,provestheameissatisfactoryandnally‘monitors’the
establishedame.Shouldanyfaultoccur,eitherduringtheignitionsequenceorduringnormal
running, the programmer will immediately go to ‘lockout’ and the Multi-bloc gas valve will be
closed.
Air Pressure Switch
Mounted on the burner scroll, this switch is operated by the pressure of air entering the burner
throughthethroatofthescroll.Lackofair,orinsufcientpressure,willpreventtheswitch
completing the circuit thus preventing the burner from operating.
Gas Head Assembly
Consists of a Multi-bloc incorporating an integral governor, pressure switch and gas valves or
for larger boilers in addition to the internal components, an external pilot line with its own gas
solenoidvalvesandgovernor.Forboilersttedwithfullymodulatingburners,agasactuatoris
ttedtothegastrain.
Fuel Pump (OIL)
Mounted on the burner scroll and driven by the burner motor, the fuel pump delivers oil to the
burner nozzles at the correct pressure to allow complete atomisation and therefore combustion.
Note: Boilers tted on skid systems and in plantrooms are interlocked with the feedwater and condensate return
tank, after switching the boiler on at the boiler control box isolator switch, the reset button on the tank control box
must be reset. This reset must also be selected after any electrical outage.