Table 142 Problems and solutions the boiler and steam distribution system

System Component Problem

Initial Maintenance Action

Boiler

Steam trap Steam valve Steam line

Condensate return Condensate tank

Condensate pumps

Inoperable gauges Most recent boiler adjustment at least two years ago Scale deposits on water side of shutdown boiler Boiler stack temperature more than 150°F above steam or water temperature Fuel valves leak Stack shows black smoke or haze when boiler is operating Rust in water gauge Safety valves not checked or tagged Leaks Leaks

Lines uninsulated Water hammer noted Uninsulated

Steam plumes at tank vents No insulation Excessive noise Leaks

Overhaul boiler controls as soon as possible Have boiler adjusted for most efficient firing

Remove scale; check water-softening system

Clean tubes and adjust fuel burner (Ref. 1)

Repair

Check combustion controls

Check return line for evidence of corrosion (Ref. 2) Have inspection performed immediately

Have inspection performed; repair or replace Repair

Have insulation installed

Fix steam trap

Insulate if hot to touch

Check and repair leaking steam traps

Install insulation

Check and repair

Replace packing: overhaul or replace pump if necessary ers, fans, and ducts, a complete diagram of the control system showing the location of all gauges, thermostats, valves, and other components, and a list of the correct operating ranges for each dial and gauge. The descriptive material should also include any vendor-supplied manuals and the engineering diagrams and reports prepared when each system was installed or modified. Since many systems have been modified since their installation, it is also desirable to have someone prepare a diagram of your system as it is now.

Determining the present condition of the system includes preparing a diagram of the existing system based on an actual survey of the system; placing labels on each valve, gauge, and piece of equipment; and examining each system component to see if it is working. Table 14.3 gives a list of some of the more expensive troubles that may be encountered.

Significant amounts of money may be saved by proper maintenance of this system. These savings come from three sources: reducing the energy used by the system and its associated cost, decreasing the amount of unanticipated repair that is necessary in the absence of good maintenance, and reducing downtime caused when the system does not work and conditions become either uncomfortable or unsafe. Since energy maintenance on this system usually includes maintaining the temperature established by company policy, and since company policies have increasingly favored a high temperature threshold for cooling and a low threshold for heating, energy maintenance is directly responsible for realizing the considerable savings made possible by these policies. It is not uncommon for a good maintenance policy to cause a decrease of 50% in the energy consumption of a building. In addition to the energy cost savings, a good energy maintenance program can spot deterioration of equipment and can enable repair to be scheduled at a time that will not cause extensive disruption of work. Finally, there have been cases when a buildup of poisonous gas was caused when exhaust fans ceased to function. Such problems can often be avoided with a good maintenance program aimed at the ventilation system.

The controls for a heating, ventilating, and air-conditioning system can range from a simple thermostat

0 0

Post a comment