valves and the boilers. If repairs are needed, see that
they are made promptly. In making a quarterly check
on the blowoff valves, do not overlook the insulation,
bearing in mind that it should be kept dry. Another item
is the discharge piping leaking from the valves. Make
sure the discharge piping is not mounted so rigidly that
proper expansion and contraction are affected.
Keep SAFETY VALVES (fig. 2-4) in top working
order. At regular intervals, depending upon operating
conditions, the safety valves must be lifted manually.
At least once each year the valves should be tested by
raising steam pressure to popping pressure of the
respective valve. If safety valves function improperly,
promptly report the matter to your immediate
supervisor. For detailed information on the
maintenance of safety valves, refer to manufacturers
STEAM INJECTOR MAINTENANCE
With injectors, little maintenance is required. At
times you will have to reseat the overflow and ring
valve. Lime deposits also can reduce the operation by
closing down the size of the combining and delivery
tubes. A good way to remove lime deposits is to place
the injector in a tube of muriatic acid for several hours.
To clean the injector, remove the bottom plug (fig.
2-5). The delivery tube and ring valve drop out.
Examine and clean all passages and holes. After
cleaning, replace them in the plug (which acts as a
guide) and screw tightly in place.
STEAM TRAP MAINTENANCE
Once each month, see that steam traps are tested
for correct operation. Methods used in testing steam
traps (such as the test valve method, the glove test
method, etc.) are discussed in another section of this
Once a year, or more often if required, dismantle
and clean all traps. Inspect for the following:
1. The accumulation of foreign matter
2. Plugging of orifices, valves, and vents
3. Cracked, corroded, broken, loose, worn, or
4. The excessive wear, grooving, and wire
drawing of valves and seats
5. Defective bellows, buckets, or floats
6. Leaky vessels and pipes
7. Defective bypass valves
Repair or replace defective parts as required
following yearly inspection. Replace or repair all
Figure 2-4.A typical spring-loaded safety valve.
Figure 2-5.A cross-sectional view of an injector.