Figure 9-34.Bucket-type steam trap.
Steam traps are installed in steam lines to drain
condensate from the lines without allowing the
escape of steam. There are many different designs
of steam traps; some are suitable for high-pressure
use and others for low-pressure use.
TYPES OF STEAM TRAPS
Some types of steam traps that are used in the
Navy are the mechanical steam traps, bimetallic
steam traps, and orifice-type steam traps.
Mechanical Steam Traps
Mechanical steam traps in common use
include bucket-type traps and ball-float traps.
The operation of the bucket-type steam trap,
shown in figure 9-34, is controlled by the
condensate level in the trap body. The bucket
valve is connected to the bucket in such a way
that the valve closes as the bucket rises. As
condensate continues to flow into the trap body,
the valve remains closed until the bucket is full.
When the bucket is full, it sinks and thus opens
the valve. The valve remains open until enough
condensate has blown out to allow the bucket to
float, thus closing the valve.
Figure 9-35.Ball-float steam trap.
Figure 9-35 shows a ball-float steam trap. This
trap works much in the same way as the bucket
trap. Condensate and steam enter the body of the
trap, and the condensate collects at the bottom.
As the condensate level rises, the ball float rises
until it is raised enough to open the outlet valve
of the trap. When the outlet valve opens, the
condensate flows out of the trap into the drain
system, and the float level drops, shutting off the
valve until the condensate level rises again.
Bimetallic Steam Traps
Bimetallic steam traps of the type shown in
figure 9-36 are used in many ships to drain
Figure 9-36.Bimetallic steam trap.