Pressure Cap And Coolant Recovery Tank; Pressure Cap Construction; Pressure Cap Pressure Control; Pressure Cap Inspection - Yanmar 3JH4E Service Manual

9.5 Pressure cap and coolant
recovery tank

9.5.1 Pressure cap construction

The pressure cap mounted on the fresh water filler
neck incorporates a pressure control valve. The
cap is mounted on the filler neck cam by placing it
on the rocking tab and rotating. The top seal of the
cap seals the top of the filler neck, and the
pressure valve seals the lock seat.

9.5.2 Pressure cap pressure control

The pressure valve and vacuum seal both seal the
valve seat when the pressure in the fresh water
system is within the specified value of 0.9 kg/cm
This seals the fresh water system.
When the pressure within the fresh water system
exceeds the specified value, the pressure valve
opens, and steam is discharged through the
overflow pipe. When the fresh water is cooled and
the pressure within the fresh water system drops
below the normal value, atmospheric pressure
opens the vacuum valve, and air is drawn in
through the overflow pipe.
The coolant recovery tank (which sill be described
later), keeps the water level from dropping due to
discharge of steam when the pressure valve
opens.
Action of pressure control valve
Open at 82-109 kPa
Pressure valve
(0.84-1.11 kgf/cm
Open at 8 kPa
Vacuum valve
(0.08 kgf/cm

9.5.3 Pressure cap inspection

Refer to 2.2.6(4).
2
.
2
, 0.82-1.09 bar)
2
, 0.08 bar) or below
273
Pressure cap
Pressure valve
spring
Fresh water cooler Copper tube
9. Coolant system
Filler neck
Overflow pipe
001585-00E