Yanmar 3YM30 Service Manual page 62

3) Heat exchanger body water leakage test
a) Compressed air/water tank test
Fit rubber covers on the fresh water and
seawater inlets and outlets. Place the heat
exchanger in a water tank, feed in compressed
air from the overflow pipe and check for any
(water) leakage, (air bubbles).
Test pressure
b) Use of the tester
Fit the fresh and seawater inlets and outlets with
rubber covers and fill the fresh water tank with
fresh water. Fit a pressure cap tester in place of
the pressure cap, operate the pump for one
minute and set the pressure at 0.15 Mpa (1.5
2
kgf/cm , 21.33 lb/in.
pressure will not rise. If there are no leaks the
pressure will not fall.
4) Pressure cap inspection
a) Remove scale and rust and check the seat and seat valve, etc. for scratches or wear. Check the
spring for corrosion or settling. Replace if necessary.
[NOTE]
Clean the pressure cap with fresh water as it will not close completely if it is dirty.
b) Fit the adopter on the tester to the pressure cap.
Pump until the pressure gauge is within the
specified pressure range 0.074-0.103 MPa
(0.75-1.05 kgf/cm
The cap is normal if the pressure holds for six
seconds. If the pressure does not rise, or drop
immediately, inspect the cap and repair or
replace as necessary.
0.20 MPa (2 kgf/cm
2
). If there are any leaks the
Do not open the pressure cap while the engine is running or right after
stopping because high temperature steam will be blown out. Remove the
cap only after the water cools down.
2
) and note the gauge reading.
Pressure gauge
Air hose
2
)
Rubber cap
Rubber cap
Pressure cap
42
2. Inspection and adjustment
Filler cap
Rubber
cap
Test tank
Heat exchanger
Pressure tester
Pressure gauge
Rubber cap
Tester