Horizontal 3” Boiler Instructions v1.2
Copyright - Chiltern Model Steam Engines
Page 9.
working pressure within the canister/tank – this is not recommended for less experienced
operators/builders.
If however, the canister/tank is allowed to get too hot, the pressure of the gas inside the
canister/tank can become dangerously high and this must never be allowed to happen. It is
important therefore that there is plenty of air space between it and any hot items such as boiler or
steam pipes. The gas canister/tank should be slightly warm to the touch, no warmer.
Please refer to manufacturer’s guidance and ensure that their maximum operating temperature is
never exceeded. Usually the temperature of the canister/tank should not be allowed to get higher
than 30 degrees Celsius.
Pressure Vessel Care and Maintenance
It is recommended that the boiler be drained after use.
Boilers do have a finite life so it is recommended that if the boiler is used regularly or operated in
public it should undergo the following checks, carried out by a “competent person”, club, society, or
pressure vessel manufacturer, every one to two years:-
1.
Thorough visual inspection.
2.
Hydrostatic pressure test to not less than 1.5 and not more than 2 times the maximum
working pressure.
3.
Steam pressure test to check the correct functioning of the safety valve.
Troubleshooting
The tiny gas jet hole can become blocked by small particles of dirt or if left unused, making the
burner difficult to light, burn weakly on cold days or fail completely. If any of these should happen,
clean out the jet as follows:
1.
Disconnect the gas supply pipe from the jet carrier. Note when connecting or disconnecting
the gas pipe, do not use excessive force as it is possible to cause damage by bending the
pipe.
2.
Slacken the screw retaining the jet carrier in the burner mixer tube and slide it out.
3.
Remove the jet from the jet carrier using a 4BA spanner. Wash out the jet in fast evaporating
thinners (Cellulose or similar). Blow through the jet from the front, which should clear most
blockages. Although the hole through the jet is tiny, if you hold it up to the light you should
be able to see quite clearly if it is blocked or not. If in doubt, fit a new jet - they can be
purchased from model engineering suppliers – the boiler is fitted with a No. 8 Gas Jet. Do
not use wire to clean the jet as this can damage the precision hole and may upset the
delicate balance of the gas system.
4.
Reassemble in the reverse order, wrap a little plumbers PTFE tape around the jet’s and other
connection threads and ensure all gas connections are tight. Re-position the gas jet carrier in
the burner mixer tube, as described above.
