8 Jan., 1907.] Farm Engines and their Cure. 3 



cases the le'ver is made much longer than is necessary for the blowing off 

 pressure with the weight provided. Additional pressure is often put on 

 boilers through the engine-driver shifting the weight further out on the 

 lever; to prevent this, the lever should only be of such a length that when 

 the weight is at the end, it gives only the pressure allowed on the boiler. 

 The practice of hanging additional weights on the lever, as is often done, 

 should under no circumstances be allowed, and a good plan is to have a 

 notice fixed in the engine-room, stating the working pressure allowed on 

 each boiler, which should not be exceeded. The necessity for a locked 

 safety-valve is now universallv recognised, and those most approved are 

 constructed so as to admit of the valve being moved every day to prevent 

 it from sticking, but no additional pressure can be placed on the valve. 



Pressure Gauge. — A reliable pressure gauge, fixed with a syphon, 

 should be placed on everv boiler, but the practice of working them for years 

 without being tested, renders a gauge of but little value. I frequently find 

 where two boilers are connected with steam, that the two pressure gauges 

 show a difference of from 10 to 15 lbs., and I am unable to determine 

 which gauge registers correctly, or whether both are wrong. No one knows, 

 in fact. The practice of shifting the weight on the safety-valve lever so as 

 to make it correspond with a pressure gauge, which may be faulty, might 

 put an unnecessary pressure on a boiler which it might be unable to stand. 

 No pressure gauge should be allowed to be in use for a longer period than 

 twelve months without being tested. At the Ballarat School of Mines 

 there is a quicksilver testing machine. The charge for testing and for 

 giving a list of the variations of the gauge from the correct pressure at 

 different pressures, is only 2s. 6d. per gauge. By having a spare one at 

 hand a gauge could be tested at any time, if there were a doubt as to its 

 correctness. 



Check or Retention Valve. — Every boiler should have a check or 

 retention valve, and if it be fixed on the top of the shell, it should have a 

 diD-pipe leading down into the water. This pipe should be of such a 

 length that it will deliver the water about one inch below the lowest water 

 level, and a T coupling should be fixed on the end of the pipe. Short 

 pipes should be screwed into each end of the coupling to deliver the water 

 horizontally and distribute it equally. In case an accident happened to the 

 check valve, and the pipe were fixed in the manner I have mentioned, the 

 Avater could not be blown through the dip-pipe below the top of the tube. 

 This might, however, occur if the pipe were carried down near the bottom 

 of the boiler. The best place in which to fix the check valve is on the front 

 of the boiler, about an inch below the lowest water level. 



Steam Stop Valve. — A separate steam stop valve should be fixed on 

 each boiler, and when the steam is being turned on to the engine, it should 

 be done slowly. Boilers should not be connected when steam is up until 

 the pressure in each boiler is equal. The water in a boiler should be kept 

 as nearly as possible at one height, and only as much feed should be 

 pumped in as wdll supply the water used in generating steam, and will 

 allow the boiler to be "blown down " once in each shift. The plan of 

 working the water down low and then turning all the feed into a boiler, 

 should never be adopted, as it prevents regularity of steaming, and causes 

 an unnecessary expenditure of fuel. If more than one boiler is used they 

 should never both be fired at one time. One boiler should always have a 

 good bright fire in it when the other is ready for firing up. By adopting 

 this plan vou will be able to keep the steam nearly to the one pressnrp. 



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