| Gallery, Projects and General > Project Logs |
| Tina :- Engine and Boiler Build |
| << < (11/22) > >> |
| klank:
Hi Strw Yup - made from a kit of castings eventually furnished by a certain vendor (located up your way) after all kinds of trials and tribulation. I just put the photos up to show a fish belly type of con. rod. If you like draw - filing, its a good exercise - the trouble was getting two of them to look identical! For Tina, one is no real problem. Peter |
| Rob.Wilson:
Hi Peter Crank disc and other parts turned out spot on :clap: :clap: :clap: :clap: ,,,,,,,,, :thumbup: Rob |
| loco:
Now for the next exiting episode!!! STAYS These are only needed on FLAT sections of a boiler to prevent the sides bowing out under pressure. Consider a loco boiler. It basically comprises a cylinder fixed to a square or rectangular box. The cylinder is self supporting whilst the box is not. At the front end of the boiler is a flat plate ( smokebox tube plate ) . This is stayed to the throatplate in the firebox by means of the tubes and is usually stayed to the backplate or backhead by means of longitudinal stays, 1 often being hollow and used for the blower. Remaining stays will be solid. They should be threaded, blind nutted and silversoldered. However, opinion varies as to the real use of these longitudinal stays for after silver soldering such stays are observed to have sagged so much in the middle that their efficiency is doubtful. The top or crown of the firebox is usually stayed to support itself the shape being round or rod stay, or of the girder type, these being usually riveted and silver soldered. The firebox stays are the most important. There size and spacing should be chosen with care. They are there to support the unsupported sides which are not self supporting - got it??? The boiler designer will have done the calculations for the spacing. This boiler is basically a self supporting structure. It needs no side stays and the tubes serve the purpose of longitudinal stays. Fancy an experiment?? Find a square plastic bottle and a round one. Holding carefully half way up, blow into it and feel the sides expanding - or not. Notice how the manufacturer has added corrugations to make it more rigid. Think about the pressure inside - does it go fizz when opened? Next time boiler regs and testing. Pete |
| loco:
Now for the next exiting episode!!! This applies to the UK and those of you across the pond will have your own regs. ALL new boilers need to be proved or tested. Would you buy a gun that had not had the barrel proof fired at twice the normal velocity? The initial hydraulic test is at 2X working pressure and such a test is valid for 4 years before the steam test. This allows s-l-o-w builders to complete. The holes are all plugged and NO boiler fitting should be on the boiler. Having passed, all the fittings are installed, piped up etc ready for a steam test at normal working pressure during which time the safety valve should be set and the pressure gauge red lined. A pass means the boiler is valid for 1 year. Subsequent hydraulic test shall be at 1.5 times working pressure annually followed by a steam test. This applies to all boilers over a capacity of 3bar/litres. The GLR boiler running at 80 psi just exceeds that level and requires CE marking if made commercially but is down rated to 40psi so it does not. If you are making it the 80psi is fine. The kit of bits says 80 psi whilst a completed ready to run boiler is rated at 40 psi. However every boiler I make is tested to 160psi hydraulically. In a former life I was a teacher of engineering, metalwork and woodwork. About 20 plus years ago a lad built one of these boilers. After much soldering and resoldering and resoldering the boiler was finished and held 160psi.After he left and did not want the boiler my technician decided a destructive test should be carried out. He made suitable plugs, secured with Boss white ( no PTFE in those days ), and after fixing it to a bench outside on the field and with the plugs facing the opposite way all was ready. Being the man he was, readings were taken to see how much the barrel would bulge as the pressure increased. At 50 psi intervals we stopped and made measurements. The gauge only went up to 250 psi so we stopped. The increase was only a few thou. No bangs, creaks or groans. DO NOT DO THIS TO YOURS. We cut the boiler in half to examine the inside and the tubes were perfect. Pete |
| loco:
help I can build boilers but how do I put a photograph here??? Pete |
| Navigation |
| Message Index |
| Next page |
| Previous page |