Well the 10th November 2017 marks a major milestone – the boiler passed its initial inspection and steam test, and is now certified for use. (big smiles all round).
Sadly, everything was too frenetic to take pictures during the steam test – but here it is just before we pressed go!
John, our inspector from SBAS Ltd (the SBA’s Boiler Inspecting Company) had been booked to arrive at 3:00pm – at 9:00am I set about final sealing of the try-cocks on the sight gauge – at 1:30pm I nearly called to cancel the appointment as no amount of fiddling and fitting would make them seal, with a constant drip from each of them at anything above 50psi 😦 Continue reading
Boiler Gauge Glass
Finished Gauge Glass
We decided to make the sight glass for the boiler following John King’s design, with slight modifications. Ian Cross of the SBA was very helpful and modified some existing patterns he had for “normal” reflex gauge glasses to suite rear-entry installations, and had 3 sets of these cast for our “boiler making syndicate”.
As it happened he made the castings with larger/longer mounting “lugs” so I decided to try to make the gauge with the cocks integrated into the body (as opposed to separate valves as drawn by John). This was a quite stressful decision as the cocks are not easy to make, and any errors result in a scrapped casting, but none-the-less I am quite pleased with the result. Continue reading
Well a definite milestone was reached today; the boiler passed its official initial hydraulic test at 500psi conducted by our Boiler Inspector.
It will never need to be pressed that hard again, next we have a 375psi test with all the ancillaries fitted (gauges, valves, plumbing etc.) then we put some fire in its belly and prove that the safety valves will stop the pressure going more than 10% higher than its 250psi operating pressure – then we will be allowed to insure it and use it in anger!!!
This might seem like a bit of a palaver, but a boiler failure will typically kill everyone within many feet – so it pays to take care. Continue reading
Work on the Boiler continues with the finishing and installing of the Economiser (pre-heats the incoming water to the boiler using waste heat from just before the flue) and the Superheater (adds energy to the steam on the way to the engine, again using waste heat from the flue gasses.
Milling and Drilling the Econo/Superheater Headers
As noted in the last post, I decided to mill the recesses in the two halves of the headers, as there is a lot of metal to shift, and with the “ripping” milling cutters this was by far quicker. (some pics)….
O-ring milling set up
Some finished headers
Just an update on progress with the boiler and other (interrupting) activities.
Nigel was good enough to make the trip north and assist with the tubing of the first boiler.
This was actually a simple, if repetitive, job.
Tubed: The view from the fire!
Fitting the tubes
The tubes are ready to fit…!
After what must have been an epic session, Nigel and his assistants in the southern group of the “Boiler Collective” have now cut, deburred and bent the 600+ tubes for the three boilers we are building.
The pictures below show the extent of this activity, and the bending jigs they made…. (thank you men)!
We first made a trial set by measurement from and comparison to the drawings (yes, yes, I know “never scale from drawings“), we then test fitted these and they were good. So then the team cut the rest using an angle grinder in an adjustable jig. Then cleaned up the ends with a bench-mounted wire wheel, and finally bent them to the appropriate angles using the bender we “pre-calibrated” in the trial run.
First cut some cunifer to length
Tube ready to be bent
First bend in at correct angle.
Enough tubes for the 3 boilers
More Progress on the Boilers – and a “Contraption”
We now have all the components to commence the “real construction” of the boilers.
Boilerplate and Steel
As you will recall from earlier posts we have drilled the holes in the steam and mud drums, and ordered the plasma cut 3mm plates for the housings from Ashby Welding in Church Crookham, and (after a lot of searching) ordered the 20mm Boiler Plate for the drum ends – which was eventually sourced from Brown MacFarlane in Stoke on Trent with the very capable assistance of their Account Manager Alan Taylor. So the Landy made another round trip to Hampshire with a good load of steel in the back! Continue reading