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Post by wannabebuilderuk on Sept 23, 2020 3:17:39 GMT -5
I was thinking 3mm "flanges" since tank is only 2.5mm but I guess I'd want closer to 5mm or just a decent amount of bolts on the flange?
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Post by racket on Sept 23, 2020 4:06:20 GMT -5
With 3 mm flanges you'd need a bolt every half inch , even at 5 mm it'll be every inch , we are dealing with a pressure vessel
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Post by wannabebuilderuk on Sept 23, 2020 4:36:27 GMT -5
So at 235mm dia between centres on the 260mm 5mm flange that's a circumference of 738.27mm so that's 29 bolts at 25.45mm between bolts.
On one hand that'll be a nice aviation look to it but fuck drilling and marking that lol.
What thickness do you suggest then, 8mm with 15 bolts spaced 49.2mm apart?
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Post by wannabebuilderuk on Sept 23, 2020 12:42:15 GMT -5
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Post by racket on Sept 23, 2020 16:29:26 GMT -5
Hi Ben
LOL...If it looks right , it is right ...................but there are set guidelines, do a Google.
Cheers
John
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Post by slittlewing on Sept 23, 2020 16:55:41 GMT -5
If your vessel has flat ends I suggest 5mm top cap and 10mm turbo flange, I went thinner and paid the price in problems! As for drilling all the holes.. I was too lazy so suggest laser cutting - guaranteed perfect fit...  Nice pressure relief valve although I don’t think you will need it with PWM control 🙂 edit: regarding gaskets, I tried using “high temp gasket paper” for top cap, survived short running but fell apart when I removed top cap thereafter. recommend copper gasket instead:  Cheers Scott |
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Post by wannabebuilderuk on Sept 23, 2020 17:08:31 GMT -5
I must be searching the wrong terms as I can't find anything related to what I'm looking for lol. Thinking about it 5mm minimum is more appropriate so I'll go for 6-8mm depending on cost.
Question for all, dome end vs open end lip mounted F/T, what is better or are they both good in their own ways since the dome end style allows for better flow at the top and keeps the lid cooler but is harder to make and increases the length slightly. The open ended lid mounted style allows for a simpler design that's slightly shorter however there's no barrier between the lid and the flame.
Any other main differences between the two?
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Post by wannabebuilderuk on Sept 23, 2020 17:12:09 GMT -5
Hi Scott,
I'd probably tack weld them together and drill the holes at the same time, currently deciding on if I want the flat end or to use the existing end of the tank and use a domed F/T
Also I may not need it but doesn't hurt to have it in as a safety incase something goes wrong (blocked nozzle/ fuel line etc) and the pressure builds above the 600psi full throttle that I'll be running (hopefully)
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Post by slittlewing on Sept 23, 2020 17:19:49 GMT -5
As your tank (combustor outer) already has a domed end, you may aswell use it to your advantage as you don’t need to fabricate that part. The flame tube itself can have a flat top inside that if you like, as there will be no pressure differential across it. There’s a few ways of doing it depending where you want your bolted or v-band connection flange (top cap, mid way or at turbo end) - there’s every type on this forum! Obviously your fuel injector needs to poke through to the FT though, and you need to account for expansion (either with a slip joint or a boss with your fuel injector that will poke through to the FT)
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Post by wannabebuilderuk on Sept 23, 2020 18:04:12 GMT -5
I never really thought about a flat top F/T, wonder how massive of a difference it would give vs a dome style - easier to drill holes in that's for sure!
I was thinking of cutting the tank where the upper weld is and putting the flanges there, and maybe a flange on the bottom but would be cheaper just to weld the plate on instead and unbolt the elbow and C/C from the turbine flange as one.
As for securing the F/T the top of the tank has a m22*1.5 thread and I still have both brass plugs however they'd probably get close to their melting temp being 1" away from a 1.5mm stainless steel wall containing 1000+°c flame lol.
I was thinking of a bar that screwed into the m22 from the inside, 1" between the C/C end and the F/T end, the F/T end secured between two nuts. The end of the bar inside the F/T will be threaded 9/16-24 unef for the nozzle and drilled all the way through with the end outside threaded 1/4bsp.
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Post by racket on Sept 23, 2020 19:13:05 GMT -5
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Post by wannabebuilderuk on Sept 23, 2020 19:38:59 GMT -5
Like being a kid in the candy shop, too many choices 😂 Found a massive error on this listing for m22 stainless steel threaded bar www.ebay.co.uk/itm/133489813850. Select m22 500mm and it's only £3 lmao should be around £35. I like the compression olive setup on the first link John, just would be interesting to find the right setup for the existing m22 hole. For the base end cap I'll go 6mm permanently welded to the c/c and since it'll have the t6 flange rectangle cutout and corresponding rectangular profile elbow (unless 3.5-4" pipe is better )welded to the cap which will stiffen it up anyway. For the f/t access I'll put a 5mm flange on either half where the weld seam is, approximately 1/4 away from the top of the c/c. Will do a simple drawing tomorrow for those like me who are visual learners as I tend to picture things perfectly in my head but suck at verbally communicating them lol Time to sleep as almost 2am and if I keep reading all this build threads I'll not get up for work! |
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Post by wannabebuilderuk on Sept 24, 2020 3:32:40 GMT -5
 Green is pipe, red is the proposed flange. Thinking of m10 bolts so have drawn in the right sized washer (25mm wide) for a visual reference. Total of 15 bolts. Plate will be 7 or 8mm. Just under 2" between centres would allow a minimum amount of flex I'd say so personally I'm happy (plus nice aerospace look  ). Can use a coper gasket if needed but overall what do you guys think |
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Post by racket on Sept 24, 2020 3:39:42 GMT -5
yep, 8mm flanges
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Post by wannabebuilderuk on Sept 24, 2020 4:41:04 GMT -5
Can't find a 3.5" large radius mild steel pipe so I'll see if I can get something from the pipeshop at work or would a rectangular profile elbow be fine? i.e what I modeled previously  Only thing I can see being an issue is that since its not a sore thumb design the rectangular profile will be 90° instead of having rounded edges so would the rounded edges on the turbine flange be an issue? |
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). Can use a coper gasket if needed but overall what do you guys think