If your system is gridded it might be pretty hard to pick through the worksheet to find out what’s going wrong. To troubleshoot, I’d recommend breaking the grid if there is one so that you have a much simpler branch system to work through. You might need to flow less heads temporarily so that your flow rates/velocities don’t get so high that the calculation gets wonky. See if you can start to find any portions of the two calcs that DO match as a starting point and then work towards were they diverge.
Your flows will start to vary when discrepancies in your calculated friction loss create higher required pressures at branching connections causing over-discharge down the secondary lines. This additional flow will exacerbate the variation in required pressure which will then compound to cause more over-discharge and more friction-loss as you make your way back to the riser. Sometimes those very small differences of a psi or two between the initial heads/branches can add up to major losses downstream as your flow rates over-burden your selected pipe sizes. Also quick things that are easy to check. * Double check your pipe diameters and C-factors * Equivalent lengths in autosprink! If you are using specific manufacturer parts, autosprink generally has them pre-loaded with their specific friction-loss characteristics that a different from the NFPA-13 standard ones. If you have fittings applied, then remove them temporarily or switch them to generic to see if that makes things match. Just think of this as a great opportunity to sharpen your manual calculation skillset 😊 Hope this helps! Eric Rieve Rieve Fire Protection From: August Hoffman <[email protected]> Sent: Wednesday, June 7, 2023 5:41 PM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]> Subject: [Sprinklerforum] Re: AutoSprink Vs HydraCalc Thank you, it must be user error and I did something wrong with my inputs into HydraCalc. My AutoSprink drawing is clean with all proper fittings for sure, the safety makes more sense on that calc. Ive used AutoSprink for 4+ years now but only just started HydraCAD and HydraCalc a few months ago. Now to figure out what I did… AUGUST HOFFMAN DESIGNER NICET WBS 153613 From: Anthony Johnson <[email protected]<mailto:[email protected]>> Sent: Wednesday, June 7, 2023 2:17 PM To: Discussion list on issues relating to automatic fire sprinklers <[email protected]<mailto:[email protected]>> Subject: [Sprinklerforum] Re: AutoSprink Vs HydraCalc I use hydra-calc everyday but have compared it's calculations to other programs with very little differences. With the disparity you're experiencing I would be looking at pre-set hazen-williams coefficients being identical, the NFPA fitting multipliers, checking pipe tables for identical pipe ID, backflow friction loss curves etc.. In Hydra-calc make sure auto adjust fitting lengths is checked. [https://s-install.avcdn.net/ipm/preview/icons/icon-envelope-tick-green-avg-v1.png]<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free.www.avg.com<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> On Wed, Jun 7, 2023 at 1:29 PM Brett Peters <[email protected]<mailto:[email protected]>> wrote: Never used HydraCalc but I’ve redrawn systems done from SprinkCad and the Calc’s were pretty much identical when I was done. Double check that you didn’t end up with double pipe or Mech tees or something like that On Wed, Jun 7, 2023 at 2:16 PM August Hoffman <[email protected]<mailto:[email protected]>> wrote: I was wondering if anyone has compared the calculations between HydraCalc and AutoSprink calculations. Ive been messing around with the 2 lately and I am not getting the same safety margins. .5 or even 1 psi difference wouldn’t surprise me but I am getting 13-20psi discrepancies. I have triple and quadruple checked the calcs and while all the elevations, pipe lengths, pipe types, fittings ext. are the same I am getting different flows and friction losses at different locations along the calc. I manually input all the HydraCalc info per my plans using the same nodes as AutoSprink to better follow the calc. One issue may be the order I input into HydraCalc but that ultimately should not matter, the path of the water is still correct and the same for both calcs: Example: For AutoSprink the calc is separated by each individual path – for an ESFR calc it follows one line back to the source, then the other 2 lines. Mean while I have my HydraCalc sectioned off by *Remote line 1-3, *Float Main, *West side of feed main, *East side of feed main, *Riser, *Underground. So the calcs side by side do not mirror each other but the water flow path is still the same. Most friction losses match with a margin of .02, but the flows very and a few stretches of pipe have .5-1 more psi pressure loss on AutoSprink. Both programs are the latest versions. Im just wondering if one is more accurate, or if anyone else has compared the two with the same calc. Im not ruling out user error, I am sure that is the case but I have not been able to find the issue. Thank you, AUGUST HOFFMAN DESIGNER NICET WBS 153613 _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]> -- Thank You Brett Peters PFPS Ltd (780) 777 0568 Sent From My iPhone _________________________________________________________ SprinklerForum mailing list: https://lists.firesprinkler.org/list/sprinklerforum.lists.firesprinkler.org To unsubscribe send an email to [email protected]<mailto:[email protected]>
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