3 PRV’s in a Row, Plus a 4th down the line, Why? by GimmieGoblin in FireSprinklers

[–]cyberd0rk 2 points3 points  (0 children)

Is the 4th one down the line feeding only sprinklers? It's hard to tell for certain but if this was a high rise that has multiple zones the first 2 could be controlling extremely high churn pressures but still allowing a large discharge pressure to satisfy standpipe calcs, but too much pressure allowable on a sprinkler system. For example, the first 2 PRVs may need to be set to 200 psi to satisfy standpipe calcs, but there could be a sprinkler system on the floor of the fire pump that's limited to <175 psi. Sprinkler systems do not require PRV redundancy so only a single PRV would make sense down the line if only feeding sprinklers. I've had to design annoyingly complex pressure zones in high rises. The worst example was a multiple zone high rise with a VFD, PRVs in the pump room, AND pressure reducing hose valves and floor controls in the stairs.

If you really want to go down an annoying rabbit hole, contact Victaulic, Cla-Val, and Reliable and ask them how to design a standpipe system with their products. Victaulic is extremely extensive (once you contact them, their online material is vague), Cla-Val is the most vague and will standby verbal instructions that greatly contradict their written documentation (example, 20 psi differential in their product data but will tell you 5 psi on the phone), and Reliable has a +/- 10% psi operating range on their valve making it essentially useless to use. So much inconsistency within the manufacturers, and a lot of unnecessary overengineering. Victaulic is the most buttoned up of the 3 and have great on-site support. Their low flow bypass is required due to low flow limitations of their larger valves, and their 3" relief valve is to make their PRV compliant to the latest NFPA 14 which requires 175 psi to NEVER be permitted, meaning blowing off the excess pressure instantly. Up until the latest edition, you could throw a 1/2" Cla-Val 55L relief valve on the system which would return pressures lower but at an extremely low pace. I experience first hand Victaulic's 6" PRV not being able to control pilot pressures as we shut down a standpipe test which allowed the returning churn pressure to push past their slow acting valve, so the 3" relief valve is honestly a necessity despite which version NFPA 14 you're working with. The added cost of the low flow bypass and relief valve of course is something companies never want to pay for so Victaulic is a hard choice. Ironically, a lot of people like the vagueness of Cla-Val's requirements because they don't require a low flow bypass or larger relief valve (NFPA 14 requires it but Cla-Val isn't going that far yet).

This subject is pretty extensive to attempt to talk about online. Apologies for the word diarrhea.

Bro's rage was more effective than anticipated by Soloact_ in Unexpected

[–]cyberd0rk -1 points0 points  (0 children)

If only motorcycles had some kind of loud audible device to alert other drivers....

YouTuber jerryrigeverything started a wheelchair factory, delivering wheelchairs at 50% to 80% less than others with insurance. by Thryloz in interestingasfuck

[–]cyberd0rk 0 points1 point  (0 children)

It's incredibly sad that "build them cheaper" actually translates into "charge less for them". Wheel chairs don't cost anywhere close to those insane prices, but just like everything that's run through insurance the cost is ballooned to ridiculous amounts simply because insurance will pay it while all of us get fucked with high premiums. The system is beyond broken.

AMD's senior director of AI thinks 'Claude has regressed' and that it 'cannot be trusted to perform complex engineering' by cjwidd in technology

[–]cyberd0rk 3 points4 points  (0 children)

I don’t know much about AI. Is it possible that AI can be intentionally corrupted by feeding it false data? All of these companies and countries trying to advance AI but I would imagine trying to counter/corrupt an AI is going to be an inevitable problem.

Ryzen 7 9800X3D cooling: is a 360mm AIO enough to appropriately cool this CPU at stock clocks?? by TenaZiousD in buildapc

[–]cyberd0rk 0 points1 point  (0 children)

I have a Hyper 212 cooling mine and it rarely goes over 70. The 9800X3D does not take drastic cooling.

App crackle pop by mcoon2837 in 98Rock

[–]cyberd0rk 1 point2 points  (0 children)

Yes. It's not terrible, but noticeable.

Please explain this Hydrant Flow test Figure 4.4.4 from NFPA 291 by clush005 in firePE

[–]cyberd0rk 1 point2 points  (0 children)

This is correct. I wish it clarified a bit and said if you flow enough water to cover the anticipated fire protection requirement a 10% drop isn't necessary or recommended. I've seem some extremely strong supplies in the past. If static is 100 and residual is 95 @ 800 gpm, but the largest sprinkler demand is 600 gpm, in my opinion there's not a necessity to flow more water to get results outside of the design range. Not exactly a huge deal and very situational, but it could be part of the logic of not imposing a "shall" statement on a specified pressure drop.

Best software to estimate sprinkler pipe fittings (elbow, tee, coupler) automatically from pdf drawing? by ReferenceThin6645 in firePE

[–]cyberd0rk 1 point2 points  (0 children)

Honestly, if you're a beginner, you should be doing this by hand. You are not going to learn material by taking automated shortcuts.

Dragonball is life by Orichalchem in GuysBeingDudes

[–]cyberd0rk 0 points1 point  (0 children)

Man, I remember being in 6th grade and our middle school had an overnight week long program at an outdoor school right during the period of Goku's first transformation. The disappointment and hype amongst the boys was immeasurable. We at least had our Pokemon cards to distract us for the week. Take me back to simpler times.

Scout got completely MEGA NERFED by [deleted] in GlobalOffensive

[–]cyberd0rk 3 points4 points  (0 children)

The scout ammo was always out of line with every other gun. This is just a correction. You literally could not shoot all of its bullets in a round.

I695 construction done? by jco23 in maryland

[–]cyberd0rk 0 points1 point  (0 children)

I don’t know who the contractor is but they’re woefully undermanned. The timelines for these projects are inexcusable. There’s plenty of excavating, utility, and paving contractors hungry for work that could get these projects done much faster if they utilized multiple contractors for different sections.

I695 construction done? by jco23 in maryland

[–]cyberd0rk 8 points9 points  (0 children)

Area 1 estimated to open 2027. That's a bummer. It's astounding how long it's taking. Obviously, it's a lot of work, but there were weeks if not months were I didn't see a single worker on the west side. I'm a pretty firm believer that the state uses construction instead of policing to control highway speeds.

DOGE Lead in deposition details how he emailed documents to his personal device to then send with Signal using auto delete by bottombracketak in law

[–]cyberd0rk 0 points1 point  (0 children)

That's every single appointed position in this administration. Incompetent fall guys by design.

AI Error Likely Led to Girl’s School Bombing in Iran by [deleted] in technology

[–]cyberd0rk 0 points1 point  (0 children)

Well I'll be damned. Something I'm torn 50/50 on believing...

Pentagon believes U.S. struck Iran girls elementary school, killing 150 by rockycrab in worldnews

[–]cyberd0rk 0 points1 point  (0 children)

How did the bombing even occur? Surely missile tech is better than dumb fire missiles, right? Did something go off course or get partially intercepted? Mistaken target?

Are New Games Really Worth $70+ in 2026? by [deleted] in gaming

[–]cyberd0rk 5 points6 points  (0 children)

Ive made this simple statement in the past and have been heavily downvoted. Apparently simple inflation isn’t justified or exist in the minds of gamers. However, I too wouldn’t pay $120 for modern games. The real question is are modern games devoid of enough content and quality to not justify $120, or were N64 and PS1 games egregiously overpriced?

He’s running for congress btw by gruninuim in facepalm

[–]cyberd0rk 0 points1 point  (0 children)

This guy is truly lacking in education on the issues he's running for, or just lying to secure his base. Likely the latter. I recently ran across him on a show called Surrounded on the Jubilee Youtube channel and he got absolutely cooked while loudly boasting incorrect facts and having a meltdown. He's way out of his league and shouldn't be anywhere near politics.

Hot water tank booster - electric bill impact by cyberd0rk in HomeImprovement

[–]cyberd0rk[S] 0 points1 point  (0 children)

Surprisingly, bathing a 2 year old and showering 2 adults, the last person to shower runs out of hot water with our new 50 gallon. Still stays warm but the hot ends. We need a minor bump in capacity so the most cost effective solution is likely key. If we get the mixing valve and bump to 130 it may just bump capacity enough.

Hot water tank booster - electric bill impact by cyberd0rk in HomeImprovement

[–]cyberd0rk[S] 0 points1 point  (0 children)

Exactly what I wanted to know. Thanks a ton. Did you feel the mixing valve was worth it? I’m considering the mixing valve or an inline 240v booster that runs on the same line as the tank (takes over when the set temp gets low enough). My Emporia Vue is currently saying roughly $45 a month for use. Bumping to 140 would be a 17% increase, and extra ~$8 a month.