Drafting Hydrants

[Alwaysinheat 26]

What is everyone's thought:

When installing a drafting hydrant that is to be located below a water source and feed by gravity, what kind of hydrant is to be used and why? I have several thoughts and scenarios just want to determine the best for an ordinance that is being drafted for my municipality.

[dfdallen 13]

The only one we have in our town is made of 6" heavy duty plastic pipe. I don't know the reasoning of why it's like that I'm used to the rest of the town having hydrants.

[JetPhoto 626]

Hydrants are great but they do fail and it's nice to have a back up availible

[foreman1923 22]

We actually just installed one in our district and used a regular hydrant not the 6 inch pipe, works great haven't had a problem since we installed it and its been used on multiple fires. If you're ever in Mahopac falls its about 500 feet from the corner of bullethole and hill street

[Bnechis 3,961]

What is everyone's thought:

When installing a drafting hydrant that is to be located below a water source and feed by gravity, what kind of hydrant is to be used and why? I have several thoughts and scenarios just want to determine the best for an ordinance that is being drafted for my municipality.

If its below you need to use a standard hydrant because 1) the pressure may damage regular PVC dry hydrants, 2) more important you need the valve to allow you to hook it up, otherwise when you take the cap off its flowing.

[Bnechis 3,961]

The only one we have in our town is made of 6" heavy duty plastic pipe. I don't know the reasoning of why it's like that I'm used to the rest of the town having hydrants.

Because they are about $5,000 cheaper

[Alwaysinheat 26]

I have thought about using a drafting hydrant with a PIV, post indicator valve. This way you can see when the water is off or on. The only down fall to that is then the hydrant needs to be pumped out. Using a standard pressurized hydrant seems to be the way to go, but still researching my options

[firechief 2]

You have no option other than to use a standard pressurized hydrant because you need the valve so you can hook up and you will have freezing problems in winter months without the hydrant draining. We have one identical setup in my town and it works fine. The only problem we've seen is that it needs regular flushing.

[BFD389RET 112]

NFPA might have a thing to suggest about using nonapproved devices....

1) the "opening strainer" a) can't restrict water flow and needs to be kept clear of long term veggie growth..

2) head pressure (not having a clue where this is to be located) may be a significant concern when closing non approved valves (such as PVC BALL VALVES) limiting ability to close the valve fully, and also draining/freeze prevention issues

typically PVC style "Dry Hydrants" are used for drafting so these issues are lessened, The idea of Placing a Ball valve in line, to close the gravity flow is possible of course, as would be setting up some Manner of "BLEEDER" Valve placed Close enough to help reduce Back pressure on the pump* as well as draining the Barrel and LIne so that it doesnt freeze.... keeping in mind that the general piping should be below the frost like... typically PVC valves ( 1/4 turn Ball valves) can be blocked with Ice as can a "gate" style valve....

* a few years ago I had My career company out we were having a Pump Operator/engineer's test coming up so we were out drills doing some spotting and hooking up and flowing some water etc, the Boss was aware that we were involved possibly delayed.. with 3 trainees and mysel, the guy who was actually drivning hooked up front suction began the senerio ended up with a portable "stinger" and 2 1/2 and 1 3/4 ''s set up flowing when a 1st due box came in, Knowing that 2nd & 3rd due had been moved up making us 3rd, it gave me the ability to actually teach a very important lesson.... One of the fellas shut the plug down, but the valve didnt close fully because of water pressure.....I let everyone jerk around a minute and only when they all freaked out, I cracked a side cap on the plug and 2 1/2 discharge cap on the pump the valve on the plug closed and we were able to respond.... MY point is while the PIV might seem good It doesnt Have a drain, If the source creates a fair HEAD pressure and you get "STUCK" then what are you going to do? that being said Using some small "BLEEDER: pressure relief valve" may need an area of significant crushed stone to keep from "undermining" the area IF the valve breaks or freezes open or partly open....you might end up with a nice big HOLE.....

ultimately? standard is easier

[Alwaysinheat 26]

Thanks all