Dry Hydrant location

[Meadowbend99]

I'm working on a project where a building's sprinkler system is supplied by a water tank and our secondary water supply is a dry hydrant supplied by a pond on site. There are several buildings on this site and we located the dry hydrant to be centrally located between all of them just off the fire lane.

The Fire Marshal is requesting the dry hydrant to be a min. of 100' from the buildings and within 10' of a fire lane. Unfortunately, to do that the dry hydrant will now be quite a distance from the buildings. I don't see any language regarding how close it needs to be, we were trying to get it within 400' of all buildings but that is for wet hydrants. With the relocation it is now 500' to the furthest building.

What is the reason for the dry hydrant needing to be 100' from any buildings?

 

[cda]

Fire department connection

With in 100 feet

That is normal

 

[cda]

“””Unfortunately, to do that the dry hydrant will now be quite a distance from the buildings. ””

If it is required with in 100 feet ???

Can you define your “”dry hydrant””

 

[Msradell]

“””Unfortunately, to do that the dry hydrant will now be quite a distance from the buildings. ””

If it is required with in 100 feet ???

Can you define your “”dry hydrant””

A "dry hydrant" is one it's not connected to a pressurized water supply. It's basically just a pipe that extends out into a pond or lake that a fire department can use the draft water from the body of water. Many rural areas have them set up on farm ponds etc. The advantage to them is that the fire department can start pulling water much faster than if they have to lower their own hoses into the body of water.

 

[IJHumberson]

I can see why they would want the dry hydrant to be within 10 feet of the emergency vehicle access lane, but I've never heard of requiring the hydrant to be at least 100 feet from the building - usually one would want it closer to the building so that the same engine pumping from the dry hydrant could supply attack lines. That's a new one on me.

 

[Msradell]

Any dry hydrant I've ever seen it's relatively close to the water source. It's harder to draw draft thru them if they are large distance away from the water source.

 

[Builder Bob]

Fire Department Connection - you may have to extend the FDC's fire lines to the location desired for the dry hydrant......

507.5.1.1 for standpipe systems and ultimately you have to meet the approval of the AHJ - See IFC 507.1

 

[cda]

waiting for OP

To define what they deem a dry hyrdrant

 

[Msradell]

waiting for OP

To define what they deem a dry hyrdrant

I gave you the definition of a dry hydrant in post #4

 

[Insurance Engineer]

If this is “drafting hydrant” is not connected to a pressurized water supply this presents a potential problem for the FD. The hydrant would need to be located within a few feet of the road so the FD can use “hard suction” hose to draw water from the hydrant. The fire engine will draft the water from the hydrant by lowering the pressure in the hard suction and pipe to draw the water into the engine. Depending on how far the hydrant is from the pond and difference in elevation between the two this may take time to get going and have limits on how many gpm the FD will have available. See NFPA 1142 Standard on Water Supplies for Suburban and Suburban and Rural Fire Fighting for detail on the details on dry hydrant.

 

[Builder Bob]

Bingo IE. The dry hydrant needs to have the shortest run of pipe (horizontally as well as vertically) as friction loss in drafting is still our enemy when it comes to discharging or siphoning (drafting) water.

Also as a note to the unwise about dry hydrants - water seeks its on level................running pipe up the slope for dry hydrants doesn't work.