RURAL WATERLINE 1

[HELLA21]

thread164-244163

IT WAS REFERENCED IN THE PREVIOUS THREAD, IF U CAN'T OBTAIN FIRE FLOW, THEY INSTALLED A DRY HYDRANT WITH AN UNDERGROUND STORAGE TANK. I'M THINKING THIS WOULD BE A PRACTICAL WAY TO GO. CAN ANYONE POINT ME IN THAT DIRECTION FOR INFORMATION ON THE MINIMUM SIZE OF THIS TANK, CAD DETAILS, COST COMPARISON?

AS MENTIONED YESTERDAY I HAVE STATIC PRESSURE OF 130 RESIDUAL PRESSURE OF 88 AND A FLOW RATE OF 100 GPM. IT CURRENTLY HAS A 2" LINE BORED UNDER A HIGHWAY AND I HAVE A PROPOSED THREE INCH LINE RUNNING 800 FEET TO A DEAD END LINE WHERE I'M WANTING TO INSTALL A DRY HYDRANT. I HAVE NEVER WORKED WITH DRY HYDRANTS BEFORE THOUGH

 

[redbridge]

Are you required to provide fire flows in a rural areas? If so, what state/country are you working in? Rural water lines that I have designed had to be able to flush at 2.5 ft/s and maintain at least 20 psi throughout the system and every meter must have 30 psi.

 

[HELLA21]

RURAL, GOSHEN ARKANSAS ITS WITHIN THE CITY LIMITS AND CALLED A SUBDIVISION, SO YES IN THIS CASE THE CITY ORDINACE SAYS I NEED TO PROVIDE A FIRE FLOW, OR I MAY BE ABLE TO INSTALL A DRY HYDRANT, AND GET MY WATER TO THE PROPOSED TANK THROUGH MY PROPOSED 3" SERVICE LINE THAT WOULD FILL THE TANK AND KEEP IT FULL. JUST NEVER DONE THIS BEFORE.

 

[bimr]

Here is an example of a "dry hydrant".

http://www.dof.virginia.gov/fire/dry-hydrants.shtml

http://www.ettfire.com/underground_tanks.html

http://www.dryhydrants.com/news&info.htm

ftp://ftp-fc.sc.egov.usda.gov/NHQ/practice-standards/standards/432.pdf
"Water Requirement. The quantity to be
considered available to a dry hydrant is the
minimum available (at not over 15 feet total
static lift) during a drought. A minimum of
30,000 gallons (1.1 acre-inches) of pumpable
impoundment water or a minimum pump flow
rate of 250 gpm without interruption for 2 hours
is considered a dependable water supply."

 

[rconner]

Sounds like very small pipes, very high velocity, and also with very high pumping head loss if must fire flow 250 or more? gpm (equivalent to 360,000 or more gpd). For such very high velocity, hope pipes are pretty strong, too!