The Dry Hydrant Flush Kit allows installation of a Dry Hydrant
below ground level. This type of installation eliminates any environmental
or vandalism concerns which one may have. The flush mount kit includes
a molded polymer enclosure with a lockable lid, a quick connect
male adapter with cover cap, and a 6"x12" highly reflective
decal attached to the lid.
The flush mount system requires a flexible suction hose with female
cam lever connec-tions or a hard suction hose adapter for ease of
connection with NST couplings. This adapter may be purchased separate
if required.
The Flush Kit is used with the standard 6" Dry Hydrant by
utilizing either the straight or 45 degree intake assembly. This
arrangement assures full flow & straining capability thru both
the underwater strainer and our secondary conical strainer. The
quick connect suction hose adapter is available in a 3", 4",
5", and 6" cam lever connection.
Any pond, stream, or buried underground tank may be used as a water
source. Swimming Pools can also be plumbed into Dry Hydrants for
use. To put these sources in perspective, a one acre pond roughly
1 inch deep is equivalent to 30,000 gallons of water. This is equal
to the required 250 gal/min 2 hr. flow, established by ISO for "Water
Supply" in a Class 8 or lower rating.
In selecting your Water Source one should first be sure it is adequate
during drought conditions. These requirements may be found in the
(ISO) Insurance Services Office "Fire Suppression Rating Schedule",
or equivalent Insurance Regulations used by those states not covered
by ISO. A point 2 feet below the drought level should be adequate
for determining the horizontal lay of the pipe.
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VERTICAL LIFT:
While lifts of 22 ft. may be obtained under ideal
conditions, it is not recommended installations exceed 15 feet.
Pumps other than Class A should avoid installations which exceed
10 feet. Vertical lift may be determined by measuring the distance
from the waters surface to the inlet of the pump as noted in the
above diagram.
ACCESSIBILITY & COORDINATION:
Hydrants should be located to provide an immediate
water supply in an emergency situation. Because of this several
considerations regarding location and accessibility must be met.
- Access suitable for all weather conditions.
- Sustained maximum grade of 8 percent.
- Road width should be at least 12 feet.
- Site should have proper drainage.
- Provide proper erosion control, especially after construction.
- Locate hydrant near homes or structures if possible.
- Must be able to get permission & permits as necessary.
Permission of the land owner is needed before
a Dry Hydrant site survey can be conducted. It is best if someone
known by the land owner ask about doing a survey before tres-passing
on ones land. He should explain the benefits, and stress the
pond will not be "Sucked Dry" by the fire department.
Upon site selection written permission should be
obtained. Sites on certain waterways and governmental properties
may require special excavation and environmental permits. All
permits must be cleared prior to excavation. Cutting of trees,
landscaping and etc., should be discussed with the land owner
and put in writing.
Coordination with local fire departments and property
owners should be made clear, and also be included in the signed
agreement. This will clarify issues such as insurance, usage of
water supply, and notification to local fire departments prior
to draining of the pond.
Land owners installing Dry Hydrants should consult
local fire departments on hardware sizing, hydrant location, and
other requirements for obtaining lower insurance rates. Local
departments should have approval procedures, an inspection procedure,
and hydrant cards established for semi-annual maintenance.
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WATER SOURCE EVALUATION:
Upon selection of a location the water source must
be evaluated to assure it's ongoing availability. Several points
should be considered:
- Condition of the pond dam - Is it strong? Does it leak?
- Does the landowner have future plans for the pond?
- Distance of hydrant to pond.
- Static lift.
- Depth of water at the supply intersection.
- What is the watershed to pond ratio?
- Is weed control a problem?
- What are the soil conditions? Clay or sandy?
- Are spillways adequate for high overflow conditions?
- Does water levels meet 50 year drought conditions?
- Is the pond of sufficient size?
If answers to these questions are positive then
the water source should be adequate for installation of a Dry
Hydrant supporting fire suppression.
INSTALLATION:
1. Installation should be done in accordance
to detailed plans, and maps showing water shed, and a 50 year
drought condition. This can usually be obtained thru local fire
departments, the Soil Conservation Department, or a state certified
engineer.
2. A back hoe should be used to dig a level
trench below the waters surface. A cleaner trench is obtained
when digging is started out in the pond and proceeds back to the
intended hydrant location. The trench should be approximately
2 ft. below drought level. A slight slope of 1-3 degrees can be
used, but all horizontal piping should be below the pond drought
level.
3. Assemble the underwater strainer to the horizontal lay
of pipe. Next assemble the vertical section of pipe making sure
ample length is available for final trimming. MAKE SURE STRAINER
HOLES ARE ALIGNED WITH VERTICAL RISER before gluing in place.
Allow assembled pipe to set. Slide pipe over into the trench starting
on the strainer end. This end will usually float, allowing ample
time to make minor adjustments for exact placement. Care should
be exercised to prevent stress on glued couplings or joints, when
lifting and lowering into the trench.
Make sure to use 6", Schedule-40 PVC pipe and fittings. Avoid
using pipe which may have been exposed to direct sunlight for
long periods of time, as it may have become brittle.
In cutting the PVC pipe us a medium tooth saw (a
carpenters hand saw works well). Never use a chain saw, as the
PVC curls left in the plumbing may become lodged in your pump
housing during initial pumping and testing of the installation.
This is especially true on small 2 1/2" portable pumps.
4. If an underwater support is required,
remove the two (2) plugs from the strainer. Insert a 1" outside
diameter pipe thru the first hole of the clamp band. After inserting
the 1" pipe or rod thru both walls of the 6" Dry Hydrant
pipe, bend the clamp band around the PVC pipe until the other
hole in the clamp band is in position. Continue to extend the
1" pipe until sufficient length is reached. Drive the 1"
pipe into the bottom of the pond using a pipe driver, or metal
fence post driver. Once the support is in place, position the
strainer so the pipe is at rest in the bottom of the trench. For
more detailed instructions see "Strainer Installation Instructions",
included with this product.
5. Back-fill the trench, starting at the
Dry Hydrant end and proceeding toward the water's edge. For convenience
it is best if dry dirt is used in the vicinity of the hydrant
head, as the head and below ground box must still be installed.
An area 2 ft. x 2 ft. should be left open in the trench near the
vertical riser. Position the Dry Hydrant head assembly approximately
3' below the ground surface. A 2x4" board is ideal for spanning
the open trench to determine this elevation. Saw off the excess
vertical pipe length and bond the head assembly in place. Care
should be taken to properly align this assembly. CAUTION: For
adequate clearance inside the hydrant box make sure all quick
connect adapters and caps, are assembled and checked for below
ground height prior to gluing the head assembly in place.
Position the flush mount box to accommodate the cam lever handles
of the flexible hose or hose adapter. Vertical placement can be
adjusted by slowly applying gravel in the bottom of the trench
under the box. This also acts as a drain for water that may collect
in the box during rainy weather or use. If the installation is
in a low area subject to standing water, a drain pipe may be laid
along side the 6" pipe, back to the pond. This pipe can be
as small as 1/2" diameter, but should have sufficient wall
strength to prevent collapsing. See diagram below:
In positioning the box raise the box top 1-2"
higher than ground level. This will allow for settling & prevent
a low spot which would hold water during rains.
6. After the area has dried to permit leveling,
landscape or sow grass seed to restore the area back to its natural
appearance. Hay or straw will serve to prevent erosion until vegetation
is present.
7. Install proper signs etc. to identify
the water source.
DESIGN INFORMATION:
1. To assure maximum flow it is best if
installations are kept as short as possible. We recommend all
installations be designed for a minimum of 1,000 GPM. As noted
previous all horizontal pipe should be below water level. Long
"Dry Pipe", will cause primer pump failure!
2. Hydrants should be installed in deep
water rather than the shallow end of a pond. This is necessary
due to the reach of a back hoe. On a shallow slope, the reach
would exceed the 10 - 12 ft. reach capability of most equipment.
3. Both a 45 degree or 90 degree configuration
can be used to install the dry hydrant. One may be a better choice
than the other depending upon terrain, site location, length,
and lift to the hydrant head.
4.
On short pipe installations of approximately 20 ft., a slight
variation can be made to significantly add of the draw-down depth
during drought conditions. This type of installation may also
be used on very small, but deep ponds where draw-down of the water
level may be significant. This design may also be used on short
installations, where rock prevents normal trenching used in allowing
the horizontal pipe to rest below water level.
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