Technical Information

Darcy's Law
Blue Diamond Pipe Specifications
Flowtech™ Drainage Systems
Study from StyroChem and Resirene

Darcy's Law

A law describing the rate of flow of water through porous media. (Named for Henry Darcy of Dijon, who formulated it in 1856 from extensive work on the flow of water through sand filter beds.) As formulated by Darcy the law is:

Q = k*S*(H+e)/e
              
where
Q is the volume of water passed in unit time,
S is the area of the bed,
e is the thickness of the bed,
H is the height of the water on top of the bed, and
"k is a coefficient depending on the nature of the sand" and 
for cases where the pressure "under the filter is equal to 
the weight of the atmosphere."

Generalization for three dimensions: The rate of viscous flow of water in isotropic porous media is proportional to, and in the direction of, the hydraulic gradient.
Generalization for other fluids: The rate of viscous flow of homogeneous fluids through isotropic porous media is proportional to, and in the direction of, the driving force.

Blue Diamond Corrugated Polyethylene Pipe Specifications 3399 Tates Creek Road, Suite 110 Lexington, KY 40502 859.224.0415 859.224.0543 fax www.bdiky.com

MATERIAL	DIAMETER	ELONGATION	PIPE STIFFNESS
4" SINGLE WALL	4.0"	10%	24 PII @ 5%
6" SINGLE WALL	6.0"	10%	24 PII @ 5%

Specifications

ASTM F405: STANDARD SPECIFICATION FOR CORRUGATED POLYETHYLENE PIPE AND FITTINGS

LEACHED BED PIPE PERFORATIONS: 2 ROWS ¼" to ¾" DIAMETER HOLES AT MAXIMUM 5" CENTERS

ASTM D1248 (GRADE PE 33, CLASS C): STANDARD SPECIFICATIONS FOR PE PLASTIC COMPOUNDS HAVING HIGHER CELL CLASSIFICATIONS ARE ACCEPTABLE PROVIDING PRODUCT REQUIREMENTS ARE MET

Typical Properties
Property	Test Procedures	Units
Density (3)	ASTM D1505	0.941 - 0.955 gm/cc
Melt Index (2)	ASTM D1238	1.0 to 0.4gm/10min
Flexural Modulus (4)	ASTM D790	80,000 - 110,000 psi
Tensile Strength Yield)(4)	ASTM D638	3000 - 3500 psi
UV Stabilizer (C or E)	ASTM D1603	>2%
Ultimate Elongation	ASTM D638	>400%

Flowtech™ Drainage Systems
	Gravel System w/4" pipe	Flowtech™ System w/4" pipe
clean/dust free		√
light weight		√
easy to install		√
1.6 times effective than gravel		√
versatile	√	√
faster installation		√
less installation damage to existing lawn		√
no large equipment needed		√
reduce labor		√
no compaction		√
consistent shape		√
engineered flow channels		√
dramatically increase flow rate		√
gravel clean-up and removal	√

General Durability and Resistance to Degradation
Polystyrene is a very inert, chemical resistant and biologically resistant material. It is inert to chemical reactions and absorption of essentially all aqueous media. Its only degrading environments are essentially oils and solvents. Undisturbed polystyrene foams exposed to biologically rich soils for many decades exhibit negligible degradation.

Shelf Life
The useful lifetime of polystyrene foam is essentially unlimited, at least many decades, in absence of long-term exposure to sunlight, oils and solvents.

Termites, Ants and Rodents
Polystyrene cannot be digested or metabolized by animals, insects or microorganisms. Hence it is not a source of food and is not consumed by pests. Such pests could presumably burrow through polystyrene foam if there is an incentive such as another food source or shelter to be reached.

Chemical Absorption
The polystyrene foam used for dunnage, insulation and load bearing applications is essentially a closed cell structure. Therefore liquids are unable to permeate and saturate the foam through open channels, as with water in a sponge.

The polystyrene itself which makes up the foam structure is highly inert to the absorption of aqueous, including acid and bases, and to contaminants that are readily soluble in water, uncontaminated by organics, salts and trace metals.

Polystyrene can absorb significant amounts of oils, fats and solvents, and may be significantly degraded in such environments.

Temperature Stability
The use temperature range of polystyrene foam widely exceeds the range of ambient temperatures in all climates. The upper limit for retention of good mechanical properties is about 170°F for prolonged exposure.

There is no significant loss of strength at very low temperatures as with rubbery materials. Therefore polystyrene foam remains a good load bearing and insulating material at far sub-zero temperatures. It is used as an insulating material for cold storage installations at temperatures of about -40°F.

Life Span
Expanded polystyrene is a highly stable compound. The expected life span is indefinite.
The product will last for well over 100 years