Residual Head

2017-10-03T07:39:28Z

Joceil.infante: Created page with "The difference between the calculated energy losses through the pipe system (from the drain inlet to the point of discharge) and the available disposable head.<ref> ASPE Stand..."

Roof outlet

2017-10-03T07:38:07Z

Joceil.infante:

In other countries, roof outlet is also called drain outlet or drain inlet.

In [[Siphonic Roof Drainage]], roof outlet is the drain “neck” of a siphonic roof drain configured to connect to the tailpiece with a standard coupling device.
Roof outlet receives the rainwater from roof areas or a gutter before it leads to the pipe system and finally to the discharge point.<ref>ASPE Standard 45</ref>

As defined in BS EN 1253-1:2003, it is a non-trapped gully, used in a roof (see figure below).

[[File:Gully-Roof-Outlet.jpeg]]
'''Grating''' – removable component with apertures which permit the discharge of wastewater. <br clear=all>
'''Body''' – part of a gully below or in the floor, ground or roof on which the grating/ frame/ extension is mounted, and to which pipework is connected. <br clear=all>
'''Membrane''' – watertight finished layer for floors affixed to the flange by bonding and or by means of a clamping ring. <br clear=all>
'''Connecting flange''' – separate or an integral part or of a body or of an extension which receives a membrane or sheet floor covering. <ref> BS EN 1253-1:2003 </ref>

== References ==

Roof outlet

2017-10-03T07:37:45Z

Joceil.infante: Created page with "In other countries, roof outlet is also called drain outlet or drain inlet. In Siphonic Roof Drainage, roof outlet is the drain “neck” of a siphonic roof drain config..."

In other countries, roof outlet is also called drain outlet or drain inlet.

In [[Siphonic Roof Drainage]], roof outlet is the drain “neck” of a siphonic roof drain configured to connect to the tailpiece with a standard coupling device.
Roof outlet receives the rainwater from roof areas or a gutter before it leads to the pipe system and finally to the discharge point.<ref>ASPE Standard 45</ref>

As defined in BS EN 1253-1:2003, it is a non-trapped gully, used in a roof (see figure below).<ref> BS EN 1253-1:2003 </ref>

[[File:Gully-Roof-Outlet.jpeg]]
'''Grating''' – removable component with apertures which permit the discharge of wastewater. <br clear=all>
'''Body''' – part of a gully below or in the floor, ground or roof on which the grating/ frame/ extension is mounted, and to which pipework is connected. <br clear=all>
'''Membrane''' – watertight finished layer for floors affixed to the flange by bonding and or by means of a clamping ring. <br clear=all>
'''Connecting flange''' – separate or an integral part or of a body or of an extension which receives a membrane or sheet floor covering. <ref> BS EN 1253-1:2003 </ref>

== References ==

Rainwater

2017-10-03T07:22:49Z

Joceil.infante:

*Water resulting from natural precipitation that has not been deliberately contaminated.<ref> BS EN 12056-5 Gravity drainage systems inside buildings </ref>
<ref>DIN 1989-1:2001-10 Rainwater harvesting systems</ref>

== References ==

Rainwater line

2017-10-03T07:22:26Z

Joceil.infante: Created page with "*Supply drainage, overflow and emptying lines of a rainwater harvesting system <ref>DIN 1989-1:2001-10 Rainwater harvesting systems</ref> == Reference =="

*Supply drainage, overflow and emptying lines of a rainwater harvesting system <ref>DIN 1989-1:2001-10 Rainwater harvesting systems</ref>

== Reference ==

Rainwater

2017-10-03T07:20:55Z

Joceil.infante: Created page with "*Water resulting from natural precipitation that has not been deliberately contaminated.<ref> BS EN 12056-5 Gravity drainage systems inside buildings </ref> <ref>DIN 1989-1:20..."

Pipe flow

2017-10-03T07:07:48Z

Joceil.infante:

Siphonic drainage systems falls under the category of '''Pipe flow''', while gravity drainage systems (eg. horizontal pipes with gradient, open drains etc) falls under the category of [[Open Channel Flow]].

Pipe flow, a branch of hydraulics and fluid mechanics, is a type of liquid flow within a closed conduit (conduit in the sense of a means of containment). The other type of flow within a conduit is open channel flow. Pipe flow does not have a free surface which is found in [[Open Channel Flow]]. Pipe flow, being confined within closed conduit, does not exert direct atmospheric pressure, but does exert hydraulic pressure on the conduit.<ref> Open Channel Hydraulics by Chow </ref>

Energy in pipe flow is expressed as head and is defined by the [[Bernoulli's Equation]]. In order to conceptualize head along the course of flow within a pipe, diagrams often contain a hydraulic grade line. Pipe flow is subject to frictional losses as defined by the [[Darcy-Weisbach Equation]].<ref> https://en.wikipedia.org/wiki/Pipe_flow </ref>
<br clear = all>
[[File:Open-channel-flow.jpg]]

== References ==

Poisson's ratio

2017-10-03T07:05:10Z

Joceil.infante:

Poisson ratio is one of the important criteria to be considered in pipe selection where the system may be subjected to sub-atmospheric pressure (e.g. [[Siphonic drainage systems]]). In general, a lower value in Poisson ratio provides better strength against collapse of pipe due to sub-atmospheric pressure.

In evaluating the limiting or maximum pressures, forces and deflections on plastic pipe, fittings and components covered by this standard, the material properties listed below are assumed at an operating temperature of 20°C (68°F).<ref> ASPE Standard 45 </ref>

{| class="wikitable"
!colspan="6"|Material Properties at an Operating Temperature of 20°C (68°F)
|-
|'''Property/ Material'''
|'''Tensile Modulus of Elasticity'''
|'''Creep Modulus'''
|'''Poisson’s Ratio'''
|'''Rate of Thermal Expansion'''
|-
|Symbol
|<math>E_t</math>
|<math>E_c</math>
|<math>\mu</math>
|<math>C_{tx}</math>
|-
|Units
|Mpa(psi)
|Mpa(psi)
|dimensionless
|cm/cm/°C (ft/ft/°F)
|-
|ABS
|2,206 (320,000)
|rowspan="2"|Varies (refer to 8.2.2)
|0.35
|10.3 E-5 (5.7 E-5)
|-
|HPDE
|862 (125,000)
|0.45
|18.0 E-5 (10.0 E-5)
|-
|PVC
|2,827 (410,000)
|0.35
|5.2 E-5 (3.0 E-5)
|-
|Test Method
|ASTM D638
|ISO 899
|ASTM E132
|ASTM D696
|}

'''Material Properties of Thermoplastic Pipe'''<br clear=all>
Creep modulus varies by plastic material, temperature, age, and time of loading ('''TI'''). The time of loading is defined as the period of time a plastic siphonic piping system is expected to be operating at the relevant pressure. Once the storm event is over and the system drains, the material recovers and assumes its original tensile modulus (i.e., '''EC(TI= 0) = Et'''). However, the material elastic modulus and creep modulus also typically decrease with age. Refer to pipe manufacturer data for the appropriate creep modulus value.

Calculation of allowable pressure <math>(Pa)</math>: The minimum required pipe wall thickness <math>(t)</math> shall be based on '''Equations 8.1''' and '''8.2''' in '''Table 8.2''' and the mechanical and dimensional properties of the pipe material evaluated. '''Equations 8.1''' and '''8.2''' apply for a long cyclindrical tube of length '''L''' and wall thickness '''t''' under uniform external pressure with <math>(R/t) /> 10</math>.

{| class="wikitable"
!colspan="6"|Table 8.2 Pipe Wall Thickness Calculations
|-
|'''Equation 8.1''' <br clear=all>
When, <math> L \ge 4.9R \sqrt{\frac{R}{t}}</math>
|'''Equation 8.2''' <br clear=all>
When <math> L \le 4.9R \sqrt{\frac{R}{t}}</math>
|-
|<math>P_{cr}= \frac{E_c}{3(1-\mu^2)} \Bigg[ \frac{t}{R} \Bigg]^3</math>
|<math>P_{cr}= 0.807 \Bigg[ \frac{E_c t^2}{LR} \Bigg] \Bigg[ \Big( \frac{1}{1-\mu^2} \Big) \Big( \frac{t}{R} \Big)^2 \Bigg] ^{0.25} </math>
|-
|When, <math>L \ge 4.9R \sqrt{\frac{R}{t}}</math>
|When, <math>L \le 4.9R \sqrt{\frac{R}{t}}</math>
|}
<br clear=all>
The parameter <math>E_c</math> is the elastic creep modulus at the specified time of loading. The allowable pressure <math>(Pa)</math> shall be the calculated critical buckling pressure divided by the factor of safety ('''FS''') as in equation below:

'''Equation 8.3:'''
<br clear=all>

<math> P_a = \frac{P_cr}{FS} \ge 14.7 psia (1.0 bar)</math>
<br clear=all>

*'''Poisson's ratio''' is the ratio of the relative contraction strain (or transverse strain) normal to the applied load - to the relative extension strain (or axial strain) in the direction of the applied load <ref>http://www.engineeringtoolbox.com/poissons-ratio-d_1224.html</ref>

Poisson's Ratio can be expressed as;
μ = - εt / εl
where
μ = Poisson's ratio
εt = transverse strain
εl = longitudinal or axial strain

Strain can be expressed as;
ε = dl / L
where
dl = change in length (m, ft)
L = initial length (m, ft)
For most common materials the Poisson's ratio is in the range 0 - 0.5.
μ = Poisson’s Ratio (dimensionless)

* '''Poisson's ratio''' describes the relative change of the lateral dimension of an object when the load is applied on the longitudinal direction and vice versa. (See reference video link [https://www.youtube.com/watch?v=hBnzrBhnzVo])

== References ==

Poisson's ratio

2017-10-03T06:57:02Z

Joceil.infante:

Poisson ratio is one of the important criteria to be considered in pipe selection where the system may be subjected to sub-atmospheric pressure (e.g. [[Siphonic drainage systems]]). In general, a lower value in Poisson ratio provides better strength against collapse of pipe due to sub-atmospheric pressure.

In evaluating the limiting or maximum pressures, forces and deflections on plastic pipe, fittings and components covered by this standard, the material properties listed below are assumed at an operating temperature of 20°C (68°F).<ref> ASPE Standard 45 </ref>

{| class="wikitable"
!colspan="6"|Material Properties at an Operating Temperature of 20°C (68°F)
|-
|'''Property/ Material'''
|'''Tensile Modulus of Elasticity'''
|'''Creep Modulus'''
|'''Poisson’s Ratio'''
|'''Rate of Thermal Expansion'''
|-
|Symbol
|<math>E_t</math>
|<math>E_c</math>
|<math>\mu</math>
|<math>C_{tx}</math>
|-
|Units
|Mpa(psi)
|Mpa(psi)
|dimensionless
|cm/cm/°C (ft/ft/°F)
|-
|ABS
|2,206 (320,000)
|rowspan="2"|Varies (refer to 8.2.2)
|0.35
|10.3 E-5 (5.7 E-5)
|-
|HPDE
|862 (125,000)
|0.45
|18.0 E-5 (10.0 E-5)
|-
|PVC
|2,827 (410,000)
|0.35
|5.2 E-5 (3.0 E-5)
|-
|Test Method
|ASTM D638
|ISO 899
|ASTM E132
|ASTM D696
|}

Calculation of allowable pressure <math>(Pa)</math>: The minimum required pipe wall thickness <math>(t)</math> shall be based on '''Equations 8.1''' and '''8.2''' in '''Table 8.2''' and the mechanical and dimensional properties of the pipe material evaluated. '''Equations 8.1''' and '''8.2''' apply for a long cyclindrical tube of length '''L''' and wall thickness '''t''' under uniform external pressure with <math>(R/t) /> 10</math>.

{| class="wikitable"
!colspan="6"|Table 8.2 Pipe Wall Thickness Calculations
|-
|'''Equation 8.1''' <br clear=all>
When, <math> L \ge 4.9R \sqrt{\frac{R}{t}}</math>
|'''Equation 8.2''' <br clear=all>
When <math> L \le 4.9R \sqrt{\frac{R}{t}}</math>
|-
|<math>P_{cr}= \frac{E_c}{3(1-\mu^2)} \Bigg[ \frac{t}{R} \Bigg]^3</math>
|<math>P_{cr}= 0.807 \Bigg[ \frac{E_c t^2}{LR} \Bigg] \Bigg[ \Big( \frac{1}{1-\mu^2} \Big) \Big( \frac{t}{R} \Big)^2 \Bigg] ^{0.25} </math>
|-
|When, <math>L \ge 4.9R \sqrt{\frac{R}{t}}</math>
|When, <math>L \le 4.9R \sqrt{\frac{R}{t}}</math>
|}
<br clear=all>
The parameter <math>E_c</math> is the elastic creep modulus at the specified time of loading. The allowable pressure <math>(Pa)</math> shall be the calculated critical buckling pressure divided by the factor of safety ('''FS''') as in equation below:

'''Equation 8.3:'''
<br clear=all>

<math> P_a = \frac{P_cr}{FS} \ge 14.7 psia (1.0 bar)</math>
<br clear=all>

*'''Poisson's ratio''' is the ratio of the relative contraction strain (or transverse strain) normal to the applied load - to the relative extension strain (or axial strain) in the direction of the applied load <ref>http://www.engineeringtoolbox.com/poissons-ratio-d_1224.html</ref>

Poisson's Ratio can be expressed as;
μ = - εt / εl
where
μ = Poisson's ratio
εt = transverse strain
εl = longitudinal or axial strain

Strain can be expressed as;
ε = dl / L
where
dl = change in length (m, ft)
L = initial length (m, ft)
For most common materials the Poisson's ratio is in the range 0 - 0.5.
μ = Poisson’s Ratio (dimensionless)

* '''Poisson's ratio''' describes the relative change of the lateral dimension of an object when the load is applied on the longitudinal direction and vice versa. (See reference video link [https://www.youtube.com/watch?v=hBnzrBhnzVo])

== References ==

Poisson's ratio

2017-10-03T06:52:26Z

Primary System (Siphonic system)

2017-10-03T01:36:42Z

Joceil.infante:

As a safety precaution, it is recommended to provide overflow systems to gutters or roofs where risk of overflow (due to blockage or extreme rainfall) cannot be tolerated.

[[Overflow]] systems can generally be of 2 types;
#Overflow weirs
#Secondary pipe systems.

In the case of roofs with secondary piped overflow systems, the primary system refers to the main system that is designed to work most of the time while the secondary system acts as a backup for either blockage or for extreme rainfall that exceeds the design capacity of the primary system.

'''Primary and secondary siphonic systems''' should operate completely independently of each other. The primary system can be designed to deal with all lower return period of storms up to specified rainfall intensity. Secondary system will deal with more intense storms up to the maximum design intensity for the scheme. This can be achieved by preventing flow from entering the outlets of the secondary system until water levels in the gutter or flat roof exceed a certain limit.<ref> BS 8490:2007 Guide to siphonic roof drainage system </ref>

== References ==

[[Category:Siphonic Drainage System]]

Precipitation

2017-09-29T08:58:37Z

Joceil.infante:

Rainfall occurs due to precipitation.

In meteorology, '''precipitation''' is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and "precipitates". Thus, fog and mist are not precipitation but suspensions, because the water vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called "showers." <ref> https://en.wikipedia.org/wiki/Precipitation </ref>

'''Precipitation''' is any type of water that forms in the Earth's atmosphere and then drops onto the surface of the Earth.
Water vapor, droplets of water suspended in the air, builds up in the Earth's atmosphere. Water vapor in the atmosphere is visible as clouds and fog. Water vapor collects with other materials, such as dust, in clouds.
Precipitation condenses, or forms, around these tiny pieces of material, called cloud condensation nuclei (CCN).
Clouds eventually get too full of water vapor, and the precipitation turns into a liquid (rain) or a solid (snow).
Precipitation is part of the water cycle. Precipitation falls to the ground as snow and rain. It eventually evaporates and rises back into the atmosphere as a gas. In clouds, it turns back into liquid or solid water, and it falls to Earth again. People rely on precipitation for fresh water to drink, bathe, and irrigate crops for food.
The most common types of precipitation are rain, hail, and snow. <ref> https://www.nationalgeographic.org/encyclopedia/precipitation/ </ref>
<br clear=all>
[[File:Precipitation_Water_cycle.jpeg|500px]]
<br clear=all>

== References ==

2017-09-29T02:21:20Z

Joceil.infante: