Air admittance valve - Revision history

Designing Buildings at 07:40, 14 July 2021

2021-07-14T07:40:12Z

← Older revision		Revision as of 07:40, 14 July 2021
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	* Soakaway.		* Soakaway.
	* Sustainable urban drainage systems SUDS.		* Sustainable urban drainage systems SUDS.
		+	* Vacuum breaker.

	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Water]] [[Category:Products_/_components]]		[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Water]] [[Category:Products_/_components]]

Designing Buildings at 07:35, 12 November 2020

2020-11-12T07:35:25Z

← Older revision		Revision as of 07:35, 12 November 2020
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	* Sustainable urban drainage systems SUDS.		* Sustainable urban drainage systems SUDS.

−	[[Category:~~Water~~]] [[Category:~~Products_/_components~~]] [[Category:DCN_Product_Knowledge]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Water]] [[Category:Products_/_components]]

Designing Buildings at 09:32, 10 June 2019

2019-06-10T09:32:34Z

Designing Buildings: Created page with "Drainage systems in buildings must be vented to allow the escape of gases and odours, to allow the release of pressure in front of flowing waste and to allow air to re-enter the ..."

2019-06-10T09:28:11Z

Created page with "Drainage systems in buildings must be vented to allow the escape of gases and odours, to allow the release of pressure in front of flowing waste and to allow air to re-enter the ..."

New page

Drainage systems in buildings must be vented to allow the escape of gases and odours, to allow the release of pressure in front of flowing waste and to allow air to re-enter the system following the passage of waste.

This can be achieved by connecting waste pipes to a soil vent stack (SVP). SVPs are often seen running vertically on the outside of domestic properties, and have an open vent above eaves level allowing air into and out of the system without odours or gases causing nuisance. For more information see: Soil vent stack.

Where it is not practical to connect waste pipes to a traditionally-vented soil vent stack, an air admittance valve (AAV, sometimes referred to as a Durgo valve) may be used to prevent a siphoning affect from occurring, allowing free flow of waste by gravity, and preventing gases entering the property from the drainage system.

This may be necessary for example when new appliances are installed in an existing building and there is no clear route to the soil vent stack, to close washing machine standpipes, for island units, to reduce the amount of pipework penetrating the roof or walls of a building and so on.

Air admittance valves open to allow air into the system when there is negative pressure, and close under positive pressure preventing gasses from entering the system. This maintains trap seals and siphons within the system, but does not relieve positive pressure within the system.

Approved document H of the building regulations sets out the circumstances in which air admittance valves may be used, and requires that:

* They comply with BS EN 12380:2002: Air admittance valves for drainage systems. Requirements, test methods valuation of conformity.
* They do not adversely affect the amount of ventilation necessary for below ground sewers.
* They are located in areas with adequate ventilation.
* They have clear access for maintenance and for the removal of blockages.
* They are not used outside or in dust laden atmospheres.
* Where there is no open vent on the system or connected drains, alternative arrangements are made to relieve positive pressures (as air admittance valves only relieve negative pressure, not positive pressure.

NB When installing drainage and ventilation pipework in high-rise buildings, traditional design standards dictate that a secondary ventilation stack is used to overcome air pressure changes. However, products such as the Polypipe Terrain P.A.P.A® and Pleura valves are a proven alternative. The P.A.P.A® (positive air pressure attenuation) valve is designed to react to and attenuate positive pressure transience within the drainage stack of high-rise developments providing a suitable venting solution for any multi-storey building.

For more information see: Secondary Ventilation Stacks in Tall Buildings.

= Related articles on Designing Buildings Wiki =

* Drainage.
* Drainage stack.
* Fabricated drainage stacks.
* Rainwater downpipe.
* Sanitary pipework.
* Secondary Ventilation Stacks in Tall Buildings.
* Sewer construction.
* Soil vent pipe.
* Soakaway.
* Sustainable urban drainage systems SUDS.

[[Category:Water]] [[Category:Products_/_components]]

← Older revision		Revision as of 09:32, 10 June 2019
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	This can be achieved by connecting waste pipes to a soil vent stack (SVP). SVPs are often seen running vertically on the outside of domestic properties, and have an open vent above eaves level allowing air into and out of the system without odours or gases causing nuisance. For more information see: Soil vent stack.		This can be achieved by connecting waste pipes to a soil vent stack (SVP). SVPs are often seen running vertically on the outside of domestic properties, and have an open vent above eaves level allowing air into and out of the system without odours or gases causing nuisance. For more information see: Soil vent stack.

−	Where it is not practical to connect waste pipes to a traditionally-vented ~~soil vent stack~~, an air admittance valve (AAV, sometimes referred to as a Durgo valve) may be used ~~to prevent a siphoning affect from occurring, allowing free flow of waste by gravity, and preventing gases entering the property from the drainage system~~.	+	Where it is not practical to connect waste pipes to a traditionally-vented SVP, an air admittance valve (AAV, sometimes referred to as a Durgo valve) may be used.

−	This may be necessary for example when new appliances are installed in an existing building and there is no clear route to the ~~soil vent stack~~, to close washing machine standpipes, for island units, to reduce the amount of pipework penetrating the roof or walls of a building and so on.	+	This may be necessary for example when new appliances are installed in an existing building and there is no clear route to the SVP, to close washing machine standpipes, for island units, to reduce the amount of pipework penetrating the roof or walls of a building and so on.

−	Air admittance valves open to allow air into the system when there is negative pressure, and close under positive pressure preventing gasses from entering the ~~system~~. This maintains trap seals and siphons within the system, but does not relieve positive pressure ~~within the system~~.	+	Air admittance valves open to allow air into the system when there is negative pressure, and close under positive pressure preventing gasses from entering the building. This maintains trap seals and siphons within the system, but does not relieve positive pressure.

	Approved document H of the building regulations sets out the circumstances in which air admittance valves may be used, and requires that:		Approved document H of the building regulations sets out the circumstances in which air admittance valves may be used, and requires that:

−	* They comply with BS EN 12380:2002: Air admittance valves for drainage systems. Requirements, test methods valuation of conformity.	+	* They comply with BS EN 12380:2002: Air admittance valves for drainage systems. Requirements, test methods and valuation of conformity.
	* They do not adversely affect the amount of ventilation necessary for below ground sewers.		* They do not adversely affect the amount of ventilation necessary for below ground sewers.
	* They are located in areas with adequate ventilation.		* They are located in areas with adequate ventilation.
	* They have clear access for maintenance and for the removal of blockages.		* They have clear access for maintenance and for the removal of blockages.
	* They are not used outside or in dust laden atmospheres.		* They are not used outside or in dust laden atmospheres.
−	* Where there is no open vent on the system or connected drains, alternative arrangements are made to relieve positive pressures (as air admittance valves only relieve negative pressure, not positive pressure.	+	* Where there is no open vent on the system or connected drains, alternative arrangements are made to relieve positive pressures (as air admittance valves only relieve negative pressure, not positive pressure).

	NB When installing drainage and ventilation pipework in high-rise buildings, traditional design standards dictate that a secondary ventilation stack is used to overcome air pressure changes. However, products such as the Polypipe Terrain P.A.P.A® and Pleura valves are a proven alternative. The P.A.P.A® (positive air pressure attenuation) valve is designed to react to and attenuate positive pressure transience within the drainage stack of high-rise developments providing a suitable venting solution for any multi-storey building.		NB When installing drainage and ventilation pipework in high-rise buildings, traditional design standards dictate that a secondary ventilation stack is used to overcome air pressure changes. However, products such as the Polypipe Terrain P.A.P.A® and Pleura valves are a proven alternative. The P.A.P.A® (positive air pressure attenuation) valve is designed to react to and attenuate positive pressure transience within the drainage stack of high-rise developments providing a suitable venting solution for any multi-storey building.
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	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =

		+	* Approved document H.
	* Drainage.		* Drainage.
	* Drainage stack.		* Drainage stack.
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	* Sustainable urban drainage systems SUDS.		* Sustainable urban drainage systems SUDS.

−	[[Category:Water]] [[Category:Products_/_components]]	+	[[Category:Water]] [[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]