Discussion in 'Plumbers' Talk' started by MarkyBoy, May 12, 2004.
Does anyone please know the difference between a Surrey flange and a York flange ?
I just had a quick look around the web and came up with the following stuff for you....
Cavitation and air in pumped showers
The nearer the pump is to the supplies, the better it will operate (and obviously a two-chamber pump can be put nearer to the supply). This is because a pump may be capable of producing a very high pressure, but can only "suck" at one atmosphere before a vacuum is created and performance will not increase. Even before this, "cavitation" (tiny vacuum or dissolved air bubbles) will start at the impeller blades, and this is very bad for the pump. Water from the rising main contains dissolved air, and heating it up encourages it to liberate this. It is therefore a good idea to connect a shower pump to a hot water cylinder with a "Surrey flange" or an "Essex flange", which has a short dip-tube to avoid trapping the liberated air rolling up the sides of the cylinder. (A Surrey flange fits into the top of the cylinder and has an additional output for the existing connections an Essex flange is a dip-tube only and goes into a new hole made in the cylinder.) Surrey/Essex flanges will also help to avoid interaction between the pump and other hot water consumers.
Advantages of Surrey Flange
The Surrey Flange is designed to provide an independent hot water supply from an "Air Free" position within the cylinder and dramatically reduces air surging, noise and temperature variations.
Vented Surrey Flange
The new air vent automatically purges the shower circuit preventing an accumulation of air in the hot water shower feed (Patent applied for).
The silicone rubber vent valve automatically releases air and prevents back feed of aerated hot water.
15mm Surrey Flange:
To suit cylinder outlet of 3/4" BSP Female (by using a 1" to 3/4" adaptor this size can be used on 1" cylinder outlet).
Weight: 280g Length:165mm Draw-off tube:15mm dia
Outlet size: 1/2" BSP Female
22mm Surrey Flange:
To suit cylinder outlet of 1" BSP Female
Weight: 385g Length: 165mm Draw-off tube: 22mm dia Outlet size: 3/4" BSP Female
The York Flange is a modified version of the 22mm Surrey Flange, but has an adaptor supplied to suit cylinders with 1" BSP Male outlets.
Weight: 500g Length: 165mm Draw-off tube: 55mm dia Outlet size: 3/4" BSP
above is from http://www.diynot.com/forums and http://www.kbb2000.net/watermill/flange.htm
Good Job Deelow. Thankyou very much. I need a 22mm outlet and as my hot water cylinder has a 1" male outlet it looks like the York flange suits my purpose. IThere is no way I would consider using an Essex and cutting into the cylinder.
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