To determine the size of an angle valve, check the two connection sides separately: the thread to the wall and the connection to the tap or appliance. On a common angle valve these are ½ inch at the wall and ⅜ inch to the tap; other versions are possible. The inch figure is a connection designation and cannot be determined by simply converting a measured width. Note down both connections and the marking on the existing valve before you enquire about a replacement.
What exactly is an angle valve?
Technically, the angle valve is a shut-off valve: a fitting that opens or closes the flow in a water pipe in a controlled way. Shut-off valves with two connections come as ordinary straight-through valves – straight flow – or as angle valves, where inlet and outlet are at right angles to each other. These should be distinguished from three-way valves, which switch between two flow directions, such as three-way cocks. Whether a straight or an angled valve fits at the installation point simply depends on which direction the pipe comes from and where the hose leads afterwards.
What inch size is my angle valve?
Most angle valves in German households have two different connection sizes: a larger thread towards the wall and a smaller one towards the tap. This is no coincidence but the common standard size for which off-the-shelf connection hoses are also designed.
| Connection side | common inch size | what you connect it to |
|---|---|---|
| Wall side (inlet) | 1/2 inch | water pipe in the wall |
| Outlet to the tap | 3/8 inch | basin connection hose, WC cistern |
| Appliance outlet (combination angle valve) | 3/4 inch | washing machine or dishwasher |
A combination angle valve combines two outlets in one valve: a 3/8 inch outlet for the tap and an additional 3/4 inch appliance connection for a washing machine or dishwasher. If you only want to connect one appliance, choose a single appliance or oblique-seat valve with only one outlet instead.
Angle valves on the market are overwhelmingly made of brass, usually chrome-plated. Many versions – especially combination angle valves – also have a built-in non-return valve that prevents water from flowing back from the tap into the drinking water pipe. During installation, a wall rosette neatly covers the connection point in the wall.
What do you need to measure before buying?
Although inch sizes are standard dimensions, it is still worth checking the installed valve before ordering:
- Thread size at the wall connection – usually 1/2 inch; measure it on the old valve or look for the stamped size.
- Thread size at the outlet to the tap – the standard is 3/8 inch.
- For an appliance connection, also check the 3/4 inch thread.
- Design: is a simple angle valve with one outlet enough, or do you need the combination version with a second connection?
- Material and condition of the existing pipe – with copper or composite pipe directly in the wall, this also helps decide the right screw fitting.
Replacing an angle valve: what to know beforehand
The replacement itself takes place on the drinking water installation – which is why it is a job for a trade business, not for DIY. To speed up the enquiry and appointment, it helps to know or measure the following beforehand:
- Thread size at the wall connection and at the outlet to the tap (see table above).
- Whether a simple version is enough or the combination version with an additional appliance connection is needed.
- Material and visible condition of the existing pipe and fitting – copper, composite pipe or steel, firmly seated or visibly corroded.
- Whether the main water supply or a closer stopcock can be reached to depressurise the pipe.
With this information, the installer can assess the valve and the work involved in advance instead of improvising on site.
Frequently asked questions
How do I determine the size of my angle valve?
First look for a stamped size on the valve. If there is none, comparing the connections helps: the larger thread sits towards the wall, usually ½ inch, which corresponds to DN 15. The smaller one with ⅜ inch sits towards the tap. If the valve has a third, larger outlet with ¾ inch, it is a combination angle valve for a washing machine or dishwasher. If in doubt, send us a photo of the old valve with your enquiry.
Is the connection to the tap ⅜ or ½ inch?
Towards the tap ⅜ inch is usual; ½ inch is the size towards the wall. On our angle valves, the tap side is a ⅜″ (10 mm) compression fitting with a brass cone. If you connect the tap and valve with a hose, flexible hoses with ⅜ inch connections fit; whether you need male/female (AG/IG) or female/female (IG/IG) depends on the threads on the tap and valve.
Are angle valves standardised?
The connection threads are standard inch sizes, and ½ inch to the wall with ⅜ inch to the tap is the common standard size, for which off-the-shelf connection hoses are also designed. How deep the wall connection sits, on the other hand, varies from one installation point to another; our ½″ angle valve and the combination angle valve have a length adjustment for this. Still, check the existing valve before ordering.
Suitable products and collection in Hagen
You will find angle valves and combination angle valves from our range in the collection Angle valves & connection fittings. We give prices on enquiry; add the right valve to your enquiry list and we will get back to you with availability and a date. Collection is possible at our warehouse in Hagen, shipping by arrangement.