Missing or Broken Water Filter Port / Adapter / Connector?
Here's How to Find Your Correct Part
1) Check: Is it a male or female part?
A male has threads on the outside, while a female part has the threads on the inside.
2) Check: Is the part tapered?
ie does it get wider / thinner or is it Parallel / straight. (This might not matter too much: If both sides / parts are small and plastic you can make up for any difference by using a lot of plumbers tape. But not if it's any bigger than half an inch)
3) Try to determine if it’s an NPT or BSP type
To do this properly you will need a thread gauge. (This might not matter too much if both sides are plastic. (Read more about mixing NPT and BSP parts)
4) Determine the size and use.
Read on - below.
Standard Housing Adapter Sizes - Male parts
This is where the male screwthread screws into a female port - typically on a water filter housing unit. It looks something like the image below.
Note that there is a difference between the actual/official diameter and the size it seems to be - ie what it looks like. This is because these are measured from the Thread valleys ie the lowest part of the thread.
- Actual diameter size: 1/4 inch BSP / Looks like 1/2 inch diameter
- Actual diameter size: 3/4 inch BSP / Looks like 1 inch diameter
- Actual diameter size: 1 inch BSP / Looks like 1.25 inch diameter
See all our male housing port connecters
Adapters for attaching Tubing to Tubing
This is where the part has two female ports / ends to accept a male pipe. It's sometimes called a "straight connector". It looks something like the image below.
Tube/Pipe Adapter / Connector Sizes
Standard Water filter tube sizes are almost always one of the following Outside Diameter (ie edge to edge) sizes.
- 1/4 inch / 6.4mm. This is the most common size
- 5/16ths inch / 8mm. This is less common. Used in Germany eg by German manufacturers like Brita
- 3/8ths inch / 9.6mm Often used with water filters with “spigots” ie male parts at the inlet / outlet
- 10mm More common with American water filters
- 12mm pipes - often found with water filter taps
It’s easy to find straight connectors ie to convert one size tube to the other. To see the ones we sell visit our spare parts page and use your browser search (eg Ctrl F) to find the right part.
Also see our Tube size combinations chart
Water Filter Tap Adapters
Many water filter taps accept a “male” pipe that fits into the base - see tube/pipe sizes above.
Some taps have a screw thread on their base/shank which accepts an adapter - into which the male tube fits.
Some taps have a threadless, straight-stem onto which a female adapter would slide which then accepts a male tube.
To find your part or combination of parts please visit our spare parts page and use your browser search (eg Ctrl F) to find the right part.
Water Supply Connectors
Saddle valves are the classic water filter connector that fit onto 15mm or 12mm copper pipe. 99% of these are for ¼ inch tubing.
"Washing machine" type adapters are easily converted to water filter tube formats.
Typically you would want a 15mm female part (to accept the 15mm tubing) coupled with a reducer to a ¼ inch female part (to accept the ¼ inch male tube Like this
or you could get a 15mm equal T piece from a plumbers merchants / BandQ / Homebase etc. These are easily converted to water filter tube formats eg using our 15mm to 6.4mm connector
Tapered vs Parallel Thread types
Tapered aka Dynamic threads are where the diameter/thickness changes eg it starts wide and becomes thinner. This helps seal as the parts go further in.
Tapered / Dynamic threads can be either on the male part (eg American / NPT standard) or Female (sometimes used on British BSP standard) But both standards can use either
Parallel threads are where the diameter stays the same
Using PTFE vs O Rings
On parallel threads you need to use O-rings / gaskets / banded seal rings to seal fittings at the end of the male - so that it presses against the face of the female, causing a seal
On tapered threads you should use PTFE ie plumbers tape or other sealant (you’d choose the right one depending on whether you’re dealing with metal or plastic parts)
Note: Tapered vs Parallel Thread introduces further codes
BSPT stands for BSP Tapered threads aka R-Thread
BSPP for BSP Parallel threads aka G-Thread
NPLTF stands for National Pipe Taper Fuel
NPS stands for National Pipe Straight Mechanical
Confusingly these NPT codes have alternates:
NPT can also stand for National Pipe Taper
NPS stands for National Pipe Straight