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Broken Connectors

Missing or Broken Water Filter Port / Adapter / Connector?

Here's How to Find Your Correct Part


Replacement Adapter Guide

BSP vs NPT Types

Some General Terms Used for Screw Threads

Replacing Housing Adapters / Ports

Replacing Water Filter Tap Connectors

Replacing Water Supply Connectors

More about Tube Sizes

Chart of Tube Size Adapters Combinations

Our replacment adapter service


Replacement Adapter Guide

If you have a lost or broken water filter part and need a replacement here’s how to determine the right part you need to replace it with.

First: What was the Broken Part Used for?

Typical Broken Water Filter Adapter / Port Uses:

Attaching a tube into a housing unit or similar receptacle

Connecting one tube to another (possibly changing the size)

Adapters for attaching a tube etc into a housing unit


Is it a Screwthread Type?

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.

male vs female adapter

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)

 Tapered Thread Adapter

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)

 Thread measuring guage

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.

Male screwthread adapter


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.

Size Guide

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

Female to female adapter

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



Related information

Our replacement adapter service

Broken Port / Adapter / Connector? Help Finding Your Replacement

Adapter size to size chart

Replacement Adapter Help

BSP vs NPT Types

Some General Terms Used for Screw Threads

Replacing Housing Adapters / Ports

Replacing Water Filter Tap Connectors

Replacing Water Supply Connectors

More about Tube Sizes

Chart of Tube Size Adapters Combinations