What size is my Nitrous Hose?

Looking to buy a new nitrous line or have a system and need to know what line you are using?

There are a few types of nitrous hose available but these can be broken down to a few select hose ends as follows:

Nylon Hoses - This hose is a simple nylon hose, it has no braiding and typically comes in low pressure and high pressure formats. Only high pressure is used from cylinder to solenoids, low pressure for outlets to injectors etc. Colours available are Red, Blue & Black.

4mm Nylon -  Used on WON systems this size was once used as a feed hose but has not been used for over 10 years superceeded by the 5mm hose. This is now mainly used for outlet applications to injectors/foggers. To determine if you are using this hose you can use the following points to confirm:

1. Hose Diameter = 4mm [ 0.157"  ] Outside Diamter

2. Hose Nut = 8mm [ 0.315" ] across the flats

3. If no hose or nut is available you can determine from the hose fitting. On a male fitting this will be 8mm [ 0.315" ]  Outside diameter, on an internal fitting it will have a 7mm [ 0.275" ] Inside diamter (at the threads)

4. Uses an M8 x 1 thread connection.

5mm Nylon - As per the 4mm hose this is non-braided but is mainly used as the feed hose on 150Bhp WON systems. To determine if you are using this use the following points:

1. Hose Diameter = 5mm [ 0.197" ] Outside Diamter

2. Hose Nut = 10mm [ 0.394" ] across the flats

3. If no hose or nut is available you can determine from the hose fitting. On an internal fitting it will have a 9mm [ 0.354" ] Inside diamter (at the threads) External fittings have never been used by WON for this type.

4. Uses an M10 x 1 thread connection.

 Braided Hoses - These come in a few styles & sizes, the most common is a PTFE based inner hose covered with a Stainless Steel outer braid. There are a few other braiding materials being used however they all typically maintain the same connection sizes.

1/8th Braided -  Used mainly in the UK using JIC connections the hose has been superceeded in WON products by the 4AN braided hose for at least 8 years. Anything later is likely to be a different size. To determine if you are using this use the following points:

1. Hose Diameter = 6.35mm [ 0.25" ] Outside Diamter

2. Hose Swivel Nut = 13.35mm [ 0.525" ] across the flats

3. If no hose or nut is available you can determine from the hose fitting. On a male fitting this will be approx 9.7mm [ 0.381" ]

4. Uses a 1/8th BSPP thread connection.

5. Hose connection uses a male cone inside the female swivel, adapters must use male thread with female taper.

3AN Braided - A USA spec hose & connection the 3AN braided is similar in size to the UK 1/8th braided the main difference being the connection threads and end styles. Used for lower power applications on US systems but more common outlet pipework on US systems from Solenoids to Foggers. 

1. Hose Diameter = 6.35mm [ 0.25" ] Outside Diamter

2. Hose Swivel Nut = 12.7mm [ 0.5" ] across the flats

3. If no hose or nut is available you can determine from the hose fitting. On a male fitting this will be approx 9.5mm [ 0.375" ]

4. Uses a 3/8th UNF thread connection. (Similar to 1/8th BSP in size but has a coarser thread)

5. Uses a male female cone connection within a female swivel nut as the pipe connection.

6. Hose connection uses a female cone, adapters must use male cone.

4AN Braided - Simply a larger style hose to that of the 3AN hose. Used in most US systems and WON systems where rules require it's use or on systems flowing more than 150Bhp.

1. Hose Diameter = 7.85mm [ 0.309" ] Outside Diamter

2. Hose Swivel Nut = 14.2mm [ 0.599" ] across the flats

3. If no hose or nut is available you can determine from the hose fitting. On a male fitting this will be approx 11.1mm [ 7/16" ]

4. Uses a 7/16th UNF thread connection.

5. Hose connection uses a female cone, adapters must use male cone.

6AN Braided - Simply a larger style hose to that of the 4AN hose. Used in systems that are flowing in excess of 450Bhp.

1. Hose Diameter = 10.8mm [ 0.425" ] Outside Diameter

2. Hose Swivel Nut = 17.35 [ 0.683 ] mm across the flats

3. If no hose or nut is available you can determine from the hose fitting. On a male fitting this will be approx 14.28 mm [ 9/16" ]

4. Uses a 9/16th UNF thread connection.

5. Hose connection uses a female cone, adapters must use male cone.