Connecting 5mm fuel hose (2mm id) to a CAV filter head

webcraft

webcraft

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I am about to plumb in a diesel heater and want to connect the 5mm fuel hose (2mm id) to a CAV filter head. I would prefer to use flexible hose, not copper compression fittings.

I know lots of you will be horrified, will tell me I should use copper pipe, put a standpipe in the main tank etc, but I have my reasons.

So I really just need to know what fitting or fittings I will need and where to get them. I believe the CAV head outlet is normally 1/2" UNF .

Thanks in advance to anyone who can make a useful suggestion,

- W
 
webcraft said:
I am about to plumb in a diesel heater and want to connect the 5mm fuel hose (2mm id) to a CAV filter head. I would prefer to use flexible hose, not copper compression fittings.

I know lots of you will be horrified, will tell me I should use copper pipe, put a standpipe in the main tank etc, but I have my reasons.

So I really just need to know what fitting or fittings I will need and where to get them. I believe the CAV head outlet is normally 1/2" UNF .

Thanks in advance to anyone who can make a useful suggestion,

- W
Click to expand...

Is it really 2mm ID? That sounds very small for a fuel pipe.
 
I used BES for the components I needed to do a gas installation, they were very easy people to deal with and offered me good advice. ASAP supplies are owned by Euro Car Parts Ltd so a) you are dealing with a respected and reliable company and it's possible you may even
be able to collect from one of the local car parts stores? I know you have said you don't want to use copper but it really isn't that difficult to bend/fit and it might be easier to fit the CAV filter plus suitable compression fittings etc are easily available.
 
webcraft said:
I am about to plumb in a diesel heater and want to connect the 5mm fuel hose (2mm id) to a CAV filter head. I would prefer to use flexible hose, not copper compression fittings.

I know lots of you will be horrified, will tell me I should use copper pipe, put a standpipe in the main tank etc, but I have my reasons.

So I really just need to know what fitting or fittings I will need and where to get them. I believe the CAV head outlet is normally 1/2" UNF .

Thanks in advance to anyone who can make a useful suggestion,

- W
Click to expand...
Your surveyor might not like a non approved hose. However you can get a hose adaptor from various sources and then sweat (solder) a smaller size copper pipe into it to fit in the hose bore and long enough to give a secure fit.
 
I would suggest using normal fittings to go from the CAV to a small plastic inline filter, these often have both 8mm and 6mm compatibility.
Not only does it trap any dirt which gets through the CAV, it will also trap any air, which can cause issues with the heater.
At least you can see the air and that any bubble isn't growing.
Then you just need a bit of persuasion to fit a short bit of 5mm ID hose onto the filter, and put the 5mm OD hose into that. A proper bolt-up fuel clip should seal that OK, if it's stiff plastic pipe?
Or use put the small hose on the pump inlet and push 6mm hose on top?
My fuel pump seems to seal fine with 5mm ID hose on its inlet side, and a proper clip.
You could add a 1/4 turn valve, it can help with bleeding. And it's something to turn off if the heater goes ape.
I used a syringe to draw fuel as far as the filter, shorted the priming /bleeding malarkey.

You are not supposed to use copper with diesel.

By the way, the clear hose which comes with many heater kits has a bad reputation in some quarters so I am using some industrial plastic tube from pump to heater, with a short length of fuel hose to connect at the heater end.
 
Wing Mark said:
I would suggest using normal fittings to go from the CAV to a small plastic inline filter, these often have both 8mm and 6mm compatibility.
Not only does it trap any dirt which gets through the CAV, it will also trap any air, which can cause issues with the heater.
At least you can see the air and that any bubble isn't growing.
Then you just need a bit of persuasion to fit a short bit of 5mm ID hose onto the filter, and put the 5mm OD hose into that. A proper bolt-up fuel clip should seal that OK, if it's stiff plastic pipe?
Or use put the small hose on the pump inlet and push 6mm hose on top?
My fuel pump seems to seal fine with 5mm ID hose on its inlet side, and a proper clip.
You could add a 1/4 turn valve, it can help with bleeding. And it's something to turn off if the heater goes ape.
I used a syringe to draw fuel as far as the filter, shorted the priming /bleeding malarkey.

You are not supposed to use copper with diesel.

By the way, the clear hose which comes with many heater kits has a bad reputation in some quarters so I am using some industrial plastic tube from pump to heater, with a short length of fuel hose to connect at the heater end.
Click to expand...

Thanks, informative and useful...

- W
 
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