Sealant for fuel filter

[RJJ]

Hi all

About to install a new diesel primary filter (racor knock off) and wondering if / how I need to seal the threads where the wee brass hose tails screw into the filter housing?

I have loctite 55 or CT1 to hand. Any thoughts welcome.

Thanks as always.

 

[Daverw]

You need to use sealing washers, something like dowty washers

 

[RJJ]

So we are going to go with "tru blu" PTFE pipe thread sealant from Toolstation. £3.23 for 50g. Will let you know how it goes!

 

[Refueler]

Depends on the thread type .. if tapered - nothing ... if straight then washers ..

 

[Poignard]

I believe the threads are 1/4" NPT, ie tapered so, as Refulgent says, no sealant should be needed.

Search results for: '1/4"NPTM'

 

[Daverw]

I believe the threads are 1/4" NPT, ie tapered so, as Refulgent says, no sealant should be needed.

Search results for: '1/4"NPTM'

My Racal copy had metric parallel threads

 

[Poignard]

My Racal copy had metric parallel threads

'
That is interesting, and something to beware of.

Here's the Racor datasheet:

https://www.parker.com/static_content/parkerimages/Racor/10219 Rev A (120A and 120B Series).pdf

As you can see: 1/4" NPT

I'm wondering if the filter elements for your copy would fit the genuine Racor body. They might be a lot cheaper. The price of the Racor ones is getting a bit steep.

 

[Daverw]

Mine was a different filter housing FG500 with the drop in cartridge, Ive been told that the original Racor patent has expired hence the copies coming to the market.

 

[Freebee]

Loctite 577 is the stuff to use.

 

[Refueler]

If you never intend to unmount ... disconnect ... then a thread lock fluid maybe ... blue for non permanent ... red for permanent.

The main thing with any tapered joint - is never use PTFE tape ... that's straight from a master fitters mouth !! when he was re-doing a joint on a boat while I was chatting with him. He reckoned it was a common error ...

With fuel joints where face to face ... I was always told to get the correct fibre washers designed for the job ... copper washers where specified ... and try not to re-use especially the copper ones !!

 

[VicS]

So we are going to go with "tru blu" PTFE pipe thread sealant from Toolstation. £3.23 for 50g. Will let you know how it goes!

If the threads are parallel the fitting will be shouldered and tighten onto a sealing washer . Dowty type as suggested or perhaps just plain annealed copper washers

If the threads are tapered they normally require a sealant or ptfe tape to fill the voids between the threads

But if they are NPTF, as stated in the data sheet, they are dry sealing for fuel and should not need a sealant, especially not ptfe tape .

(Something like Loctite 577 should do no harm and being of medium strength can be undone with ordinary hand tools)

 

[rotrax]

It uses parallel threads tightening down onto a slight cone - a bit like an old AMAL motorbike carb fitting. I used locktite 577 on mine. Just to be certain no leak along the threads. The cone SHOULD do the sealing, but you never know on fuel systems!

I tend to use it on all hydraulic threads.

After all, it is what it was made for.