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Thread sealer for threaded fuel supplya


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Hi All.

As the title says, I'm in the process of fitting a fuel pressure gauge in the Cab and need to screw in the adaptor just before the Metering unit.

What should I use on the thread, will PTFE be any good ?

TA Mark

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Mark,

I would not fit a fuel pressure gauge in the cockpit.

Oil pressure gauges have been known to fail - it makes a mess.

Pressurised fuel spraying into the cockpit......doesn't bear thinking about.

An electronic sensor and gauge is what you need.

Peter

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Hi Peter.

That's what I've got.

Mark

Mark,

My apologies.

One of the Loctites I think:

http://www.loctite.co.uk/thread-sealing-9170.htm

Teflon tape might release threads into MU.

Peter

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Also (sorry, premature posting syndrome).

When looking for advice on fuel hose/sealing/joints/fittings etc, I found a farm machinery shop very helpful!

Find one that services combines/JCBs etc (BIG kit, not lawnmowers), as they have good stocks/advice on suitable products/solutions.

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Here is the Hylomar website on the Blue and the Red: http://hylomar.com/hylomar-product-range/gasket-jointing-compounds/

 

Blue would seem to be the bunny, but I'd be concerned that more than the very mearest smear would exude beads that got into the fuel flow.

Like brake joints, that don't need a sealant, fuel joints should be designed to seal without.

 

I have a pressure sensor under the bonnet, and the joints to that are assembled dry, as are all the joints in my fuel system.

John

Edited by john.r.davies
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Hello, the problem with PTFE tape is there are different types, white is for water and I think it dissolves in petrol, try this, Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant Liquid Gasket Maker 4oz., it is used in the marine world and is well thought of, cheers, Andrew

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Hi John.

How do you seal the threads ?

Mark.

 

You don't, Mark, any more than you seal the threads in a brake connection.

The end to the line and the face of the brake component, eg slave cylinder, are shaped to squeeze together and seal.

The engineering term is a "compression seal" and the line may be shaped or an 'olive' used to promote the seal.

 

As I say, my entire fuel system is connected by dry joints, and don't leak a bit!

 

My oil cooler has hoses with connectors swaged on, made by a local hydraulics firm. Hydraulics operate at pressures that would explode any cars fuel, oil or any other system, and they are connected dry.

 

John

Edited by john.r.davies
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Permatex 59214 or Loctite 542 are fuel safe hydraulic thread sealants.

PTFE tape is petrol resistant but not had much luvk using it to seal fine threads at the pressures in the Lucas PI system.

 

Blue Hylomar isn't intended for continuous contact with fuel.

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A correctly installed tapered fitting with PTFE paste or the Permatex mentioned above should be good for 5,000 PSIG. I have used many tapered fittings in the Oil & gas industry without problem.

 

A PI system is relatively low pressure.

 

Cheers

Graeme

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