Diesel Line Threaded Connection Sealing

[Deleted member 36384]

I have a Vetus twin diesel filter housing with inlet and outlet manifold. There is water and diesel in the engine sump tray. Investigation has revealed that the water is from a swollen hose that has softened due to diesel and that that the source of the diesel is from the filter manifold threads, all of them.

The fitters used PTFE Tape (white colour) about 3 years ago when they installed the new system. I can pull some tape out the fittings and it feels quite normal, not slimy as if its reacting. The diesel hoses are braided and relatively heavy and are not supported being just laid along the sole between the engine bearer and a stringer, hence there is a bit of mass vibrating around the end fittings.

I will be dismantling the filter housing, resealing the various threads and supporting the hose. Before I start this I have some of questions which I hope the forum can help with.

1. Does PTFE tape set up to form a profile over time such that vibration could form a leak path through gaps?
2. PTFE Tape has been banned in most applications by my Employer because it is not reliable and has been the root cause of deaths (incorrect application). What is correct way for applying PTFE tape to threads say (tapered).
3. Permatex thread sealant appears to be a popular choice for liquid sealant but I cant find a UK supplier. Any ideas where to buy?
4. Would these Hylomar products, Universal Blue and 5059 (Previously 760) be suitable where there is an element of vibration.

Basically I am looking for good tips on successful, long term, diesel line thread sealing.

Thanks in advance,

BlowingOldBoots

 

[pvb]

I don't like to use PTFE tape on diesel fittings. If some sort of sealant is needed, I use a gasket compound such as Hermatite.

 

[Malish]

I would hope that your supporting of the hoses will remove the problem. I used one of the anaerobic sealants from hylomar some years ago to great effect on a fuel system installation (didn't want to use PTFE tape), worked a treat, never leaked.

 

[Martin_J]

I have for the past few years been using 'Jet Lube V-2 plus'!!! I know I have never seen it mentioned on the forums at all - hopefully someone else can confirm its usefulness.

http://www.jetlube.com/jetlube/productdetails.aspx?productId=728

If you read the pdf on that page it is non-setting, is designed for threaded connections and can be pressurized immediately. Main points that attracted me to it were - Can be used on potable water systems, working pressure 10,000 for liquids, can be used up to 2,000psi for gases, can be used on metals or plastics and is non-flammable. Recommended for pipes containing diesel (up to 145psi), natural gas, kerosene, water, Butane/Propane (up to 250psi) and even ammonia!

Is there anything against this product? - It's even non-toxic and environmentally safe...

Ooh - just read non-staining, low-odour and I am sure I bought it in B&Q!

 

[RobinBirch]

I've used hylomar universal blue for 'weepy' diesel probs -worked each time

 

[SHUG]

I've used hylomar universal blue for 'weepy' diesel probs -worked each time

Agree....excellent stuff.

 

[Deleted member 36384]

Thanks for the replies and suggestions. For such a simple task its easy to assume that sealing with tape or thread sealant requires no thought, however the taper thread is basic technology and does not lend its self to seal easy.

For me it gets slightly worse. Further inspection of the hose (mentioned in my original post) at the raw water filter identified that the bloody thread of the filter to ball valve or ball valve to skin fitting is now leaking as well. So perhaps the diesel leak has broken down the sealant around the raw water inlet threaded components.

At least I can sort it all before spring.

Thanks,

BlowingOldBoots

 

[Heckler]

I don't like to use PTFE tape on diesel fittings. If some sort of sealant is needed, I use a gasket compound such as Hermatite.

Stag!!
Funnily enough I took a threaded pipe connection out of a filter header the other day, looked at the threads and thought, HMM! someone used Stag on this!
Wonder where I would buy that nowadays? Hermetite we used on ordinary engines, Stag was for the big boys in industry! Same colour red and smelled the same.
Stu