Ball Valve For Fuel?

[Tim Good]

Is there a specific material of a ball valve best for diesel? I assume that anything would do but what is the best? I only have to replace a few 1/4" valves so cost is not an issue I just want to ensure I get the best I can.

Secondly; is PTFE tape a no no for fuel valves? If so what is the best thing to use to make a decent seal?

 

[vyv_cox]

I suggest you look at ASAP's site under 'fuel valve'. Huge choice, not sure there is a 'best'.

Diesel injector pumps and injectors rely on very small clearances to function correctly. These can easily be blocked by strings of PTFE tape, or many other solids. The best seal is a copper olive, no sealant should be necessary if done properly. There have been several threads recently on the subject about gas (with you the OP?), the same applies to fuel.

 

[Tim Good]

I suggest you look at ASAP's site under 'fuel valve'. Huge choice, not sure there is a 'best'.

Diesel injector pumps and injectors rely on very small clearances to function correctly. These can easily be blocked by strings of PTFE tape, or many other solids. The best seal is a copper olive, no sealant should be necessary if done properly. There have been several threads recently on the subject about gas (with you the OP?), the same applies to fuel.

I don't recall asking about gas recently but thanks for the advice as always Vyv.

 

[Lon nan Gruagach]

Stainless steel would be my choice, but look at BES., about 1/3 the price of ASAP http://www.bes.co.uk/products/100.asp

note single part valves are reduced bore, 2 part are full bore and 3 part are maintainable

 

[Tim Good]

Looking at BES and some others the Stainless ones have a PTFE seal. If that breaks down in Diesel then surely that's a no no? The super cheap ASAP ones say "Teflon Seal and O Ring".

Should I be avoiding the lovely stainless jobbies with the PTFE seal?

http://www.asap-supplies.com/marine/brass-ball-valves/brass-ball-valve-female-each-end-405001

 

[sailorman]

mine is a brass gas cock

 

[prv]

I've always just used bog standard brass ones from ASAP. Certainly shouldn't be any risk of corrosion in diesel, and I can't forsee any other problems.

Pete

 

[Tim Good]

I think I'm going to opt for these which I recently bought for my water inlet manifold. They have a sliding latch which allows you to padlock the valve shut. A bit OTT but something extra to do when leaving the boat in an unfamiliar marina or anchorage.

http://www.valves-online.co.uk/acat...-Bore-Stainless-steel-Ball-Valve-2001_02.html

 

[vyv_cox]

PTFE is almost totally inert, and is not attacked by diesel fuel, or any other kind that I know of. It's the tape that's the problem, small fibres of it will inevitably break off when making joints up and some may well find their way downstream. I have some dramatic photos of a gas turbine that burnt and destroyed itself when a piece of PTFE tape became trapped across one of the combustor nozzles, diverting the flame path.

 

[prv]

They have a sliding latch which allows you to padlock the valve shut.

Never seen one of those before. An interesting idea, but it only needs a couple of spanners to take the handle off and turn the spindle directly

Pete

 

[Tim Good]

Never seen one of those before. An interesting idea, but it only needs a couple of spanners to take the handle off and turn the spindle directly

Ye of little faith:

 

[prv]

Ye of little faith:

Heh. I was thinking epoxy, or a file to round off the flats, but that's a more elegant solution. Shame it didn't occur to the valve manufacturer to use them as-supplied.

Pete

 

[Tim Good]

Heh. I was thinking epoxy, or a file to round off the flats, but that's a more elegant solution. Shame it didn't occur to the valve manufacturer to use them as-supplied.

I actually work in the padlock industry and the lockoff holes are just for safety internally to prevent someone turning something on whilst someone is working in or near a machine. In this case we need protection from thieves but who'd go for unlocking the nuts as you suggested. Conveniently I have access to these little beauties which I get sent in specifically for yachties in a special small version.

http://www.nothingbutpadlocks.com/advice/boat-locker/

I'll take some photos of valves and locks installed when I'm done.

 

[Tranona]

That type of lockable valve is popular in the US because it allows you to disable your seatoilet when going into the inland waterways.

 

[Kelpie]

PTFE is almost totally inert, and is not attacked by diesel fuel, or any other kind that I know of. It's the tape that's the problem, small fibres of it will inevitably break off when making joints up and some may well find their way downstream. I have some dramatic photos of a gas turbine that burnt and destroyed itself when a piece of PTFE tape became trapped across one of the combustor nozzles, diverting the flame path.

A fuel cock will usually be before the engine's fine filter, is there much realistic chance of strands of PTFE getting past that?

 

[lw395]

You have more need of something to stop the fuel being accidentally turned off.
I've heard more than one tale where a lever ball valve has got knocked into the off position by people rummaging in the locker or whatever, resulting in the engine stopping at an embarrassing moment.

 

[Tim Good]

You have more need of something to stop the fuel being accidentally turned off.
I've heard more than one tale where a lever ball valve has got knocked into the off position by people rummaging in the locker or whatever, resulting in the engine stopping at an embarrassing moment.

Well that's a good point actually that I didn't consider. I have done that myself but realised in time. Those ones from Valves Online would serve that purpose also.

 

[prv]

Well that's a good point actually that I didn't consider. I have done that myself but realised in time. Those ones from Valves Online would serve that purpose also.

I tend to use the T-handled ball valves for the same reason - less likely to get turned accidentally.

Pete

 

[nigelmercier]

I tend to use the T-handled ball valves for the same reason - less likely to get turned accidentally.

Exactly what I have, haven't fitted it yet of course.

 

[haydude]

Marine ball valves for water are good also for fuel. Do not use PTFE because diesel melts it. I used sikaflex successfully. Sikaflex is not affected by diesel or solvents once cured.