Plastic fuel tanks

[Hadenough]

I've decided to bite the bullet (I think) and replace my two 40 year old steel deisel tanks. Big job in that it is engine out but relatively easy once I have done that and I can tidy up a lot of other things at the same time.
The tanks are mid ships in the engine bay above and to port and stbd of the engine. My proposal is to replace them with two standard plastic tec tanks and my questions are; Is it ok to use plastic deisel tanks in an engine bay? What will the insurers think? Has anyone gone the same route?

 

[Caer Urfa]

I've decided to bite the bullet (I think) and replace my two 40 year old steel deisel tanks. Big job in that it is engine out but relatively easy once I have done that and I can tidy up a lot of other things at the same time.
The tanks are mid ships in the engine bay above and to port and stbd of the engine. My proposal is to replace them with two standard plastic tec tanks and my questions are; Is it ok to use plastic deisel tanks in an engine bay? What will the insurers think? Has anyone gone the same route?

I fitted twin 57 litre (each) plastic diesel tanks 12 years ago to port/stb of the engine as this is very common on a lot of boats, I have never had or heard of problems with insurance companies or from surveys.

However I would say the nearest side of the tanks in relation to the engine is about 300mm min and the tanks as can be seen are mounted slightly above the level of the engine.

Of interest I designed each tank to have it's own filter system, and I can run the engine from both tanks, or the port or stb tank only, and I can send the fuel return also to both tanks or again seperate to port or stb and the tanks are also securly strapped in.

This set up lets me 'switch tanks' in seconds and allows me to change filters if neccassary 'at sea' with the engine running.

Also as you can see we have primary and secondary filters fitted and are gravity fed!.

Hope this might help.

Mike

 

[Cloven]

All UK Hunters come with plastic tanks as standard. My last 2 boats have had them and no problems at all.

If you are getting one made, consider having an access hole in the top large enough to get your hand in. Makes cleaning out the tank a doddle in the event of fuel contamination.

 

[Ex-SolentBoy]

Rustler Yachts are fitted with Tektanks as standard. I really like them. I would specify them with inspection ports and fittings for Offshore Sytems NMEA 2000 gauges.

 

[Hadenough]

Caer
Now you've really upset me! After seeing the pics of your engine bay I realise the the bullet has to be bitten!!! Our engine bay is almost identical so the pics are really usefull. Any chance of a schematic of your valveing / filter arrangement?

Dave and Ex Sol

Thanks too, reassuring to know that plastic is a standard

 

[Caer Urfa]

Caer
Now you've really upset me! After seeing the pics of your engine bay I realise the the bullet has to be bitten!!! Our engine bay is almost identical so the pics are really usefull. Any chance of a schematic of your valveing / filter arrangement?

Dave and Ex Sol

Thanks too, reassuring to know that plastic is a standard

Hi Dave

PM me your e-mail address if your stuck and I will try and do something for you. but here we go.

I kept things simple, each tank first has a shut off in the gravity fuel pipe from it to the Delphi Type HDF 296 primary filter.

From each Primary filter the pipe runs to a central three way control valve.

From this control valve piping goes to the lift pump, but in the middle of the pipe is a main fuel 'main shut off' valve.The reason for the 'main' shut off fuel valve is for bleeding the primary filters, I can disconnect here if necassary and fit a 'priming bulb', much quicker and little mess.

The return fuel pipe goes to a secondary Crossland 370 filter, this pipe also includes an 'in line' none return valve.

From the secondary filter fuel goes via a 'Tee' fitting to either the port or starboard fuel shut off valve (as per last photo), from each valve fuel goes direct back into selected tank.

All delivery fuel is by certified 3/8" dia fuel pipe, Return fuel is via 1/4" dia fuel pipe.

Tips:
The primary filters want to be 'below' the bottom level of the fuel tanks.
Use as short a pipe run as possible, (less effort for the lift pump).

Make sure any pipeing can not rub on something when the engine is running.
All parts available from ASAP Supplies http://www.asap-supplies.com/marine/fuel-systems

Hope this helps and a few more pics, Note, in the third picture the operating lever on the three way valve is removed for safety, see picture of the valve without the hose tails fitted etc..

Hope this helps

Mike

 

[Pete7]

Has anyone gone the same route?

This is entertaining and on topic, looks like exactly what you are considering.

Tec Tanks- YouTube



Pete

 

[VicS]

A commentary instead of the irritating musical accompaniment would have made an entrtaining video into an informative one!

 

[Hadenough]

Hi Dave

PM me your e-mail address if your stuck and I will try and do something for you. but here we go.

I kept things simple, each tank first has a shut off in the gravity fuel pipe from it to the Delphi Type HDF 296 primary filter.

From each Primary filter the pipe runs to a central three way control valve.

From this control valve piping goes to the lift pump, but in the middle of the pipe is a main fuel 'main shut off' valve.The reason for the 'main' shut off fuel valve is for bleeding the primary filters, I can disconnect here if necassary and fit a 'priming bulb', much quicker and little mess.

The return fuel pipe goes to a secondary Crossland 370 filter, this pipe also includes an 'in line' none return valve.

From the secondary filter fuel goes via a 'Tee' fitting to either the port or starboard fuel shut off valve (as per last photo), from each valve fuel goes direct back into selected tank.

All delivery fuel is by certified 3/8" dia fuel pipe, Return fuel is via 1/4" dia fuel pipe.

Tips:
The primary filters want to be 'below' the bottom level of the fuel tanks.
Use as short a pipe run as possible, (less effort for the lift pump).

Make sure any pipeing can not rub on something when the engine is running.
All parts available from ASAP Supplies http://www.asap-supplies.com/marine/fuel-systems

Hope this helps and a few more pics, Note, in the third picture the operating lever on the three way valve is removed for safety, see picture of the valve without the hose tails fitted etc..

Hope this helps

Mike


Apologies for the late response, work gets in the way sometimes!

Many thanks for the detailed answer and photos I can figure out the layout from those. Couple of Q's though. I take it that the system is that if you are drawing from the port tank you set the valves so it is returning to the port tank (and vice versa). If you set the three way valve to both does it balance the two tanks through the filters? Finally, have I got it right that you have a filter on the return?

 

[onesea]

I've decided to bite the bullet (I think) and replace my two 40 year old steel deisel tanks.....

Why? Is engine already out? Have you had that many problems with crud in fuel?

 

[Hadenough]

Why? Is engine already out? Have you had that many problems with crud in fuel?

No but it could do with coming out to give access to my 40 year old electrics for an upgrade and to clean out my disgusting bilges. And yes over the last few years I have had two blockages in the shut off valves which feed from the bottom of the tanks, filter had a trace of bug at the last change too. The existing tanks are showing signs of rust on the outside so I am nervous about the internal condition.