Fuel vent/selection/filter questions

[Target9000]

Forgive me if the answers have been given before; I did attempt to search.

I'm in the process of installing two new fuel tanks in our w32. Previously there was only a starboard tank, but now we'll have a port tank as well. This complicates things slightly and since it is fuel, I wanted to ask the "experts".

1. What do I need for filtration? We'll have a Beta Marine 38. Is a single Racor 500 good enough? Our cruising plans are world wide, so fuel will be variable in quality I'm assuming. Should I spring for the "dual racor" now? One reason I ask is because in my searching I saw some other people trying to switch from single to dual filter setups, yet I never saw "why" they wanted to do that. I'd prefer a single filter, but I don't want to be penny wise and pound poor. Let me hear your wisdom on this.

2. Since there was a single vent installed for the original tank, I'd like to use it for both tanks instead of putting another hole in the hull. Is it alright to "T" the vent line? The vent is above the fill level on both tanks.

3. What do you use for the fuel selector? Do they make an appropriate valve for switching tanks that includes return lines? I've seen one on the Parker website but it was a solenoid. I'd prefer manual only. Is it best just to use two valves for this?

4. Should the order be this. Tanks -> Selector valve -> Racor -> Engine ? Or am I wrong in thinking I can get away with a single racor and I need one for each tank?

5. The tanks I had made up are aluminum and have a bonding bracket at the top near the fuel fill. The person I ordered from said that since it was diesel I could ignore the bonding. The person at the boat yard seemed adamant it be bonded. I thought the bracket must be there for gasoline tanks. Is it okay to leave that bracket alone and not bond it to the fuel fill?

Feed back appreciated. Also where is the best place to buy the filters and hoses/barbs I'll need? I hear you can't just pick up the connectors the filter system at the local hardware store.

[delmarrey]

A pre-filter (30 microns) and a main filter (3-5 microns) w/water separators/bowls is usually best. Both tanks can be run thru the same filter system by use of a switching valve. Which brand, the choice is yours but get one that parts are available locally and is rated for your size of motor or larger. Do carry extra filter elements.

Vents;

46 C.F.R. 182.*** Subpart D—Specific Machinery Requirements
Subpart D—Specific Machinery Requirements
§ 182.400 Applicability.
(a) This subpart applies to all propulsion and auxiliary machinery installations of the internal combustion piston type.
(b) Requirements of this subpart that are only applicable to engines that use gasoline or other fuels having a flashpoint of 43.3° C (110° F) or
lower are specifically designated in each section.
(c) Requirements of this subpart that are only applicable to engines that use diesel fuel or other fuels having a flashpoint of more than 43.3° C
(110° F) are specifically designated in each section.
(d) Where no specific gasoline, diesel, or other fuel designation exists, the requirements of this subpart are applicable to all types of fuels and
machinery.

§ 182.450 Vent pipes for fuel tanks.
(a) Each unpressurized fuel tank must be fitted with a vent pipe connected to the
highest point of the tank.
(b) The net cross sectional area of the vent pipe for a gasoline fuel tank must not
be less than that of 19 millimeters (0.75 inches) outer diameter (O.D.) tubing
(0.9 millimeter (0.035 Inch) wall thickness, 20 gauge), except that, where the
tank is filled under pressure, the net cross sectional area of the vent pipe must be
not less than that of the fill pipe.
(c) The minimum net cross sectional area of the vent pipe for diesel fuel tanks
must be as follows:
(1) Not less than the cross sectional area of 16 millimeters (0.625 inches) outer
diameter (O.D.) tubing (0.9 millimeter (0.035-inch) wall thickness, 20 gauge), if
the fill pipe terminates at the top of the tank;
(2) Not less than the cross sectional area of 19 millimeters (0.75 inches) O.D.
tubing (0.9 millimeter (0.035-inch) wall thickness, 20 gauge), if the fill pipe
extends into the tank; and
(3) Not less than the cross sectional area of the fill pipe if the tank is filled under
pressure.
(d) The discharge ends of fuel tank vent pipes must terminate on the hull exterior
as high above the waterline as practicable and remote from any hull openings, or
they must terminate in U-bends as high above the weather deck as practicable
and as far as practicable from openings into any enclosed spaces. Vent pipes
terminating on the hull exterior must be installed or equipped to prevent the
accidental contamination of the fuel by water under normal operating conditions.
diameter (O.D.) tubing (0.9 millimeter (0.035-inch) wall thickness, 20 gauge), if
the fill pipe terminates at the top of the tank;
(2) Not less than the cross sectional area of 19 millimeters (0.75 inches) O.D.
tubing (0.9 millimeter (0.035-inch) wall thickness, 20 gauge), if the fill pipe
extends into the tank; and
(3) Not less than the cross sectional area of the fill pipe if the tank is filled under
pressure.
(d) The discharge ends of fuel tank vent pipes must terminate on the hull exterior
as high above the waterline as practicable and remote from any hull openings, or
they must terminate in U-bends as high above the weather deck as practicable
and as far as practicable from openings into any enclosed spaces. Vent pipes
terminating on the hull exterior must be installed or equipped to prevent the
accidental contamination of the fuel by water under normal operating conditions.
(e) The discharge ends of fuel tank vent pipes must be fitted with removable
flame screens or flame arresters. The flame screens must consist of a single
screen of corrosion resistant wire of at least 30×30 mesh. The flame screens or
flame arresters must be of such size and design as to prevent reduction in the net
cross sectional area of the vent pipe and permit cleaning or renewal of the flame
screens or arrester elements.
(f) A vessel of not more than 19.8 meters (65 feet) in length carrying not more
than 12 passengers, with fuel gasoline tank vents built in accordance with ABYC
Project H–24, or 33 CFR 183, subpart J, or with diesel fuel tank vents built in
accordance with ABYC Project H–33, will be considered as meeting the
requirements of this section.
(g) Where a flexible vent pipe section is necessary, suitable flexible tubing or hose
having high resistance to salt water, petroleum oils, heat and vibration, may be
used. Such hose must overlap metallic pipe ends at least 11/2 times the pipe
diameter and must be secured at each end by clamps. The flexible section must
be accessible and as near the upper end of the vent pipe as practicable.
(h) Fuel tank vent pipes shall be installed to gradient upward to prevent fuel from
being trapped in the line.
§ 182.455 Fuel piping.
(a) Materials and workmanship. The materials and construction of fuel lines,
including pipe, tube, and hose, must comply with the requirements of this
paragraph.
(1) Fuel lines must be annealed tubing of copper, nickel-copper, or copper-nickel
having a minimum wall thickness of 0.9 millimeters (0.035 inch) except that:
(i) Diesel fuel piping of other materials, such as seamless steel pipe or tubing,
which provide equivalent safety may be used;
(ii) Diesel fuel piping of aluminum is acceptable on aluminum hull vessels
provided it is a minimum of Schedule 80 wall thickness; and
(iii) when used, flexible hose must meet the requirements of §182.720(e) of this
part.
(2) Tubing connections and fittings must be of nonferrous drawn or forged metal
of the flared type except that flareless fittings of the non-bite type may be used
when the tubing system is of nickel-copper or copper-nickel. When making tube
connections, the tubing must be cut square and flared by suitable tools. Tube
ends must be annealed before flaring.
(3) Cocks are prohibited except for the solid bottom type with tapered plugs and
union bonnets.
(4) Valves for gasoline fuel must be of a suitable nonferrous type.
(b) Installation. The installation of fuel lines, including pipe, tube, and hose, must
comply with the requirements of this paragraph.
(1) Gasoline fuel lines must be connected at the top of the fuel tank and run at or
above the level of the tank top to a point as close to the engine connection as
practicable, except that lines below the level of the tank top are permitted if
equipped with anti-siphon protection.
(2)Diesel fuel lines may be connected to the fuel tank at or near the bottom of
the tank.
(3) Fuel lines must be accessible, protected from mechanical injury, and
effectively secured against excessive movement and vibration by the use of soft
nonferrous metal straps which have no sharp edges and are insulated to protect
against corrosion. Where passing through bulkheads, fuel lines must be protected
by close fitting ferrules or stuffing boxes. All fuel lines and fittings must be
accessible for inspection.
(4) Shutoff valves, installed so as to close against the fuel flow, must be fitted in
(1) Gasoline fuel lines must be connected at the top of the fuel tank and run at or
above the level of the tank top to a point as close to the engine connection as
practicable, except that lines below the level of the tank top are permitted if
equipped with anti-siphon protection.
(2) Diesel fuel lines may be connected to the fuel tank at or near the bottom of
the tank.
(3) Fuel lines must be accessible, protected from mechanical injury, and
effectively secured against excessive movement and vibration by the use of soft
nonferrous metal straps which have no sharp edges and are insulated to protect
against corrosion. Where passing through bulkheads, fuel lines must be protected
by close fitting ferrules or stuffing boxes. All fuel lines and fittings must be
accessible for inspection.
(4) Shutoff valves, installed so as to close against the fuel flow, must be fitted in
the fuel supply lines, one at the tank connection and one at the engine end of the
fuel line to stop fuel flow when servicing accessories. The shutoff valve at the tank
must be manually operable from outside the compartment in which the valve is
located, preferably from an accessible position on the weather deck. If the handle
to the shutoff valve at the tank is located inside the machinery space, it must be
located so that the operator does not have to reach more than 300 millimeters
(12 inches) into the machinery space and the valve handle must be shielded from
flames by the same material the hull is constructed of, or some noncombustible
material. Electric solenoid valves must not be used, unless used in addition to the
manual valve.
(5) A loop of copper tubing or a short length of flexible hose must be installed in
the fuel supply line at or near the engines. The flexible hose must meet the
requirements of §182.720(e).
(6) A suitable metal marine type strainer, meeting the requirements of the
engine manufacturer, must be fitted in the fuel supply line in the engine
compartment. Strainers must be leak free. Strainers must be the type of opening
on top for cleaning screens. A drip pan fitted with flame screen must be installed
under gasoline strainers. Fuel filter and strainer bowls must be highly resistant to
shattering due to mechanical impact and resistant to failure due to thermal
shock. Fuel filters fitted with bowls of other than steel construction must be
approved by the Commandant and be protected from mechanical damage.
Approval of bowls of other than steel construction will specify if a flame shield is
required.
(7) All accessories installed in the fuel line must be independently supported.
(8) Outlets in gasoline fuel lines that would permit drawing fuel below deck, for
any purpose, are prohibited.
(9) Valves for removing water or impurities from diesel fuel in water traps or
stainers are permitted. These valves must be provided with caps or plugs to
prevent fuel leakage.
(c) Alternative procedures. A vessel of not more than 19.8 meters (65 feet)
carrying no more than 12 passengers, with machinery powered by gasoline and a
fuel system built in accordance with ABYC Project H–24, or 33 CFR 183, subpart
J, or with machinery powered by diesel fuel and a fuel system built in accordance
with ABYC Project H–33, will be considered as meeting the requirements of this
section.
[CGD 85–080, 61 FR 986, Jan. 10, 1996, as amended by USCG–2001–10224, 66
FR 48621, Sept. 21, 2001; USCG–2004–18884, 69 FR 58351, Sept. 30, 2004]

[James S]

They do make double selector valves that handle the supply and return lines at the same time...I have one, but got it used from a boat repair shop, so don't know where you'd source it from.
My supply and return lines go from the tanks to each side of the selector valve. the supplies outlet from the valve goes to another valve that selects one or the other primary Racor filters.....outlet from the selected filter goes to the secondary filter that's on the engine.

I definitely recommend having two filters with the ability to select between them.

Thats about all I can help you with.

Had a look at your site...man that bilge was nasty...big job mucking it out....

[roverhi]

The advantage of a dual filter system is you can switch between them and still keep the engine running. If you should get bad fuel or accumulated gunk in the tank clogs a filter, you've got restricted to no engine power until you change the filter element and clean out the filter. With two filters, you can switch to the other filter and continue on until that filter clogs up. Hopefully that won't happen quickly and you'll have full power till it's convenient for you to change the filters. With the exception of a lot of water in the fuel, the filters shut fuel flow down progressively as they fill up with gunk. The amount of fuel that gets through is just reduced to the point where the engine output is reduced and, eventually, so little fuel gets through the engine won't run.

I'd have a selector valve for the tanks and then one for the filters, if you go with two. If you make the filters tank specific, they will only work with that tank. If one tank is empty and the other clogs the filter because of crud in the fuel, you're SOL until you change the filter.

In most instances, you can get by with just a single filter because filters don't just shut off the fuel instantly unless it's water causing the problem. I've only got one Racor 500 for my Yanmar 3GM and it's not been a problem till a TransPac and sitting in the tropics for a few months stirred up the gunk in the tank. Went out for a day sail and the engine suddenly lost power and would only run at about half power and getting progressively worse. Shut the engine down and sailed most of the way back to the slip and then motored into the slip at not much above idle. The filter was totally gummed up. Had to take the filter completely apart and scrub out the water separator bowl that was largely filled with a gelatinous goo. USE A BIOCIDE ADDITIVE IN YOUR FUEL. FWIW, the filter had less than a 100 hours of use before it clogged up.

Everyone seems to have their own ideas about micron size of the filter element. I don't know what size my Racor had but it allowed some of the goo to get to the engine primary filter. Definitely go with the smallest micron size for the engine filter. Clogged/corroded/worn injector pump and injectors are very expensive to repair. Racor sells a vacuum gauge to put on the the filter. The gauge will tell you when the filter begins to restrict fuel flow.

One tank vent is probably okay as long as the vent line from the new tank doesn't have any dips and flows back to the tank. If you get fuel in the vent line that can't gravity flow out, it will stop the vent from doing it's thing till there is enough negative pressure to suck the fuel out. Probably more a problem when filling the tank than in operation.

Diesel fuel is EXTREMELY hard to ignite accidentally. The bonding strap is probably not necessary as it's doubtful an electrical spark would ignite the fuel. It shouldn't be that big a thing to run a bonding wire to the tank just to be sure, however.

[Jim Cate]

G'Day Target,

In our boat there are 3 tanks and they all use a common vent line. No problems if the hoses are a reasonable size and the tee fittings appropriate.

Our set up has separate valves for supply and return lines. We've found this useful as a means of transferring fuel from one tank to another -- supply from one, return to another. Might not be of use to you, but we like it.

If you are going to have two primary filters I would certainly recommend setting them up with valves allowing you to switch between them. I set ours up that way with inexpensive 3-way valves... hell of a lot less expensive than the Racor setup.

Finally, try to locate the filters where a bit of spillage of diesel whilst changing the elements is easy to clean up. PErhaps you can do it without spilling, but I don't seem to be that clever!

Cheers

[Target9000]

Thanks for the feedback guys

[captain58sailin]

What I have is 3 tanks, 1 main engine, 1 generator. I already had the 2 racors on board, and they were plumbed in with a laybrinth of vavles & hoses which was almost impossible to decipher. I took the two racor units and mounted them to an aluminum plate and put a small aluminum manifold between them and installed (2) three way valves so that I could change the direction of the supply and return on the fly and isolate the dirty racor. I also purchased 2 other manifolds one for the supply and one for the return and equipped them with stainless ball valves so there is only one line going from the tank manifold to the supply side of the racor manifold, and one return line going to the return manifold from the 2 engines. I would also recommend putting a 12 volt dc pump on the supply side to make it easy to pressure up your system after you have changed your filter. You can also install a vaccuum gauge on the manifold between the racors so that you can monitor their condition and not wait until your engine starts to choke, before switching filters. There are a couple of manufacturers of the manifolds online, and they will either make them to order or usually they have something in stock that will do what you need with a minimum of adapting. I was able to get what I needed off of the shelf for about $50.00 each including shipping, I went with aluminum since it is a low pressure environment. I got my 3 way valves and stainless ball valves off of ebay for a fraction of what the chandler would have charged me. It helps to sit down and draw up a diagram of how everything is going to flow, before ordering stuff. I was able to put my system together for about $150.00 US including all the hardware and a similar unit at my chandlers runs about $2000.00 US, for your system I would think it would be much less. The last thing I want is fuel trouble when I am underway offshore.

[DeepFrz]

I'll only comment on the vent. Make sure the T is well above the level of the fuel when the boat is heeled. Otherwise you will have fuel flowing back and forth between the tanks when you tack and you will not be sure how much is in what tank. You don't want to run your tank dry, as you will then have to go through the process of bleeding the fuel system, probably in a seaway. And hopefully you will have some fuel left in the other tank.

[Target9000]

The vent line is well above the tank fill and should be there even when heeled, so we'll just T the line.

I went ahead and ordered one of the dual turbine setups. All of your reasoning on why you should have two made a lot of sense.

I ordered griffin filters were way more reasonably priced than the name brand Racors. I was shocked at how much more expensive the name brand stuff was. Hopefully I didn't sacrifice too much quality. But it seemed a good compromise to spend a little more and go with the dual setup.

We'll go with the dual 3way valves for supply and return selection. I appreciate the tip on using the return to balance the tanks out Jim.

Also, thanks for the tips Peter. I've always enjoyed your posts that have specific insight into the W32. We'll certainly use some sort of fuel system additive to protect the diesel.

James, It sure was a nasty bilge project. The whole boat is pretty nasty really. But its what we could afford and we love her just the same. The bilge is pretty clean now though. I can tell you before we got in there and degreased the whole thing it smelled like a sumo wrestler took a crap in an old tire then filled it with diesel and lit it on fire. Now it smells sort of like orange degreaser. Vast improvement!

[James S]

Don't forget to strap or otherwise fix those new tanks down.

[Target9000]

Originally Posted by James S

Don't forget to strap or otherwise fix those new tanks down.

Something else I've been agonizing over. The starboard tank has metal straps already that are through bolted to the hull. The port tank needs some fastening. I found that in the W32 they used 2 methods to hold the tanks in place. The straps look pretty good but once again I have to put holes in the hull.

The alternative method was to put a block of wood between the deck and the thank and screw it to the cockpit well wall to hold the tank down. Sounds sort of strange but a lot easier.

I'll probably just go with straps, but what a pain. :P

[chris07732]

You asked where to get filters/fittings/etc. McMaster Carr is great site, industrial, not necessarily marine. Very user friendly website, easy to order and arrange shipping. By the way, just spent an hour reading your Burning Man reports. I've always wanted to do the event, but like Woodstock, always found reasons not to. Reading about your experiences was the next best thing. Thanks. Good luck with the Sundowner

[Target9000]

Originally Posted by chris07732

You asked where to get filters/fittings/etc. McMaster Carr is great site, industrial, not necessarily marine. Very user friendly website, easy to order and arrange shipping. By the way, just spent an hour reading your Burning Man reports. I've always wanted to do the event, but like Woodstock, always found reasons not to. Reading about your experiences was the next best thing. Thanks. Good luck with the Sundowner

Glad you enjoyed them Chris. If you ever get a chance and are interested I'd recommend going. Interestingly enough I think we field more traffic on the website from google searches and links to the burning man journals than we do stuff about the boat. And thanks for the tip on sources.

[James S]

Originally Posted by Target9000

Something else I've been agonizing over. The starboard tank has metal straps already that are through bolted to the hull. The port tank needs some fastening. I found that in the W32 they used 2 methods to hold the tanks in place. The straps look pretty good but once again I have to put holes in the hull.

The alternative method was to put a block of wood between the deck and the thank and screw it to the cockpit well wall to hold the tank down. Sounds sort of strange but a lot easier.

I'll probably just go with straps, but what a pain. :P

As long as your sure the wall and that part of the tank are up to the task, I go with the block of wood.

[chris07732]

I just installed a pair of new tanks. In place of the impervious rubber or plastic "cushion" you place on the stringer the tank sits on, I imbedded the tanks in a thick layer of 5200. I put in small squares of the rubber cushion on the stringer before troweling on the 5200 so the tank wouldn't squeeze out the 5200. The tanks, 80 gal each, aren't going anywhere, and they won't slip around if my blocking or straps, if you use them, get loose. I vote for the blocking rather than straps also.