Piping material for Fuel Filtration Plumbing

[Charles Brown]

Introduction:

Tony’s Tips on multi-stage diesel fuel filtration brought me to the Seaboard Marine website.

Specifically, I was doing a DDG image search for how others plumb and support a multiple canister, multiple step down diesel fuel filtration system for the bulk transfer of fuel from a 100 gallon steel transfer tank to the onboard tank of the device using the fuel… be it a boat or a backhoe.

Tony’s beautifully arranged, symmetrically laid out, and sturdily supported fuel filter pictures attracted my eye, and immediately after reading these two articles: “Marine Fuel Filtration ‘The Seaboard Way’ “ and “Understanding Fuel Line Sizes vs. Fuel Supply Restriction” …I joined the forum to learn how to achieve the type of diesel fuel filtration quality explained in those two articles, even though I do not own a boat.

Question:

Hard pipes and fittings for a 3/4″ lines are available in a few different materials. I purchased two Fill-Rite filter heads from Tuthill, a manufacturer of diesel fuel transfer pumps, and the filter heads were made of iron, while the bright pipe nipple included with the kit appeared to be galvanized steel.

This surprised me, because I’ve often read that diesel isn’t compatible with galvanized piping, due to diesel leaching the zinc out of the material. Yet Fill-Rite is a leading brand in the field of diesel fuel transfer pumps, so one would think if there is an issue with diesel and galvanized, they would know about it.

Yet, often times cost is an issue, and companies wanting to stay in business end up producing what the market will buy, and the market, like fluid, flows to the lowest price point. Most people want the cheapest price possible. For me, the cost to do the work over again is greater than the cost to do it right once.

So I looked at brass fittings, even before I stumbled across Tony’s images which show copious use of 90° brass elbows and 45°’s, in both as cast as well as machined formations. My search for compatibility between diesel and brass led to a number of forks in the road.

There are several types of brass… yellow, gold, red, bronze… and each differs from each other based on the percentage of copper content and zinc content. Some suggest that diesel fuel is not compatible with copper, not compatible with zinc, and that brass “has a corrosive reaction” with Ultra Low Sulfur Diesel, which is the only diesel available locally…. besides B20 biodiesel, which likely has it’s own piping material compatibility concerns.

In addition to chemical reactions between diesel and the piping material, there is also the issue of mechanical integrity of the threaded connections in a mobile application over rough roads, and the cantilevering weight acting on the threads as they are asked to hold a series of large heavy filters, each filled with diesel.

Which metal piping material is rugged enough to remain stable, and not fail from fatigue? Is that the reason why Fill-Rite included a galvanized steel pipe nipple, and shows pictures of galvanized steel elbows in all their literature (where the filters have no other support but the pipe threads).

Non galvanized black iron pipe would corrode… and having corrosion particles introduced in between stages of filters via the piping that joins them would undermine the effort.

That seems to leave only stainless steel piping and fittings, which I rarely see used in the field.

So I’d like to know what the best practices might be for selecting pipe and fitting material in creating a multi-stage filter manifold plumbed with 3/4″ diameter throughout, from 12vdc tank mounted bulk transfer pump outlet, through a series of elbows and filter heads, to the point where the fuel filling hose gets attached.

Topic

[Tony Athens]

Charles,

That’s quite the post, but I’m kinda lost here,………..1st thing is—–I am curious about what engine might you be using that would require 3/4″ ID fuel plumbing “throughout” ?

Also, why are you buying componets to design your sysem that are obviously made to on-shore commercial fuel dispensing facilities? Nothing wrong with that, but please explain
the reasoning here…… Believe me, I can learn too..

And last for now, with such an extensive & involed post, please post the diagram of the entire system–I’m especially interested in your fuel priming system and the realitive height of all the pices to each other as to elevtaions of all of the components in the system you are designing..

Hopefully, we all will be able to learn from this..

Tony

1 user thanked author for this post.

Charles Brown

[Rob Schepis]

All this “info” is simply that and really proves nothing. I think Tony’s 35+ years of actually building systems and outfitting boats and watching over them for decades is what really matters for the test of time. All else is just “information”

1 user thanked author for this post.

Charles Brown

[Author]

Replies