fuel manifold installation

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Bmarler said:
Absolutely. You need to develop a sense of how the fitting is seating in the threads. It should get progressively harder to turn, and you develop a sense of how much pressure to exert on the wrench. When you feel it turn without a gain in pressure, you’re slipping the threads and compromising the connection. Just like tightening a bolt till the head pops off.
There’s more latitude putting brass into steel than when doing brass to aluminum. Aluminum is very soft and requires a softer touch. Use the tape, then sealant approach and you’ll be fine. Be absolutely certain you leave the end threads bare so you don’t get debris in the fuel system.
Also, use care with the fittings you linked. Those type are free to swivel after installation and depend on an o ring to seal. Those are more prone to failure. I wouldn’t choose those for my fuel system.
Click to expand...

ok, i didn't notice the swivel feature of the barb
need to look further
 
paulga said:
ok, i didn't notice the swivel feature of the barb
need to look further
Click to expand...

Yes it does. It’s hidden inside the fitting so it can rotate freely after installation.
 
If the spacing of the manifold is too tight for the elbow to clear the neighboring fitting, you can put a nipple in every other hole so they are at different elevations. Install the low ones first, then the taller ones.
Hopefully you’re planning on valves before the elbows.
 
Bmarler said:
Yes #8. I don’t know why I keep thinking #12. I will edit my posts for future searchers.

Ok, my previous post linking the fitting was too old to edit. Here’s the #8 to 3/4 hose barb adapter.
https://www.discounthydraulichose.c...w-8MOqVkTufNAwXHMdgq8u4dS6ISbp2IaAh_fEALw_wcB
Click to expand...


i saw this table online. does it not say SAE #12 is 3/4" thread?

Screenshot 2024-01-22 213024.jpg
 
My sincere apologies if I led you to buy a wrong fitting. I was thinking trade size, not thread size.
 
Bmarler said:
My sincere apologies if I led you to buy a wrong fitting. I was thinking trade size, not thread size.
Click to expand...

not at all. i'm still looking at the manifold.
btw, could you share a link to 1/2" ball valves?
 
Thanks.
this style ball value may be easier to install

https://shop.keenanfilters.com/products/3-valve-fuel-water-manifold

Bmarler said:
Maybe something like this could work. You just need to check clearance to rotate them into the manifold.
https://www.amazon.com/2-inch-NPT-9...-lpcontext&ref_=fplfs&psc=1&smid=AL09J9CKIG9A

I found some really compact 316 stainless valves too but they are steam rated, and they didn’t list the sealing material so I couldn’t recommend for fuel.
Click to expand...
 
paulga said:
This one has male npt also cheaper.

Forged brass is rated for diesel, right?
Click to expand...

Lead free brass is usually aimed at potable water systems. Certainly the brass is fine for diesel, but it’s the sealing materials that aren’t known in this case. Always buy something specifically rated for diesel fuel to be safe.
 
Bmarler said:
Lead free brass is usually aimed at potable water systems. Certainly the brass is fine for diesel, but it’s the sealing materials that aren’t known in this case. Always buy something specifically rated for diesel fuel to be safe.
Click to expand...

guess the seal material is mostly PTFE, which is good for diesel

like this one:
https://www.grainger.com/product/1W...o7hObCFL0LCXNjrRnc0aAh17EALw_wcB&gclsrc=aw.ds

or this one:

https://www.grainger.com/product/AP...-6GD23?opr=PDPRRDSP&analytics=dsrrItems_1WMH5
 
paulga said:
guess the seal material is mostly PTFE, which is good for diesel

like this one:
https://www.grainger.com/product/1W...o7hObCFL0LCXNjrRnc0aAh17EALw_wcB&gclsrc=aw.ds

or this one:

https://www.grainger.com/product/AP...-6GD23?opr=PDPRRDSP&analytics=dsrrItems_1WMH5
Click to expand...

in addition to the seat material, there's an o ring or other packing in the valve stem to consider. it can be very difficult to find out that particular detail, but before purchase, i would use that criteria for selection as well as the seat material.
 
a valve with a wog rating would be for water, oil , and gas.
 
i read abyc h-33 for diesel fuel recommendations and the only valve reference i found was this:
g. Valves
(1) Manually operated valves shall be designed with positive stops in the open and closed
positions or shall clearly and plainly indicate their opened and closed positions.
(2) Spring Valves - Tapered plug valves with an external spring shall not be used.

just something to consider. materials of construction aren't mention in regard to valve body or seals. maybe there's another publication referencing it.
i'll keep on the hunt for valves for you as i get free time.
 
Bmarler said:
gets bad reviews about thread design. keep looking.
Click to expand...

I guess the webstone valves may work fine. It seals water then it should seal fuel as well

I saw two variants of manifold, the only difference to me is the size, one is 1.5" x 1.5", the other is 2" x2". I prefer the slim one, but is there any reason to consider the 2"x2" version?

1.5x1.5 :

https://www.mcmaster.com/product/5975K44

2x2:
https://www.mcmaster.com/product/5469K203
 
paulga said:
I searched for the nipples on mcmaster for use with "diesel fuel", all these have BSPT threads

https://www.mcmaster.com/products/n...ure-stainless-steel-threaded-pipe-fittings-8/

this 1/2" NPT nipples is brass, it says water and oil, so there should be no issues with diesel, correct?

https://www.homedepot.com/p/Everbil...MeS6-EhNOkKrHXcKxMYaAh1-EALw_wcB&gclsrc=aw.ds
Click to expand...
Due to the possibility of diesel dissolving zinc, purists may avoid any alloys
containing zinc, as brass does.
I have found that any metal will be compatible except galvanized iron or steel.

I have used Home Depot piping when that was all I had but your manifold is a
one-time build that may benefit from using a better quality of components. For
example, I like to use hex nipples on something like this even though they cost
a bit more.

McMaster-Carr sources their pipe components domestically, AFAIK, and should
have better quality control than what I've found at HD.
 
Last edited:
KnotYet said:
While purists may avoid any alloys containing zinc, as brass does,
I have found that any metal will be compatible except galvanized iron or steel.
I have used Home Depot piping when that was all I had but your manifold is a
one-time build that may benefit from using a better quality of components.

McMaster-Carr sources their pipe components domestically, AFAIK, and should
have better quality control than what I've found at HD.
Click to expand...

Thanks, that makes sense

mcmaster's filtering is complex. when I filter for diesel use, all valves have BSPT threads

I'll probably get this

https://www.dudadiesel.com/choose_item.php?id=ISO-nipp050


just curious, how is a "close nipple" tightened without a hex or square shape for grip?
 
paulga said:
Thanks, that makes sense

mcmaster's filtering is complex. when I filter for diesel use, all valves have BSPT threads

I'll probably get this

https://www.dudadiesel.com/choose_item.php?id=ISO-nipp050


just curious, how is a "close nipple" tightened without a hex or square shape for grip?
Click to expand...
It gets tightened when the mating components are screwed tightly together.
The issue will be removing it if needed. That's when the threads may be damaged.
 
when I look for a 1/2" male npt to 1/4" female npt fitting, I'd find the home depot part in my search.
it has a hex outside for gripping.

does McMaster-Carr have lower defect rate than home depot?


KnotYet said:
Due to the possibility of diesel dissolving zinc, purists may avoid any alloys
containing zinc, as brass does.
I have found that any metal will be compatible except galvanized iron or steel.

I have used Home Depot piping when that was all I had but your manifold is a
one-time build that may benefit from using a better quality of components. For
example, I like to use hex nipples on something like this even though they cost
a bit more.

McMaster-Carr sources their pipe components domestically, AFAIK, and should
have better quality control than what I've found at HD.
Click to expand...
 
paulga said:
when I look for a 1/2" male npt to 1/4" female npt fitting, I'd find the home depot part in my search.
it has a hex outside for gripping.

does McMaster-Carr have lower defect rate than home depot?
Click to expand...
The answer is it depends. Probably lower overall for most items but for something
as easy to get right as a plumbing fitting, any difference is unlikely to matter.
 
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