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AN fittings with Port for Pressure Measurement

steve murray

steve murray

Well Known Member
In the process of installing SDS fuel injection system, need to monitor the fuel pressure and not real excited about having a bunch of fittings\adaptors to do this. Found this site that has AN fittings with female sensor port. This should help me eliminate a lot of fittings and\or long hose. Curious if anyone else has used these type fittings?


http://www.anhosefittings.com/fittings/sensor-adapter-fittings.html?SID=qr003ae4i9b63p1cdhr4klk1eb

They also they had fire sleeving at much lower cost than spruce.

Ordered some parts, will update once I receive and inspect parts.
 
Summit racing is a pretty good place for fittings. I have seen the fittings with pressure ports there before.
 
Not sure what your specific system architecture looks like, but both the SDS fuel pump module and their recommended (Borla) regulator have multiple unused ports which can be used to feed a pressure transmitter. Beyond a simple reducer, no adapter needed.
 
Now THAT is a useful website. Thanks! For my fuel pressure takeoff I had to have a steel AN2 fitting TIG welded to a steel SAE Tee.
 
The auto racing stuff isn't any cheaper than AN stuff bought from one of the big aircraft vendors. But sometimes they have some unique stuff that works a bit better.
 
Toobuilder said:
Not sure what your specific system architecture looks like, but both the SDS fuel pump module and their recommended (Borla) regulator have multiple unused ports which can be used to feed a pressure transmitter. Beyond a simple reducer, no adapter needed.
Click to expand...

Hey Michael

I am installing the SDS system and have the fuel manifold (with several open ports) located on the top of the engine but did not really want to run another small fuel line for pressure measurement back to the firewall. I was looking at the Borla regulator from Ross, is the plug on the side removable\useable....I was going to call Borla. Also, do you know if regulatory mounting orientation is critical?

Thx

Steve
 
The Borla unit I have has two outlet ports (it's a "T" configuration). I my case I have a bulkhead fitting as the fuel outlet through the firewall, and the other side has a reducer and the transmitter screws right into that.

Edit, I drilled and tapped the cap provided with the regulator... It's simply an AN plug.
 
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Toobuilder said:
The Borla unit I have has two outlet ports (it's a "T" configuration). I my case I have a bulkhead fitting as the fuel outlet through the firewall, and the other side has a reducer and the transmitter screws right into that.

Edit, I drilled and tapped the cap provided with the regulator... It's simply an AN plug.
Click to expand...


Hi Michael.

I follow the part about tapping the cap on the regulator but am not following the part about the bulkhead fitting with the reducer. Can you send a picture?

Thx

Steve
 
Have you asked Ross about this? As mentioned there are a few different areas for the sensor to go. Why would you need to run another fuel line from the fuel distribution? I'm about to install the system, so maybe I'm misunderstanding something.
 
Those fittings would come in handy for ground testing an electric sensor against a pressure guage say oil or fuel pressure when the sensor error was suspected. Would make a great tool box item for the A&P.
 
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steve murray said:
Hi Michael.

I follow the part about tapping the cap on the regulator but am not following the part about the bulkhead fitting with the reducer. Can you send a picture?

Thx

Steve
Click to expand...

The salient point of my post was to confirm that the regulator has two ports sharing a common chamber, so both see the same output (fuel rail) pressure.

The part about the bulkhead fitting was just my implementation - not an endorsement. But in short, a standard straight bulkhead fitting has a short side and long side. In my case, I threaded the short side into the regulator, leaving the long side to penetrate the firewall. Made for a clean way to mount the regulator, that's all.
 
majuro15 said:
Have you asked Ross about this? As mentioned there are a few different areas for the sensor to go. Why would you need to run another fuel line from the fuel distribution? I'm about to install the system, so maybe I'm misunderstanding something.
Click to expand...



Hi Tim

The fuel manifold from Ross for my installation has a lot of open ports but the block itself sits on top of the engine. I am trying to avoid placing the fuel pressure sensor on the engine due to high vibration area. In order to get a pickoff spot to measure the fuel pressure, I could put a line from manifold block (that sits on top of the engine) back to the firewall where I plan to install the pressure sensor or use some type fitting on\around the regulator to access the fuel pressure.

I am going to pursue the earlier post about removing the plug on the Borla regulator and using that as a pressure pickoff port. I have a call into Borla to make sure I am not overlooking something.

Take care

Steve
 
I gotchya now. Yes, I think the pressure regulator option is the best. Ross just sent my install kit out, so please post what you find out. I'd like to do the same. I'd rather have the reading closer to the injectors than the fuel pump outlet itself. Thanks!
 
Most of the ones we have plumbed have used one of the manifold ports, to a hose to the VA168 mounted on the firewall. Pressure sender mounted on the VA168. The manifold is reading constant pressure.
You can tee into the return side line before the regulator, and put the sender there.
Check Earls #100199ERL----6 male and female with a 1/8 NPT female port for the sender.

Tom
 
Why not just use one of the unused ports on the fuel pump module? The output pressure should be the same as at the fuel manifold. Or close enough for government work.
 
It should be... Unless the regulator fails. Moving the transducer on the controlled side of the regulator adds one more element of information for on the spot troubleshooting. After all, the primary consideration is the pressure seen at the injectors.

As for running a line off the distribution manifold... Assuming the regulator is on the cold side of the firewall, the transducer plumbed into the common chamber shared with the injector rail (the "extra" port on the regulator) is hydraulically identical to running a hose from the distribution manifold to the VA 168 pressure manifold, but with less weight, leak opportunity and cost.
No need to make this harder than it needs to be.
 
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Hydraulically it makes no difference where the regulator is physically located, so long as it is downstream of the injectors. The regulator functions by bleeding off excess pressure, so all the fuel lines from the pump output to the regulator are going to be the same pressure. Less some miniscule line losses (or an outright blockage), a pressure transducer screwed into the pump module manifold, the injector manifold, the extra port on the regulator, or a T fitting anywhere in between will all read the same.

In my case I'm using a tubular fuel rail rather than the injector distribution block that Ross offers and the regulator made more sense to mount to the firewall. As long as I was at it, I decided to mount it "through" the firewall which neatly solved the mounting issue and several extra fittings. One step further and flip the assembly around and the regulator is now on the cold side and provides an even better location for the pressure transducer. In my case it was simply packaging synergy.
 
SDS Borla regulator fittings

steve murray said:
… I am going to pursue the earlier post about removing the plug on the Borla regulator and using that as a pressure pickoff port. I have a call into Borla to make sure I am not overlooking something…

Steve
Click to expand...

Yes, you can remove the SAE Straight Thread aka AN ORB (o-ring boss) aka O-Ring Port fitting from the Borla regulator used by SDS and tap it 1/8 NPT for a pressure sensor or you can purchase “-6AN ORB to 1/8" NPT Female“ part number OP-06-02 from https://www.anhosefittings.com/fittings/sensor-adapter-fittings.html I was concerned about wall thickness if I tapped the extant fitting and I can’t say the one from ANhosefittings will be thicker because I don’t have it yet but for $4.90 shipped I figured I’d buy it vs a 1/8 NPT tap and see what it looks like.

  • This eliminates the hose from the SDS injector manifold to the fuel pressure sensor.
  • I plan to swap the o-ring on the ANhosefittings fitting for the one on the Borla fitting on the theory the Borla fitting's o-ring is a more desirable compound.
  • Check your pressure sensor OD to determine how much spacer will be required under the regulator for clearance if you are mounting it on a flat surface such as the firewall.
  • I verified with Borla by email before I removed the fittings. Once you remove them it is clear you can move the inlet fitting from one side to the other or replace either with another fitting.
  • BTW the torque on a -6 Straight Thread O-Ring Boss per Lycoming SSP-1776 Table VI and Van's Manual Section 5.27 is 23 to 24 ft-lbs but I’m thinking that’s for the steel swivel fitting on an engine-mounted fuel pump and I don’t know that fuel pump body material whereas the Borla regulator fittings are aluminum, 6061 T6 I imagine.
  • As pointed out in post 5, fittings from ANhosefittings are not officially AN fittings. But what is AN fitting? AN fitting specs have been obsoleted by JIC SAE J514 which covers 37 deg flared, compression ring non-flared, and o-ring boss fittings. JIC SAE J514 is not available for free so I don't have it. MIL-DTL-18866 says for new design use J514 since 1999. It is fair to question the quality control of whatever parts we purchase of course. As in the OBAM world where we see "experimental only", in the automotive world we see "for off-road use only".
  • ANhosefittings, ImprovedRacing, and RaceFlux seem to be in the same storefront.

Now I'm down to only one sensor on the Van's VA-168 Transducer Manifold so I could remove the VA-168 and run the oil pressure hose to the sensor using:
  • ANhosefittings "1/8" Female NPT to -4AN Male Flare Adapter Fitting" part number PFM-02-04 which is aluminum.
  • For steel, ANplumbing has part number 705004 which is the XRP version of Earl's part number 968704ERL.
  • ANplumbing is a storefront that sells Earl's and XRP.
  • Gotta find a secure way to mount the sensor though. I'm thinking two Adel clamps, one for the sensor and one for the hose, the Dynon 103757-000 aka Sensata/Kavlico P255-150G-E4A sensor is mostly a 1.04" dia cylinder.

BTW the XRP website has a pdf catalog that's good for brainstorming even if you want to purchase official AN fittings elsewhere.

It seems Earl's and XRP are manufacturers whereas the others mentioned are vendors. Earl's sells online and through vendors while XRP sells only through vendors.
.
 
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We've done some like this-----6 on the branch side to the engine, -4 on the run side for the fuel pressure sendor hose. Our same tee we use on the Lycomings.

Tom
 

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  • Regulator and pressure fitting.jpg
    Regulator and pressure fitting.jpg
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I guess I missed this thread before.

We offer 2 types of fuel blocks. In the early days, both the baffle and engine crankcase mount had 1/8 NPT holes for pressure takeoff. As of Feb. 2023, the Lycoming engine blocks no longer has these holes as people we usually not using them. The baffle mount blocks still have the provision and these face conveniently aft.

As mentioned by John and Michael, you can remove the plug from the Borla reg and tap pressure off here.

You could also tap off right at the pump module. There are two 1/4 NPT plugs there.
 
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