I posted this over on Comp D in PureFlow's section but have yet to get a response. Maybe some of you guys can provide some insight and knowledge.

I'm purchasing an Airdog II 165 and plan on using 1/2" 316 stainless steel tubing to replace the blue Parker hose that comes in the kits. I've already spoken with Josh at Airdog regarding this but I want to hear clarification from another Airdog rep and maybe from those who are just as knowledgeable.

The 1/2" tubing I got actually yields closer to 3/8"-7/16" ID. When speaking with Josh, I asked if this would affect the pump's operation in any way or if it would somehow void the warranty with the pump. The short, quick response I got was just, "No." I had a VE pump custom built and the builder tells me that 3/8" should still supply more than plenty of fuel that is demanded by the pump and that 20-30psi of inlet pressure is recommended.

Referencing the following chart in the linked thread, if I were to run 25psi of inlet pressure, would this essentially make the 165 work more like a 108gph??

ADII 165 Flow Ratings
PSI ---- GPM
30 ----- 1.69
20 ----- 1.93
15 ----- 2.0
10 ----- 2.16

I also asked for the thread size in the pump base for the suction, supply and return lines. I was told, to quote Josh exactly, "1/2" NPT by 3/8" for both suction and supply and "3/8" NPT by 1/8" for the return line. I was hoping to get a thread pitch to be sure I get the correct fittings but I assume NP threads are pretty standardized. To be honest, the tone in Josh's monotone voice sounded like he wasn't too enthused about his job or even seemed like he was willing to answer any more than the questions I asked. I was quite displeased with this but I got answers nonetheless.

To sum up, I want to be 100% sure that there will not be a single issue with the pump. I'll warrant the tubing and fittings if a leak turns up somewhere, of course.

Feedback?

 

Wouldn't the stainless be prone to cracking from vibration? That is the only drawback I see with the tubing.

 

Another reason for utilizing rubber hose to couple to the injection pump and the AirDog.

 

The stainless will not crack, it is durable (depending on wall thickness).

NPT tube fittings are very common, wont be an issue finding them. One thing you need to remember about tube VS hose, tube has less internal friction so it will actually flow better than the equivalent size hose.

I use all kinds of tubing of various sizes in my job daily at pressure from 0-4000psi with crazy vibrations and rarely have any issues. I also run 1/2'' s.s. on my race car for fuel lines, easily feeds 500hp with a mallory 140gph.

 

^He's right. I thought about it and it would work if it was the right thickness. The brake lines are metal and they don't crack .

 

He did give you the thread pitch. NPT is a standard tapered thread, and you don't have a choice of "fine" thread or "course" thread. The 3/8" ID will be completely fine. Running 25 psi through 3/8" line diameter will take you above 650 hp.

Your 1/2" hose would be better on the inlet side of the pump as it has a larger cross section than 1/2" tube. As I said before, line diameter on the suction side of the pump is most critical.

The 1/2" stainless should be fine as long as all connecting components are mounted and supported well. I've seen stainless crack multiple times from vibration fatigue when the lines or components are not supported. I have a small section of 1/2" stainless on mine from the outlet of the Raptor 150 to the inlet of the dual Fleetgaurd filter head, and it's been fine.

What type of compression fittings are you going to use? Are you going to bend the tubing yourself? Have you ever done something like this before?

--Eric

 

Thanks, Eric. I was just wanting confirmation on the thread size is all. I figured NPT didn't vary any. Yes, I'll be doing the bending myself and I've bent tubing before. I'm in no hurry to get this done and therefore will take my time to be sure I do things correctly and properly.

I can get 3/4" OD stainless tubing if I really wanted to for the suction side of the pump. I'll be using Swagelok compression fittings like the one pictured below. Is that what you're asking?

 

3/4'' is way overkill in my opinion and bulky. Swagelok are great fittings, much better than parker. Be sure to use proper benders and have fun!

To properly tighten swagelok fittings of that size, bottom tube in fitting, turn nut handtight, turn nut another 1-1/4 turns (or 7 nut flats is what i do).

Also, be sure the ferrules are on correctly!

 

Yup! I was going to recommend Swagelok if you didn't already have something in mind. We keep ~ $150k worth of Swagelok fittings in stock and work and use them daily.

The fittings you'll want for the inlet and outlet are probably SS-810-1-8BT (http://www.swagelok.com/search/find_...7-a5d3fd3672c3). These are 316 Stainless male connectors, 1/2" male NPT x 1/2" Swagelok tube fitting. The "BT" designation on the end of the part number makes it a "bored through" fitting that will have a larger internal diameter, and thus better flow characteristics. With a BT connector, there is no "shoulder" to butt the tubing against, so just make sure you have plenty of tube penetration for the ferrules to seat properly.

With < 650 hp of fueling from your VE, you'll be completely fine with 1/2" tubing. I assume you are going to use some flexible hose for the connection to the VE itself to allow for engine movement?

Post up pictures along the way of your install...

Eric

 

That is exactly what I had planned on was cutting the blue Parker hose that comes with the Airdog and using it between the injection pump and tubing as well as between the Airdog and tubing on both suction and supply sides. I'll double flare the tubing to create a barb for the hose to grab hold of. I just need to get the proper 90* fitting in the VE to adapt to the compression.

The Swageloks are what I already have. They aren't the bored through type as you describe though. They have the shoulder on the inside that the tubing butts against. The bored through type sounds like they would be nice. Though, I don't imagine there would be that much of a difference but then again, I wouldn't know. I could try measuring the ID of the fitting for comparison if I could find the ID of the bored through fittings. When setting the ferrules, I've always butted the tubing and pulled it back out 1/16"-1/8" as to allow the ferrule to do the sealing and not taper the end of the tubing.

EDIT: I scanned through Swagelok's catalog and found some dimension. The standard 1/2" NPT to 1/2" straight male connectors, like the ones I have, yield an ID of 0.41".

 

I am not sure if you are saying the fittings that thread into the ve are npt or not. I am pretty sure they are metric thread.

 

No, you're right, Bill. I was just stating that I need to find the correct 90* fitting to go into the VE to adapt to the 1/2" tubing. I know it's M12 x 1.5 thread in the VE.

 

Would something like this work? 32MM-12-4http://fittingsandadapters.com/malmettofemp.html

And then use SS-810-2-4?

--Eric

 

I don't know that a 90* fitting would have the clearance to thread into the pump. I think the best option would be to find a straight M12x1.5 to 1/2" OD tubing and just put a 90* in the tubing.

I like the idea of the positionable fitting but haven't been able to find one with the metric M12x1.5 thread on the other end. http://www.swagelok.com/search/find_...10-2-4PR&item=

 

also cuttingn the pipe square is crucial as well as not collapsing the pipe by cutting it with one of those home depot cutters , it sucks when the line you just put on trys to give you a shower