Swagelok compression fittings for rigid stainless brakeline?

[317millhand]

What do you guys think about using one of Swagelok's ball valves for a proportioning valve in conjunction with rigid stainless brakelines of course?
https://static1.pt-content.com/images/pt/2009/10/1mpt1485762618adtype1size1x1type3campid5-1.jpg http://cgi.ebay.com/lot-of-2-swagelo...item439af44eac (http://rover.ebay.com/rover/1/711-53200-19255-0/1?type=3&campid=5336121898&toolid=10001&mpre=http%3A%2F%2Fcgi.ebay.com%2Flot-of-2-swagelok-1-4-valves_W0QQitemZ290362511020QQcmdZViewItemQQptZLH_ DefaultDomain_0%3Fhash%3Ditem439af44eac)


It has compression fittings and will handle lots of pressure. My main gripe with parts store prop valves is that they are all made for 3/16 brake line and most of the chevelle pre bent line kits you buy have 1/4 line going to the rear. Have to use too many adapters to get everything together. I know I could have just ran 3/16 line myself but its too late now. already dropped the bucks on a Right Stuff line kit and it fits perfetc. Swagelok also makes an adapter that has a compression fitting on one end for 1/4 tube and 1/8 male NPT threads on the other end and should thread into regular prop valves. Has anyone here used the swagelok compression stuff on brakes before? Hopefully Tobin will chime in with his opinion.

https://static1.pt-content.com/images/pt/2007/05/progress-1.gif

[sunkistcamaro]

I have not used Swagelok fitting on brake lines but I do work with them at my job. These are great fittings, we use them for our instrumentation fittings. I cant remember ever having any problems with them. If I needed to I would use them!

[lipe33]

I use them every day during my work at Caterpillar Engine R&D. We use 1/4" Swagelok fittings for all our pressure instrumentation below 10,000 psi, and some well above. Vibration has not yet been an issue at either the fitting itself or the joint at which the ferrule is attached to the tube. The joint can be separated numerous times for servicing without any problems. You will be pleased with their performance.

[b-man]

I don't know about using compression fittings for brake lines.

I have worked with Swagelok fittings myself for many years, building high vacuum thin-film coating equipment for the semiconductor industry.

I can say for sure a ball valve won't have a fine enough adjustment, it will act like it's either full on or shut completely off.

Personally I would stick with inverted flare brake line fittings. If Swagelok fittings were really good for use in braking systems I would think that a lot of high-end builds would be using them.

[sunkistcamaro]

This is the part your looking at.
http://www.swagelok.com/search/product_detail.aspx?part=SS-1RS4
One problem I could see is the actual flow diameter. The internal passage can be as low as .172" at full open, that may already be to much restriction for your application. But your 1/4" line might be close to that too, I dont know.

You should ask the seller what group fittings these are (0, 1 or 18). Also what stem is inside, that will also limit your flow.
Read the data below
This document shows you the data for each group.
http://www.swagelok.com/downloads/webcatalogs/EN/MS-01-164.pdf

I dont think your going to have a adjustablity issue considering it is 9 turns to full open for what ever group they end up being.

Does anyone know what our brake line pressure is?
These look like they are good up to 5000 psi max at room temp.

[MonzaRacer]

Consider this, if its a compression fitting, it MUST be DOT certified as well as FMVSS and a whole host of other certifications, if you have more than a $1000 in car (and I am quite sure you do) I wouldnt ever think of using a non brake approved connection as the liability is too great. Think of it this way, your driving your car, first day of year, just short cruise, and this part, not actually approved for motor vehicle use, is installed and one person gets hurt/killed/disabled and your on the line,,,and the appropriate person see's this non automotive use item, reports to lawyers, your insurance, DMV, etc. So now your on the hook for hundred of thousands if not millions of dollars and maybe even decades of grief, heck you may even have similar issue to my a lawyer that can suspend my license at drop of a hat, no warning.
Pass.
As for what can be used NAPA sells a steel compression fitting that is the only thing in compression that can be used/ is legal and mis installation is only thing your on the hook for.
Use at your own discretion. BUT think of liabilities before doing so.As for an adjustable prop valve I would rather use something rated for brakes, if a company sells a piece it puts liability on THEM, not you if it fails.
I have found several Ford rear axle line kits have a tube nut that fits 3/16 line but threads in where a 1/4 line fits. I would see if you cant get one of these and make a short adapter line and use a regular Inverted Flare Union to mate it,,,,hmmmm might see if I can make some of these, I have gotten creative with my hydraulic flaring tool (hehe) lately.

[Jim Nilsen]

with the Willwood valve only being $35 to $45 why would you use anything else? The liability is theirs and the fact that they are specifically designed to do the job right is worth more.

When proportioning valves used to be almost $100 it was a toss up to do other things, but now it is almost sensless to use anything else. They weigh next to nothing and the space they take up make them easy to put anywhere you want.

Do not use a ball valve as they are only able to control flow and not pressure.

[Apogee]

I agree with Jim for the most part. The Swagelok valve you linked to is primarily designed for flow regulation, not pressure. There is certainly a pressure drop across the valve, however that varies by the setting and does not produce a linear pressure curve similar to that of a PV. A PV has a spring, the preload of which is what determines the knee-point of the pressure curve. The knee-point is the point at which the front to rear pressure relationship stops being 1:1 and the rate of pressure increase to the rear brakes becomes proportionally less as defined by the shape of the armature. Even in an adjustable proportioning valve, you don't change the slope of the rate of pressure increase to the rear brakes, only the pressure at which it activates.

Most of the aftermarket proportioning valves that I'm aware of are aluminum and ported for 1/8-27 NPT fittings and typically come with the 1/8NPT to 3/8-24 SAE inverted flare adapter fittings. I understand there are limited fittings options for 1/8" NPT, however I have seen a few larger than 3/8-24...just not the 7/16-24 you were probably hoping for. I know that BrakeQuip sells a 1/8 NPT x M12 ISO (BQ246) that might work...I'm just saying there may be some options for you that would not require a bunch of adapters to make it work.

In addition to the functionality issues, I have some concerns about the reliability of compression fittings in such an application. While not automotive, I've seen or heard of enough industrial failures where vibration and temperature variations were present to not want to take the chance on a car.

Tobin
KORE3

[oestek]

Consider this, if its a compression fitting, it MUST be DOT certified as well as FMVSS and a whole host of other certifications, if you have more than a $1000 in car (and I am quite sure you do) I wouldnt ever think of using a non brake approved connection as the liability is too great. Think of it this way, your driving your car, first day of year, just short cruise, and this part, not actually approved for motor vehicle use, is installed and one person gets hurt/killed/disabled and your on the line,,,and the appropriate person see's this non automotive use item, reports to lawyers, your insurance, DMV, etc. So now your on the hook for hundred of thousands if not millions of dollars and maybe even decades of grief, heck you may even have similar issue to my a lawyer that can suspend my license at drop of a hat, no warning.
Pass.
As for what can be used NAPA sells a steel compression fitting that is the only thing in compression that can be used/ is legal and mis installation is only thing your on the hook for.
Use at your own discretion. BUT think of liabilities before doing so.As for an adjustable prop valve I would rather use something rated for brakes, if a company sells a piece it puts liability on THEM, not you if it fails.
I have found several Ford rear axle line kits have a tube nut that fits 3/16 line but threads in where a 1/4 line fits. I would see if you cant get one of these and make a short adapter line and use a regular Inverted Flare Union to mate it,,,,hmmmm might see if I can make some of these, I have gotten creative with my hydraulic flaring tool (hehe) lately.


Unfortunately, we always have to be thinking this way. Good post.

[317millhand]

https://static1.pt-content.com/images/noimg.gif

Heres what Im looking at right now. I do totally agree that the ball valve would be a bad idea, but I would like to have an adapter to go from 1/4 tube to 1/8 NPT. Seems like the brake component manufacturers would make these or make prop valves for use with 1/4 line. With this summit prop valve I have a total of 6 threaded connections to worry about when using 1/4 inch line. I do alot of instrumentation work at refineries and power plants and have yet to see a swagelok fitting fail, but that doesnt mean they wont. Once the ferrules are compressed on they cannot be removed without cutting the tubing.

[nullshine]

Being that NPT seals by bottoming/crushing threads together, I don't think you'll be able to go straight from 1/8" NPT to 1/4" tube... no way to (easily/conveniently) seal the gap between the fitting and the tube (at least not that I know of, excepting a compression fitting).

You could ditch one adapter per side by going with these 1/8" NPT male to 7/16"-24 female adapters. (7/16"-24 male are the flarenuts you're using on your 1/4" lines right now, right?). It's a brass fitting, so you should avoid having leakage as some members report when using stainless-stainless connections, and it's listed as a brake line part.

http://store.fedhillusa.com/ad4br.aspx

Hope this helps.

[megaladon6]

i think you could definitely use swagelok's tubing and fittings, but it's major overkill. i would not trust the ball valve to be accurate for all the aforementioned reasons.
swagelok makes their stuff for high end, precision, and/or high purity work. way beyond any car in the world, including F1.

[Apogee]

http://store.fedhillusa.com/ad4br.aspx

Ding, ding, ding...we have a winner. For some reason I was only finding metric equivalents of the fitting linked to above earlier, but that will take you from NPT to your standard 1/4" tube nut straight away.

Tobin
KORE3

[317millhand]

Being that NPT seals by bottoming/crushing threads together, I don't think you'll be able to go straight from 1/8" NPT to 1/4" tube... no way to (easily/conveniently) seal the gap between the fitting and the tube (at least not that I know of, excepting a compression fitting).

You could ditch one adapter per side by going with these 1/8" NPT male to 7/16"-24 female adapters. (7/16"-24 male are the flarenuts you're using on your 1/4" lines right now, right?). It's a brass fitting, so you should avoid having leakage as some members report when using stainless-stainless connections, and it's listed as a brake line part.

http://store.fedhillusa.com/ad4br.aspx

Hope this helps.
Thanks for the help. Someone over on the chevelle site also posted a link to the same adapter from speedway motors and I went ahead and ordered 2 of them. For some reason I was not able to find one on my own. You guys rock. I still think the Swagelok compression fittings would be great BUT THEY DO HAVE TO BE USED WITH THE CORRECT TUBING. And they will not pass inspection in some states either. This rigid stainless tubing is hard to flare unless you have the correct tool (which I do have the Mastercool now)

[JRouche]

I use them every day during my work at Caterpillar Engine R&D. We use 1/4" Swagelok fittings for all our pressure instrumentation below 10,000 psi, and some well above. Vibration has not yet been an issue at either the fitting itself or the joint at which the ferrule is attached to the tube. The joint can be separated numerous times for servicing without any problems. You will be pleased with their performance.

Umm, I for one have to say thanks for showing up here. I have alot of respect and comfort with using any of the Cat line on my car. For me the fasteners. And if I had an opportunity to use any flex hydraulic lines supplied by CAT I would.

You car guys ever want a solid part and cant find it in the car catalog dont forget our heavy industry manufactures. Beats the hell out of the off shore suppliers.

I just wanted to give a nod to the guys at Caterpillar.

Keep up the honest work and quality parts at a decent price. I will always be a customer... JR

[lipe33]

Thank you for the kind words friend. I am simply trying to help a fellow enthusiast. With that being said, I am a professional R&D mechanic, not an engineer. I cannot speak to whether the parts in question are DOT approved, or if they were designed for the uses they see within the R&D lab.

The Swagelok hardware we use are not Cat parts, but genuine Swagelok fittings. However, that does not mean it does not make its way onto production iron.

My facility does all the diesel engine R&D for North America. We test everything from inline six cylinder C7/9 series engines all the way up to twenty cylinder 3520 series engines, as well as several experimental engines between those bore sizes.

We have not seen any mechanical failure due to vibration or extreme pressure with any Swagelok fittings during my time at the Tech Center. However, as previously mentioned by a fellow member, I do not know if using such parts would stand up to legal scrutiny should, God forbid, something happen.

I will speak to the tooling and machining foreman about the specs of the 1/4" unions we use. More info to follow.