Putting An End To This

September 29th, 2009

Installing Fittings The DMP Way

We’re sure most of you understand the concept of the “weakest link.” When it comes to hoses and hardlines running throughout your vehicle, that potential weak link can exist in the ends and fittings. Hoses today have a burst point that exceeds the usual pressure they previously operated at. Unless there is a weak spot due to rubbing on a hot or sharp surface, chances are the hose will not fail for a long while.

The fittings found at the ends of those hoses, however, serve a dual purpose. They must connect the ends to another piece, and must do so without losing any line pressure. We went to DMP Fasteners in Chatsworth, Calif., to get the end-all, be-all of attaching fittings to hoses and hardlines.

DMP Enterprises was started in 1991 as a custom metal polishing shop called Distinctive Metal Polishing. While it still offers polishing services, DMP has transitioned into a well-stocked hose, fitting and fastener outlet. Offering a complete line of XRT fittings, Kugel Komponents line clamps, Jiffy-Tite connectors and various hardware items, DMP is a one-stop shop for those in the need of hose, hardline and fittings. One of the things they sell is from Koul Tools, which are tools that allow easy fitting of braided steel hose into aluminum and AN-style end fittings. They work with XRP, Earl’s, Fragola and other manufacturers’ pieces, so well, in fact, that being stabbed by one of the braided wires is a thing of the past.

Follow along as Derek Stankovich, owner of DMP Fasteners, provides us with a fitting end.

Sources
DMP Fasteners
9520 Owensmouth Ave. Unit 2
Chatsworth, CA 91311
818.775.9804
www.dmpfasteners.com

Koul Tools
2447 Wood Ln.
Lake Havasu City AZ 86406
928.854.6706
www.koultools.com



DMP Fasteners stocks all XRP fittings, pre-made hose kits, carburetor hose assemblies and Jiffy-Tite connectors.

DMP also carries a complete line of stainless T-Bolt hose clamps, worm gear-type clamps and other fasteners designed to connect hose ends.

DMP even has these Gates Power Grip heat shrink-style clamps, which act like huge heat-shrink tubes for radiator hoses.
DMP will happily plumb cars, as well. They are currently working on this HEMI-equipped ’29 Ford Sedan. Koul Tools offer these cool tools that make fitting braided steel hoses into end fittings amazingly easy. Made from sturdy glass-filled nylon, the Koul Tools are available in three different kits and offer a “Hot Rod” kit that covers sizes -6, -8 and -10, along with sizes most associated with automotive lines. DMP uses a chop saw equipped with a specialized blade to cut its braided steel lines. For those at home, the old electrical tape-single jack-chisel method works, too.
With the Koul Tools housing split, the fitting end is installed. Using a vice, the housing is clamped into place. By using a clockwise twisting motion, the braided line will, believe it or not, slip easily into the Koul Tools housing and into the fitting.
With no errant braids poking out, the hose is in the fitting and ready to go. When bending the hardline, the tools of choice for DMP are the imperial tubing benders. There are many sizes, but for most auto applications, the 1/4-, 3/8- and 1/2-inch units are most often used.
To begin, the indicator lines are, well, lined up.
With steady pressure on the handle, the tubing is bent to the desired angle. A belt sander ensures the end is square and free of burrs. To de-burr the interior of the tube, a reamer is inserted.
To ensure the flair is of the correct height, the tubing is inserted approximately an 1/8-inch into a Rolo-Flair flairing tool and clamped in place. The flairing tool is self-centering, so simply turning the handle will cause the tool to flair the end of the tubing to the desired 37 degrees. With the nut and sleeve in place (by the way, don’t forget to install the sleeve and nut onto the line before you flair the tubing), the connection is ready.
Since the Teflon braided steel brake line requires higher operating pressure (3,000 psi and a burst pressure of 12,000) the ends require something more. In this case, a brass “olive” actually goes between the braid and the Teflon tubing. To get the braid out of the way, the line is forced over a separating tool, which separates the braid from the internal Teflon line. The olive is placed over the line and inside the braid. Again, don’t forget to slide the nut over the braided line before spreading the braid.
A hard surface is used to seat the olive.
Lubrication is applied to the end of the hose end. With the hose end in a “soft jaw”-equipped vice, the braided line is forced over the hose end. A wrench is used to tighten the nut, which secures the olive in place.
With that, this compression-type of fitting is ready. Though it amazingly doesn’t use hose clamps to keep the ends on, this type of push-on fitting will withstand pressures of up to 250-psi constant and 1,000-psi burst pressure. It will work with fuel, water or oil. It couldn’t be any easier to assemble. Simply hold the fitting with the soft jaws equipped vice and lube the barbs of the fitting.
Slide the hose over the fitting and that’s it. The tubing is CPE elastomer, textile braid reinforced with CPE elastomer cover. Even without any clamps holding the fittings on, we defy you to pull it back off. We tried while the fitting was still in the vice, and couldn’t do it. For those who feel better with a clamp, or in this case, crimp, there is the XRP HS-79 with Hypalon aerospace-approved hose. With Nomex and Kevlar construction, this is what the NHRA, and possibly NASA, guys use.
Again, the fitting is lubed up prior to installation. There is an end ridge on the collar, and that fits over a ridge on the fitting. The collar has to be over this ridge before crimping, as this adds to the stability of the fitting. Doing the actual crimping is the XRP hydraulic Crimping Device. When the pressure is applied, dies within the device constrict, and crimp the collar in place.
With a force of 5,000 psi, the collar is compressed in place using the crimping device. Thanks to the lube, the fitting can still be clocked into the desired position even after the collar is clamped in place.
Notice how the end of the collar is flush with the fitting, thus ensuring that the two ridges are perfectly aligned.
For hoses close to a heat source, such as headers, DMP covers the hose with an XRP Fyre Jacket. The easiest way to install the sleeve is to use compressed air to expand the sleeve, and then feed the hose into the sleeve. Able to withstand continuous temperatures of 500 degrees, the Fyre Jacket is a silver silicone-coated glass sleeve that gives peace of mind even when things get hot.
DMP also offers what are called Jiffy-Tite connectors. These connectors are perfect for racers, and work with fuel, oil and water lines. They come in valved or non-valved configurations, and are available in -3 to -12 AN 37-degree fittings and male O-ring boss (ORB) thread sizes. DMP offers these ready-made Jiffy-Tite transmission lines.
DMP recommends that to keep from damaging the delicate fittings, only aluminum-anodized wrenches should be used on aluminum fittings.

Advertisements

Leave a Comment

You must be logged in to post a comment.