Anatomy of Couplings
Hose Extraction



Many years ago I was lucky enough to make the acquaintance of a man named Joe Fischelson.  Joe took the time to teach me how to couple fire hose.  The technique he taught is fairly straight forward and simple.  It uses no measuring tools other than the pressure gauge on the coupling machine.  I have seen many people couple hose but very few use these short cuts.

Before attempting to couple fire hose one must understand exactly what an expansion ring coupling is as well as the various parts and their names.  If you are not familiar with them, please click here.

To see more information on hose coupling machines, click here.

If you are reusing couplings you must first extract the hose and expansion ring.  To see this procedure, click here.

Now, on to the the project at hand.


First, locate the correct drawbar and segment assembly.  Each size of hose uses different segment assemblies but some sizes use the same drawbar.  This picture shows the assemblies used for (left to right) 1" forestry hose, 1-1/2" hose, 1-3/4" hose, and 2-1/2" hose.  As you can see, there is quite a difference between the various sizes.  Expander and Drawbar Assemblied for Hose Coupling Machine
1-1/2" Expander and Drawbar Installed on Coupling Machine Properly install the assembly on your machine according to the manufacturer's instructions.  On our machine there is an adapter that the drawbars attach to within the tool holder.  The adapter has an adjustment mechanism that can drastically change the final product.  It must be inspected before each use to make sure it is tight and has not moved.  It seldom is a problem but has the potential to be one.  If it is not adjusted correctly you will get the impression that you are fully expanding the ring when you are actually just bottoming the cylinder out.

If you are not sure about the stroke adjustment, there is a step in the adjustment section that will help troubleshoot things.

Cut the hose in a straight line.  It doesn't have to be perfect but why take a chance.  Use a sharp utility knife for best results.  The sharper the better.  If you have to make several passes to cut all the way through the hose the ends will unravel and you will have to trim a lot in the next step. 1-1/2" Fire Hose Being Cut for Recoupling
Trimming 1-1/2" Double Jacket Fire Hose After Cut Trim any loose threads.  Again, it doesn't have to be perfect but the cleaner it is the less chance of problems.   Loose threads may not result in a leak but they will get in your way as you are coupling the hose.
Now it is time to adjust the machine to your coupling.  This should be done with every individual coupling.  The only exception to this is if the machine maker is the same as the coupling maker.  In our case we use a Red Head brand machine.  When using Red Head couplings we can grab either part of the coupling to set the machine and it will be set for the other end.  If you are uncertain about either part of the equation, set up the machine for each coupling you attach.

Retract the machine completely until pressure rises on the gauge.

Foot Switch for Coupling Machine
1-1/2" Couplingl Being Slid Onto Coupling Machine Remove the tail gasket!  Never attempt to adjust the machine when a tail gasket is in place.

Turn the adjusting nut (the knurled nut the coupling slides up to) clockwise until it stops.

Slide the coupling onto the drawbar.

Hit the expand pedal and jog the machine until the coupling will not slide off of the drawbar assembly.  Pull on the coupling as if you were removing it.  The result should look like the picture to the right. Coupling Being Held on Machine While Tool is Being Jogged
Coupling and Adjustment Nut Properly Set While holding the coupling against the stops on the drawbar, turn the adjusting nut counter-clockwise until it contacts the coupling and then turn it clockwise until the coupling is free to move.  (Usually about 1/4 to 1/2 a turn)

The larger this gap is, the more of the gasket that will be forced out between the expansion ring and the coupling up to the point where the entire tail gasket can be forced out.  Too small a gap might cause the segments to grab part of the coupling if the operator doesn't hold it snug against the stop while coupling.

As an extra safety measure, expand the segments until they either touch the coupling or the cylinder bottoms out.  If the segments touch the bowl you are definitely good to go.  If not, look into the bowl to make sure the segments have expanded enough to trap the hose with the expansion ring.  If it looks questionable, grab the manual and reset the drawbar stroke setting.

Now, if everything is O.K., retract the drawbar and remove the coupling.

Now, insert the tail gasket being sure it is fully in place. Tail Gasket Being Installed into Coupling
Foot Switch of Coupling Machine Locate the chart that came with the expander and find out what pressure you should be using for the coupling and hose you are working with.  In this case we are coupling 1-1/2" double jacket hose with aluminum couplings.  Our chart calls for 1000 PSI on the gauge.

Step on the retract pedal.

While the retract pedal is held down the pressure will build until the relief valve stops it.  While holding down on the retract pedal adjust the relief valve until you have the setting required. Pressure Being Set on Coupling Machine
Expansion Ring Properly Set on 1-1/2" Expander and Drawbar For standard sizes such as 1-1/2" and 2-1/2" place the expansion ring on the segments as shown.  It is hard to see in the picture but the end of the expansion ring facing the operator is beveled.  This will help the hose to slide over the ring as you assemble the coupling.

(1-3/4" and 3" hose with couplings that reduce to 1-1/2" or 2-1/2" threads are handled different.  When using reducing couplings the expansion ring is placed in the hose and the coupling is installed on the hose before pushing the hose onto the machine.  The operator must be very careful to make sure all parts are exactly where they need to be before pushing onto the drawbar assembly.)

Place the hose into the bowl of the coupling all of the way to the tail gasket.  Make sure the hose does not cover the tail gasket.  Push the hose and coupling onto the drawbar assembly as a single piece, all the way to the adjustment nut.  Do not pull anything backwards.  If you do, start over.  Pulling backwards will move the expansion ring on the segments and will cause problems.

When working with double jacket hose it is important to be sure the liner does not slip backward into the outer jacket.  The fastest solution is to kink the hose about a foot back from the coupling while pushing toward the machine.  Another method is to staple the liner to the outer jacket in a few places that will be beneath the ring when expanded.  The staples will not cause any problems as long as the ring and gasket are in their proper places.

(Note where the thumb is.  It is pushing against the expansion ring to make sure it is all the way forward.  This is a habit from installing reducing couplings and is not necessary when coupling standard sizes.)


Hose and Coupling Being Properly Located for Installation
Expand Being Engaged on Foot Switch While holding the coupling and hose assembly snug against the adjustment nut press the expand pedal.
Once the pressure on the gauge has settled to the preset pressure, hold it for about a few seconds.  Then, release the pressure and turn the coupling about 5 degrees and set the coupling again. Proper Pressure Has Been Hit While Recoupling 1-1/2" DJ Fire Hose

Now, there is only one thing left to do.  Test the hose!  Always make sure the hose is tested before it is put back into service.  People's lives depend on this stuff and you don't want to let them down!



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Copyright 2006 David's Fire Equipment
Last modified: 03/27/12