Coupling Procedure

The following is the procedure for coupling thermoplastic urethane or rubber lined fire hose using expansion ring couplings. This is the standard procedure unless the particular tender or order specifies other requirements.

Installation of standard couplings:

  • Extend the cylinder so that it will not rotate.

  • Thread the drawbar into cylinder and tighten with an Allen key.

  • Retract the cylinder approximately half way so that segment assembly can be screwed in.

  • Adjust the collar and pressure for the appropriate couplings.

  • Install the correct size segment assembly on the hydraulic expansion machine and adjust the stop collar to allow correct placement of the coupling.

  • Trim the ends of the hose squarely and visually check for lining delamination. If delamination is apparent, then trim the hose back until the liner is well adhered.

  • Retract the drawbar completely and adjust the hydraulic pressure to the required pressure for the coupling being installed.

  • Insert the brass ring over the expansion segments.

  • Insert the hose into the coupling bowl insuring that the hose is butted tightly against the backup washer. The male coupling should be installed on the end that is at the inside of the hose coil.

  • Place the hose and coupling over the segments until the stop is reached making sure that the hose does not slip back in the coupling bowl. Hold the hose and coupling assembly firmly in one hand and retract the drawbar until the preset pressure is reached. Release the pressure, turn the coupling 1/4 turn and re-pressurize.

  • Remove the hose and visually check to see that the expansion ring is properly seated and that the backup washer is still in place.

NOTE: Large diameter segments require removal of slotted cylinder adapter.

IMPORTANT: Always be sure to handle new hose with clean hands. If oil or grease gets on your hands, wipe it off.

Standard method of adjustment for the hydraulic expander (standard couplings):

  • Remove both the face and tail gaskets from the female coupling.

  • Put the coupling on the expansion unit and retract the drawbar slowly until the segments are open in the bowl, past the waterway.

  • With the segments in this position, pull the coupling up against the segments and screw the adjustment plate to the coupling leaving approximately 1/16” play.

  • Release the drawbar, remove the coupling, and insert the gaskets. The machine is now adjusted.

    EXCEPTIONS
    In Niedner products there are 3 exceptions in the types of segment assemblies used to couple XL-800™. These are 1 1/2”, 2 1/2”, and 3” x 2 1/2” (38 mm, 64 mm and 76 x 64 mm). The maximum expansion of a standard segment assembly is insufficient to properly seat the expansion ring against the tail gasket, hose and coupling bowl.

    Due to our thin walled hose products having larger ID’s than for which the segments were designed, the 1 1/2” (38 mm)XL-800™ can be coupled two ways. The first method is to couple the hose using 1 1/2” (38 mm) segment assembly and then re-pressurizing with a 1 3/4” (44 mm) segment assembly. The second method is to first enlarge the 1 1/2” (38 mm) rings so that the hose can be coupled with the 1 3/4” (44 mm) segment assembly.

    The 2 1/2” and 3” x 2 1/2” (64 and 76 x 64 mm) couplings require modified segment assemblies. These units are available on request.

Backup Washers 
Due to Niedner’s thin walled XL-800™ hose, a special thin walled double jacket tail gasket is required. If these special gaskets are not requested when ordering the couplings, the standard double jacket gaskets, for rubber lined hose, will be supplied with the couplings.

If the standard backup washers, for rubber-lined hose, are used to couple Thermoplastic Urethane (T.P.U.) lined hose, a proper seal is virtually impossible to achieve. The thicker gasket will take the brunt of the expansion and not allow a proper seal or retention to occur. The thin walled double jacket tail gaskets for Niedner XL-800™ are available on request.

Installation of Storz couplings
When ordering Storz couplings, it must be specified that the couplings are for Niedner SUPPLYLINE™. The shank size varies depending on the inside diameter of the hose. Since Niedner SUPPLYLINE™ has a larger inside diameter than Snap-Tite rubber covered hose, it therefore requires a larger shank.

Installation of Storz couplings:

  • Place the coupling in a vice or similar clamp so that both hands are free to work.

  • Trim the hose squarely and place it over the shank of the coupling. If the hose fits a little tight on the shank, you can use a liquid soap on the shank. DO NOT use oil or petroleum jelly.

  • Once the hose is correctly fitted over the shank, install the collars and screw in the bolts loosely (approximately 2 turns). Be sure to use a little oil on the bolts to avoid cross threading.

  • Tighten the bolts evenly, while at the same time, and use a flat screwdriver to push down any hose that might be pinched in the collar. If you are using a torque wrench, the requirements are approximately 42 pounds torque. Be sure to note that it is not necessary for the collars to touch at full torque.

    IMPORTANT:
    Always be sure to handle new hose with clean hands. If oil or grease gets on your hands, wipe it off. Due to the use of oil on the bolts of the Storz couplings, a plastic bag should be used to cover the coupling after assembly.

RECOMMENDED COUPLING PRESSURES

Single Jacket (Aluminum) Double Jacket (Aluminum)
SizePressureSizePressure
1”
(25 mm)
450 psi
(3150 kPa)
1 1/2”
(38 mm)
800 psi
(5600 kPa)
1 1/2”
(38 mm)
800 psi
(5600 kPa)
1 3/4”
(45 mm)
800 psi
(5600 kPa)
1 3/4”
(45 mm)
800 psi
(5600 kPa)
2”
(51 mm)
1000 psi
(6900 kPa)
2”
(51 mm)
900 psi
(6300 kPa)
2 1/2”
(64 mm)
1300 psi
(9000 kPa)
2 1/2”
(64 mm)
1000 psi
(6900 kPa)
3”
(76 mm)
1800 psi
(12400 kPa)
3"
(76 mm)
1500 psi
(10350 kPa)
4”
(102 mm)
2000 psi
(13750 kPa)
4”
(102 mm)
1800 - 2000 psi
(12400 - 13750 kPa)
5”
(127 mm)
2000 psi
(13750 kPa)
5”
(127 mm)
2000 psi
(13750 kPa)
   

 

Single Jacket (Brass) Double Jacket (Brass)
SizePressureSizePressure
1 1/2”
(38 mm)
350 - 400 psi
(2450 - 2800 kPa)
1 1/2”
(38 mm)
700 psi
(4900 kPa)
1 3/4”
(45 mm)
700 psi
(4900 kPa)
1 3/4”
(45 mm)
700 psi
(4900 kPa)
2 1/2”
(64 mm)
800 - 900 psi
(5600 - 6300 kPa)
2 1/2”
(64 mm)
900 psi
(6300 kPa)
3”
(76 mm)
1500 psi
(10350 kPa)
3”
(76 mm)
1500 psi
(10350 kPa)
    4”
(102 mm)
1800 psi
(12400 kPa)

 

Forestry ¼-Turn Quick Connection
SizePressure
1”
(25 mm)
450 psi
(3150 kPa)
1 1/2”
(38 mm)
450 psi
(3150 kPa)
1 1/2” UL
(38 mm)
600 psi
(4200 kPa)
Pumpkin Center Volunteer Fire Department


At Pumpkin Center VFD, we strive to give our members quality equipment to use at all times. We’ve found over the years that small details make huge differences. Our equipment committee is always asking the question “Is something better out there?” We stay abreast of current industry trends and investigate the latest and greatest from equipment manufacturers to make sure our guys and girls have what they need to do the job and do it well. In 2009 we were tired of the fire hose we had been purchasing and bought some Niedner XL-800. The hose is still in service today. During this time we’ve found that in addition to being durable, it rolls up extremely tightly, packs tightly in hose beds and is lightweight, which lessens fatigue on members. With a comparable friction loss rate to much other hose in the industry, our committee has yet to find a reason to leave Niedner. We had several sections of cloth Niedner 4 inch supply hose before switching to 5 inch as well. It was the best supply hose I’ve ever seen or used.

 

Casey Snyder, Assistant Chief, Pumpkin Center Volunteer Fire Department