From Wikipedia, the free encyclopedia

A hydrant wrench is a tool used to remove fire hydrant caps and open the valve of the hydrant. They are usually adjustable so as to fit different sized hydrant nuts.

Several tricoise wrenches; the red ones at the top are in the vehicles, the yellow in the middle hang at the fire belts, the bottom one is a polycoise

In France, the hose and hydrants are linked with Guillemin symmetrical clutch (raccord symétrique Guillemin), which requires the rotation of 1/4 turn of a ring to be fastened. The ring is notched.

The wrench is called "Guillemin wrench" (clef Guillemin, /kle gijəm~ε/), but the firefighters call it "tricoise wrench" (clef tricoise, /kle trikwaz/). The curved part applies on the ring, and the hooked part clutches a notch.

Big tricoise wrenches are placed in fire trucks, and are mainly used to fasten the big hoses, e.g. ∅110 mm hoses to feed the pumper tank from the hydrant (∅100 mm for the clutch). Small tricoise are made of brass and hang at the fire belts; they are used to fasten the small hoses, e.g. ∅70mm to ∅22mm hoses (∅65mm to ∅20mm clutches).

The shape is sometimes adapted so it can be used as a tool for other purposes; it is then called "polycoise wrench" ou "Deschamps wrench". These tools are used to

• 12mm female triangle wrench: opening the gas and electricity standard boxes of EDF-GDF
• 15.6mm female triangle: opening the boxes of the fire hydrants;
• 5×5mm to 8×8mm square female wrenches: opening the doors without knob, the ventilation acceses and the closets containing firefighting equipment in some public locations;
• 12.5×12.5mm square female wrench: open the dry risers;
• screwdriver: opening the bathroom and toilet doors;
• unfastening nuts with the 13, 17 and 19mm six-point wrenches.

Drawing of a United States hydrant wrench.

The head of a hydrant wrench.

The shape of a hydrant wrench is sometimes adapted so it can be used as a tool for other purposes such as:

• Storz and spanner hose couplings
• Rocker lug couplings
• Water meter shutoff valves
• Gas cock valves
• Pentagonal nuts
• Square nuts.