The Purpose Of The Branch Is To Increase The Velocity Of Water And May Be Defined As "A Metal Fittings Between Hose And The Nozzle That Converts Pressure Energy Into Velocity Energy To Provide The Nozzle A Solid Jet-Of Water For Fire Fighting."
A) HAND CONTROLLED:
Hand Controlled Branch:
Also known as "London Branch", has devices either to shut off, alter to spray,
or to get jet or deliver jet and spray simultaneously. Each function is capable of
independent control. This branch has the following metal parts.
● Main Body
● Semi Circular handle
● Hexagonal base
● Nozzle
● Flange
● Jet valve
● Inner cylindrical, tube Rotating collar
By turning the rotating collar anti clockwise direction, the spray can be varied from a cone of 300 to a flat sheet of 1800. But the size of the jet is not adjustable and depends on the size of nozzle 16 mm or 19 mm. It can be maximum 22 mm because the 1 D of the branch would not permit.
● This branch can give spray or jet of variable size which can be shut off as may be required.
● The spray could be varied from an intense mist over an angle of 180 to a complete shut off.
Its parts are:
● Man body,
● Adjustable rotating sleeve,
● Mushroom shaped deflector.
● This branch can be adjusted to give a water stream for straight jet, a fine or coarse spray and complete shut off.
● The fine spray is in the form of mist or fog, thus the name.
● A floating rotary valve connected with the handle facilitates the control operations.
● To prevent the entry of any foreign material wire mesh is provided in a cylindrical tube in between the rotary valve and the male instantaneous coupling so that the holes of the spray nozzle or spray head, are not blocked.
● The spray head is detachable and held in position by the spring loaded interlocking arrangement.
● With this-type of hand-controlled branch, the spray head or spray nozzle can be extended with extension piece or low-pressure applicator can be connected to fight small oil fires or discharge the fog directly to the burning surface.
The Size of the jet is normally 16 mm.