A) SHORT BRANCH:
● It is only 8" (20cm) in length. It consists of a solid brass casting.
● The approximate weight is 2 kgs for the threaded type and 1.64 for instantaneous type.
STREAM SOLID BRANCH
● It is similar to the short branch in outward appearance but internally is fitted throughout its whole length with a
● cylindrical center tube open at both ends and of 1.25" diameter, held in position by three longitudinal guide vanes. The advantage is that it gives a more solid jet.
● Theory is that speed of flow of water in hose is greater in the center than at the boundary where there is friction, with the wall of the hose.
● As the cross-section area of the central tube does net reduce, the velocity of that part of water which travels through the center tube must be the same at the end as at the beginning.
● The velocity of the slower moving water in contact with the walls of the hose is greatly increased in the branch owing to its tapering shape and on reaching the nozzle, actually travels faster than the water leaving the central tube.
● Thus, the jet is composed of a control core held together by faster moving outer sheath water which tends to drag the core along with it giving a solid jet of water.
TWIN BRANCH
This is a relatively longer branch which bifurcates at the lower end, each leg terminating in a coupling for attachment to a line of delivery hose, thus being fed by twin lines of hoses; with this branch it is possible to get
jets at larger velocities and greater quantities of water. These are useful in collapsing buildings in dangerous condition
● A typical branch for dealing with fires involving coal heaps, hay stacks etc.
● It consists of 63 mm dia 10 feet long steel pipes with a pointed head having a number of 1/8" holes on it.
● The other end has a thread on which may be screwed either a collar containing a standard hose coupling or another 10 feet (3 mm) section of piping to extend, the branch still farther.
● A driving head may also be screwed on its head to enable the branch to be driven into the stack or bunker after which the head is withdrawn and the coupling screwed on. So that the hose can be connected.
A) REVOLVING BRANCH:
● This is a gun metal fitting having 63 mm male instantaneous coupling at the lower end and a revolving round head supported on ball bearing on both sides with cylindrical cap and nut on top.
● The revolving round head having the appearance of a dome is pursued with 9 holes of 6.35 mm diameter.
● Each hole has gone through a conical shape of 3.12 cm length, three on the circumference of the plane of revolution but inclined 600 to the tangent of the circular revolving plane, three in the Centre of the upper half pointing upwards at 600 to the vertical.
● These are used in places such as ships hold and basements. It is compact enough to be lowered down through ship ventilators or through holes made in the roof floors of the basements.
● This consists of a large gun metal casting made in two parts.
● The upper part comprises a collecting breeching to the outlet of which is connected casting which revolves on ball bearing and carries four equidistant outlet.
● Two of these are in the form of branches diametrically opposed and fitted with standard nozzles.
● The other two also located opposite to each other are inclined to the diameter.
● It is rotated by the back pressure of water passing through two outlets inclined to the casting.
● This also is used to fight fires in ships holds / basements.
This is a piece of equipment for use at smoky fires in basements of ships. It is fitted with nozzle which can be made to elevate, depress and rotate by remote control. Total length is 4 ft 6 inches and can be folded when not in use.
These are used for generating foam. One end has a male coupling. The construction is so designed that air is drawn in due to the increase in velocity of the foam compound passing through the nozzle and creating a vacuum.
These are mounted on vehicles or fitted on Fire Hydrants which can handle large amounts of water. Single person can operate them.
● The nozzle is a small metal fitting made of gun metal or brass or bronze having a tapered shape generally.
● But it can be made to several shapes depending on the nature of purpose it is manufactured for.
● These have female thread (internal thread) for attachment to the branch.
● As a precaution against damage the delivery orifice is counter sunk in the nozzle to a depth of 3 mm.
● The base of the nozzle is hexagonally shaped to permit the use of spanner.
● Standard nozzles to fit any branch with 63 mm or 70 mm hose are made of machined gun metal and vary in length from 4 to 4V2".The bores of the nozzle vary in diameter from 4.6 mm to 44 mm.
● Larger bores are used in Deluge sets or Monitors etc.
● Besides there are nozzles used for Hose Reel Hose, Portable Extinguishers.
● Also, there are nozzles made suitable for providing fine mist or combination of spray etc.
COLLECTING HEADS
● It consists of a metal casting of aluminum or gun metal fitting with two, three, four or six inlets for Delivery Hose and a single Female Suction Coupling for attaching to the suction inlet of a pump.
● Each of the inlets is provided with a non-return valve which consists of a metal casing and screwed into the body of the collecting head and fashioned to a male instantaneous coupling.
● The valve is mushroom shaped with either a synthetic rubber or a metal ground face and is held against a seating by means of spiral spring.
● The water pressure forces the valve off its seating preventing the escape of water, getting fast stuck to its seating. The valve lift must not be less than 16 mm.
● These fittings are primarily used in closed relay when they are fitted to the intermediate and delivery pumps.
● It is used in-case of collector pumping to augment the water supply to a pump from weak pressure fed sources.
● It may help in priming a pump with a defective Primer. It may serve the purpose of Blank cap while the pump works from a mounted tank.
● It may also be used at the end of suction hose to avoid repeated priming in case thepump needs to be stopped from time to time.
● This consists of a metal suction strainer fitted with an extension tube in the casting between the strainer proper and the coupling.
● In this extension, a flap - type reflux valve is fitted in such a manner that, water rising up into the suction forces it open.
● If the pump is stopped the flow ceases immediately in the suction, the flap valve falls back on its seating, thus preventing the water from escaping and keeping the suction fully changed.
● This avoids re-priming of the pump when it is to be started again.
DEEP LIFT SUCCTION FITTING
● It consists of a light alloy body incorporating an inlet strainer plate and housing a two-stage ejector unit.
● The inlet connection is 63 mm instantaneous male and outlet depends on the application.
● When used for Fire Services it usually has 102 mm diameter oudet. Two eyes are provided for attaching the lowering ropes.
● It takes delivery of high pressure water from the normal fire pump and transfers the energy to a, large volume of water at lower head.
● Lifts up to 80 feet are possible with this fitting.