Hose

Introduction

Fire Hose is a flexible high pressure tube used by firefighters to carry water/foam under pressure from the source of supply to a point where it is discharged.

Hose is a flexible pipe used to convey water the source to the scene of fire.

1. Types of Hose:

    (a) Delivery Hose: This hose is used to transfer water from supply point to the destination at required pressure. This is connected to the discharge side of the pump. This is subjected to a pressure greater than the atmospheric pressure.

Material                 :         Polyester / Cotton / Flex / Rubber.

Working Pressure  :         Up to 14 Bar (200 PSI).

Size                      :         63 mm.

Length                   :         7.5 / 15 mtr.

i. Canvas Hose (Unlined hose): Made from Flax, Hemp, Cotton and other plans, outer two layers of woven fabric jackets (wrap thread and weft thread).

ii. Non Percolating / Rubber Hose (Rubber Lined hose): Same as above and rubber lining added (type A and type B hoses).

iii. Percolating Type: This is to ensure continuous oozing of water all around the jacket in a controlled manner without affecting pressure. This is used in places of high heat radiation.

    (b) Suction Hose: This hose is usually a rubber-covered, semi-rigid hose with internal metallic reinforcements. It is used to suck water out of unpressurized sources, such as ponds or rivers, by means of a vacuum. These are connected to the suction side of the pump. These are subjected to either above or below the atmospheric pressure.  These are of following types:

i.       Partially embedded are Rubber covered, Fabric and Wire (Helix), Reinforced, Rubber lined.

ii.     Smooth Bore fully embedded are Rubber covered, Fabric and Plastic (Helix), Reinforced, Rubber lined.

2. Characteristics of Hose

(a) Flexibility: Hose must be sufficiently flexible to,

–      Enable it to be handled with ease.

–      Enable it to be made up into a smooth and tight role.

(b) Durability:

• Hose must be a strong enough for it to be reliable during the use.
• The material used in its construction must have high resistance to abrasion and should be able to withstand the rough usage.
• A tough plastic outer cover will provide additional protection to the jacket and prolong its life.

   (c) Resistance to rot: Hoses are made up of natural fibers are prone to be affected by rot or fungi. Hoses must be anti-rotting agents such as Zinc Chloride, Penta Chloro Phenyl Laurate (PCPL).

3. Material used

          Weft                                         Wrap

          It resist burst                            Durability to resist wear and tear

Flax                                          Flax

Nylon                                       Flax

Terylene                                   Flax

Nylon                                       Cotton

Terylene                                   Cotton

Terylene                                   Terylene

4. Causes, Nature or Damage and Remedial Measures

5. Care and Maintenance of Hose

i. Store in a cool, dry and well-ventilated place.

ii. Hoses should be cleaned and dried periodically. 

iii. Rubber lined hoses should be cleaned by passing water through them and dried on towers, periodically. These should not be exposed to hot dry air or sun rays for long periods.

iv. Hoses should be stored in long folds or in figure eight position.

v. The folds should be changed periodically.

vi. Hoses contaminated with acids /alkalies or oil should be cleaned and dried before storing.

vii. Hoses should be drained by under running and not be walking over them.

6. Cleaning Procedure

i.    Normally the cleaning is done with water alone.

ii.   If the hose is contaminated with grease /oil then add a little soda in water and clean.

iii.  If the hose is contaminated with thick grease /acid /oil, use saw dust and fine sand to rub off the sticky substances.

7. Drying Procedure

i. Natural: In sheds constructed in such a way as to permit the entry of air as much possible. But no rain should enter it. The hoses are hung from towers or hooks at the roof of the shed with the help of pulleys.

                   ii. Mechanical: In chambers of brick construction. Provision is made to accommodate 20 lengths of hoses. All the hoses are coupled to manifold through which warm air is blown. An exhaust fan is fitted to the chamber so that constant air is circulated.

 

8. Repairs

          After use, the hose should be inspected carefully to detect the damage and to repair the same for future use. Every damage such as pin holes should be marked, and the defective hoses should be rolled with male coupling inside for the sake of identification.

i.           Hose covering & Bandages: Leather gaiters and canvas bandages are applied where the hose appears to be weakened.

ii.     Darning: Pin holes are generally repaired by darning some strands of flex. A patch should be placed on the same.

iii. Patching: Leaks in the hose are satisfactorily repaired by patching.