Canvas Hose Pipe - Application: Modern

The hose shall ,be constructed from a circular woven jacket having a waterproof rubber lining or rubberized fabric lining on the inside, facing the waterway and with or without Elastoplast- meric coating/covering (Type A) and with Elastoplast coating/covering (Type B). The jacket shall be seamless and compactly woven from good quality cotton yarn or from yarn made from suitable synthetic fibre of polyamide or polyester type of good quality or from their combinations. Fire hose with outer coating/ covering shall be manufactured using synthetic yarn only. Inner lining shall either be of rubber 3r rubberized fabric and shall be generally smooth and practically free from pittmg and other imperfections. having arrangement to *bleed out entrapped air with the help of suitable stop cock or pet cock. Fill the hose with lvater and raise the pressure to 70 kPa ( 0.7 kgf/cm ). Allow all air to escape through stop cock by raising the free end of the hose and again rebuild the pressure to 70 kPa. Sow kink the hose through 180 at approxi- mately 50 cm from the free end by tying the hose back against itself as close to the fitting as practi- cable. Increase the pressure at a rate not exceed- ing 1 MPa ( 10.2 kgf/cm2 ) per minute to 2.1 MPa ( 2 I.4 kgf/c& ). When maximum pressure has been attained, retain it for 30 seconds, re- lease the pressure, examine it for sign of leakage and damage. There shall be no sign of leakage or rupture and no thread in the jacket shall break Hydrostatic Burst Pressure Test - A test length of hose, one metre clear of fittings when subjected to an internal hydraulic pressure in accordance with 8.2 of IS : 443-1975*, in- creasing it at the rate not exceeding 1 MPa ( 10.2 kgf/cm ) per minute shall not burst or show leakage before a pressure of 3.5 MPa ( 35.7 kgf/ cm2 ) is reached. A test piece measuring 1 metre in length shall be marked around the circumference at a distance of 60 mm from each end. The test piece shall be kept immersed in an oil bath for 70 hours containing oil No. 3 specified in 1 S : 3490 ( Part 6 )-1983* and maintained at 50 f 2C in such a manner that the both ends are so clamped that the marks are in level with the surface of oil and the remaining entire length of the test piece within the marks remains comple- tely immersed in oil. At the end of this period, the test piece shall be taken out in such a manner that the portions beyond the marks do not come in contact with the oil. The length shall be laid horizontally and the central fully immersed por- tion of the hose shall be visually examined for any swelling ofrubber, weathering and cracking in the rubber lining. Test pieces taken from the central ( fully immersed ) portion of the hose shall then be subJected to an adhesion test in accordance with the method described in Appendix B and shall meet the requirements as given in 5.11.1 (for both lining and cover ).