Title of Invention	A LIQUEFIED PETROLEUM GAS RUBBER HOSE
Abstract	This inventon relates a liquefied petroleum gas rubber hose used as a connection between the stove and LPG cylinder characterised in that it comprises a three-layer hose comprising an outer layer (A) of extruded Nitrile/PVC blend or a reinforcement (B) wire braiding, and an inner lining (C) of nitrile or equivalent rubber compound extrusion.

Full Text

This invention relates to a liquefied petroleum gas rubber hose used as a connection between the stove and cylinder of an LPG installation. Presently, a rubber tubing is used as the connecting flow means between the rubber and the regulator of an LPG instal-lation. A cause of the majority of accidents are due to the failure of rubber tubing. As recognized in the art, the connection between the stove and the regulator of the cylinder is the only . flexible part which leads to leakage and hence to accidents. The maj or reasons for the failure of the present rubber tubing are as follows : 1. The material of the tubing is not resistant to LPG; 2. As the tubing is flexible and without any reinforcement, it is prone for attack by rodents and other sharp edged contacts; 3. The tubing is not resistant to fire and atmospheric degradation and hence initiation of cracks due to prolonged exposure to atmosphere particularly with Ozone and oxygen and also catches fire and opens out when exposed to a small flame. An object of this invention is to propose an improved construction of a liquefied petroleum gas hose. Another object of this invention is to propose a liquefied petroleum gas hose which obviates the disadvantages associated with those of the prior art. Still another object of this invention is to propose a liquefied petroleum gas hose which is fire-resistant and atmospheric degradation-resistant. Thus according to the present invention, there is provided a liquefied petroleum gas rubber hose used as a connection between the stove and LPG cylinder characterised in that it comprises a three-layer hose comprising an outer layer (A) of thick neoprene rubber compound wrapping, a middle layer of reinforcement (B) wire braiding, and an inner lining (C) of nitrile rubber compound extrusion. Further objects and advantages of this invention will be more apparent from the ensuing description made with the non-limiting embodiment of the accompanying drawings where Fig.1 shows a cut-away view of the three section hose pipe. A sectional view of a typical hose pipe shows the following A is an outer core comprising a neoprene rubber compound wrapping, B is a wire braiding with a braid angle of 130 and comprising a 4 strand wire, and C is the inner lining made of nitrile rubber compound extrusion. The hose of the present invention comprises of the following three major parts 1. Inner lining, 2. Briaded reinforcement, 3. Outer cover, where the inner lining is constructed from a nitrile compound, the braided reinforcement from a low tensile mild steel wire and the outer cover is made of neoprene compound. The rubber hose of the invention has a nominal bore, ie. inner diameter of 7.9 _+ 0.5 mm, outer diameter of 15.7 _+ 0.5 mm, an inner lining thickness of 2.5 _+ 0.2 mm, a reinforcement thickness of 0.3 jf 0.05 mm, an outer cover thickness of 1.0 +_ 0.2 mm and a wall thickness of 4.1 +_ 0.5 mm. In accordance with this invention, the inner lining is extruded out of a rubber compound made out of nitrile rubber and compounded for resistance to hydrocarbons and shall not be more than 70 IRHD hardness. The cured compound shall be soft enough to facilitate easy insertion of the hose to the nozzles and to improve the grip strength of the hose to the nozzle. The inner lining is covered by the MS wire braiding at a braid angle with strands of wire so as to cover the length of the tubing uniformly. The outer cover of the hose is wrapped around the braided reinforcement with a rubber compound made of polychloro-prene. This compound is compounded for resistance to fire and atmospheric degradation by weathering (including Ozone), and fire-resistance. Both the compounds comprising the inner and the outer lining have to be compounded for better adhesion towards the reinforcement. The hose is so constructed that it can withstand the following working/test conditions : Maximum working pressure : 17.0 Kgf/cm 2 Test pressure : 25.35 Kgf/cm 2 Minimum burst pressure : 52.0 Kgf/cm Minimum bend radius : 89.0 mm The outer cover of hose is preferably green in colour. The hose of the invention meets the requirements specified in BS:3212, Clause-9. The hoses are to be supplied in cut lengths of 1.25 mtrs. each and the ends of the cut hoses shall be smooth without any wires protruding out of the ends. The invention described hereinabove is in relation to a non- limitirig embodiment and as clarified by the accompanying claims. WE CLAIM: 1 . A liquefied petroleum gas rubber hose used as a connection between the stove and LPG cylinder characterised in that it comprises a three-layer hose comprising an outer layer (A) of thick neoprene rubber compound wrapping, a middle layer of reinforcement (B) wire braiding, and an inner lining (C) of nitrile rubber compound extrusion. 2. The hose as claimed in claim 1 wherein said outer cover is compounded for resistance to atmospheric weathering and fire. 3. The hose as claimed in claim 1 wherein the thickness of said outer cover ranges between 0.8 mm to 1.2 mm. 4. The hose as claimed in claim 1 wherein the inner lining is covered by a MS wire braiding having a broad angle 130 and a 4 strand wire. 5. The hose as claimed in claim 1 wherein the thickness of said wire braiding varies between 0.25 mm and 0.35 mm. 6. The hose as claimed in claim 1 wherein the inner lining is compounded to be resistant to hydrocarbons. 7. The hose as claimed in claim 1 wherein said inner lining has a thickness varying between 2.3 mm and 2.7 mm. 8. A liquefied petroleum gas rubber hose substantially as herein described.

Documents:

0031-mas-1996 abstract granted.pdf

0031-mas-1996 claims granted.pdf

0031-mas-1996 descripiton(complete) gratned.pdf

0031-mas-1996 drawings granted.pdf

31-mas-1996-claims .pdf

31-mas-1996-correspondance others.pdf

31-mas-1996-correspondance po.pdf

31-mas-1996-description complete.pdf

31-mas-1996-form 1.pdf

31-mas-1996-form 5.pdf