ISO 6808 pdf download.Plastics hoses and hose assemblies for suction and low-pressure discharge of petroleum liquids — Specification
1 Scope
This International Standard specifies the requirements for two types of polymer-reinforced thermoplastics hose and hose assembly for suction and discharge applications with kerosene, heating oil, diesel fuel and lubricating oils in the temperature range – 1 0 °C to + 45 °C. NOTE The hoses can be stored in a static condition at – 30 °C to + 65 °C without damage by climatic conditions.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 3:1 973, Preferred numbers — Series of preferred numbers. ISO 1 76:1 976, Plastics — Determination of loss of plasticizers — Activated carbon method. ISO 1 88:1 998, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests. ISO 471 :1 995, Rubber — Temperatures, humidities and times for conditioning and testing. ISO 527-3:1 995, Plastics — Determination of tensile properties — Part 3: Test conditions for films and sheets . ISO 868:1 985, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore hardness). ISO 1 307:1 992, Rubber and plastics hoses for general-purpose industrial applications — Bore diameters and tolerances, and tolerances on length.ISO 1 402:1 994, Rubber and plastics hoses and hose assemblies — Hydrostatic testing. ISO 1 746:1 998, Rubber or plastics hoses and tubing — Bending tests. ISO 1 81 7:1 999, Rubber, vulcanized — Determination of the effect of liquids. ISO 4672:1 997, Rubber and plastics hoses — Sub-ambient temperature flexibility tests. ISO 7233:1 991 , Rubber and plastics hoses and hose assemblies — Determination of suction resistance. ISO 7751 :1 991 , Rubber and plastics hoses and hose assemblies — Ratios of proof and burst pressure to design working pressure. ISO 8031 :1 993, Rubber and plastic hoses and hose assemblies — Determination of electrical resistance.
4 Construction and materials
The hoses shall be as uniform as commercially practicable in colour, opacity and other physical properties. Flexible thermoplastics materials shall be supported inside the material by a helix of polymeric material of a similar molecular structure. The reinforcing and flexible components of the wall shall be fused and free from visible cracks, porosity, foreign inclusions or other defects causing the hose to be unserviceable. Hose assemblies shall be electrically bonded between couplings. Electrical continuity may be ensured by an antistatic strip welded along the hose on its outer surface. The antistatic strip may consist of a braided copper wire coated with suitable plastics material and shall be anchored to the metal couplings in a manner that will ensure reliable electrical continuity throughout the life of the hose. The method of ensuring initial electrical continuity shall be the responsibility of the manufacturer and shall be carried out to the satisfaction of the user.
5 Dimensions and tolerances
5.1 Diameter The nominal bore of the hose and the internal diameter and tolerances shall be in accordance with the values given in Tables 1 and 2, which are in accordance with ISO 1 307.
6 Physical properties of finished hoses
6.1 Hydrostatic requirements at standard laboratory temperature When tested at standard laboratory temperature as specified in ISO 471 by the method specified in ISO 1 402, the hose shall meet the requirements given in Table 4. When examined at proof pressure (i.e. 50 % of minimum bursting pressure), the hose shall show no evidence of leakage, cracking, abrupt distortion or electrical-continuity damage.