Wall thickness to dia. ratios for hydraulic hoses of unreinforced poly - for ease of mfr. and assembly of hose for 100 bar working pressures

摘要

Hydraulic hoses for working pressures =100 bar are made of unreinforced semi-rigid plastic material (specifically polyamide-11 or -12) having a tensile strength >500 kg/cm2. The hose profile has a ratio of wall thickness/mean dia. (i.e. 1/2 (external dia. +internal dia.)) of >=0.5, pref. 0.5-0.7. Hoses are esp. of 1.3-1.8 mm bore, 6-8 mm external dia. for use at a working pressure of 100 bar and a max. (test) pressure of 400 bar, e.g. vehicle brake system hoses. Hoses are simpler to make and/or install than hoses with braided and/or textile internal or external reinforcement or use of rigid tubes linked by numerous short reinforced flexible or angled couplings.