Composite Pressure Vessels

We fabricated and pressure tested three toughened composite pressure vessels using very high strength steel (500 KSI strength) wire screen with a steel cable over-wrap in an epoxy matrix. In testing, the pressure tests attained two thirds of its calculated burst pressure of 1650 PSI and the diametric expansion at 1000 PSI was recorded to be 0.032 inches (0.5%) which is well within the acceptable limits. These pressure vessels were nearly cylindrical 6” nominal diameter, 18” long, 0.19” thick  and were fabricated using five layers of high tensile 16x13 mesh wire screen cores with a 3” overlapping joint. The pressure vessel cores were injection molded using a modified acrylic/epoxy resin.  The ends of the first of these vessels were then sealed with 3” long stainless steel plugs adhesively bonded with epoxy. We believe that this technology could also easily be extended to include fabrication of flexible high-pressure vessels by using a high elongation urethane or rubber-like elastomer as the matrix.

a                                               b                                                     c

(a) A pressure cylinder as processed after resin transfer molding (RTM),

(b) with a circumferential wrap of cable and end inserts placed for testing and

(c) cylinder in a hydraulic test fixture with dial gauge indicators.