Calibration Hoses & Fittings The Ralston Hose and Fittings system comprises, wire wound 6900 psi hoses with connectors that require no tools by using leak-proof 'O' ring seals. A unique feature of the system are the adapters for industry standard fittings such as Swagelock, Gyrolock and Tylock. The system also includes adapters for common pressure transmitter bleed ports from Foxboro, Honeywell, Rosemount and Yokogawa.