Twin Ferrule & Coned and Threaded Connection Differences

Twin ferrule mechanical grip fittings are considered a low pressure fitting, working up to around 10,000PSI. Anything working at above these pressures are considered medium and high pressure fittings, because of the higher pressures involved, the tubing wall is greater than that of low pressure tube, this means the twin ferrule connection method, can not work on the tubing in these ranges, as the tube wall is too thick to allow the ferrules to swage correctly onto the tubing.

• Low Pressure ; up to 10,000PSI
• Medium pressure ; up to 20,000PSI
• High pressure ; up to 60,000PSI

For medium and high pressure tubing the connection method changes from twin ferrule mechanical grip fittings to the more robust method of male coned end on the tube that has an interference fit with a female concave cone on the component the tube is to join, with the aid of a collar and gland and the correct torque make up, theses fittings can work to pressures well beyond the twin ferrule connection.