Once a hydraulic swivel has been designed, reviewed and machined, the housing and spool are moved to the clean room and all parts are pulled to make a complete assembly. Then the housing and spool are moved to the assembly machine. Here the spool is pushed into the housing using an air over oil system. The operator manually turns a crank which extends the cylinder rod and slowly advances the spool into the housing, while monitoring the pressure from a gauge until the spool is fully inserted. Doing this operation manually allows the operator to physically feel if there is any binding occurring, which may cause internal damage to the seals, housing and/or spool. The rest of the assembly is completed and the swivel is then placed into our production machine for torque and pressure tests.
Each swivel is prefilled with hydraulic fluid and rotated in both directions while the torque is monitored by load cells. Then the pressure of each circuit is tested at 1.5x the operating pressure, up to a maximum 7500 psi. The pressure is monitored by two pressure transducers, one for even and one for odd circuits. The cleanliness of the oil is continually monitored by an ICM at the 17/15/12 level, thus ensuring we keep the internal circuits of each swivel at a high cleanliness level. The torque, pressure and oil cleanliness are all stored and saved as a birth certificate for each swivel. The fluid in the swivel is then reclaimed back to our oil reservoir. Next, the swivel is removed and all ports are plugged and prepared for primer or primer and paint. Each one is individually banded to a crate, ready for shipping to each client.
Every step in the process provides the client with confidence that each swivel has been put together with the utmost care and will perform to expectations.
For more information on hydraulic swivel production testing, visit our blog.
Thomas Van Veldhuizen