Hydraulic fluids are designed to have an extremely low freezing point and a high boiling point. To repair a hydraulic line or pipe, sometimes it is necessary to freeze a small portion on the line to create a plug. The freezing point of hydraulic fluid is around -70 F; however, under pressure the freezing point is much lower. To safely freeze a plug you must attach a freeze clamp and run liquid nitrogen through the line for the entire job.
Things You'll Need
- Freeze clamp kit
- Liquid nitrogen
Record the diameter and the PSI rating of the line that you are going to freeze.
Contact a company that sells a pipe freeze kit, or freeze clamp kit. Let them know the diameter of the line and the pressure that hydraulic fluid is held at. The size of the pipe and the pressure of the line will determine the size of the liquid nitrogen tank needed, and how long the fluid will take to freeze a solid plug.
Attach the freeze clamp to the pipe. Open the gas vent on the freeze clamp. Attach the hose to the clamp and the liquid nitrogen tank. Completely open the valve of the nitrogen tank.
Wait the appropriate amount of time for the plug to completely freeze. Small lines can be frozen in less than an hour; larger lines may take several days to completely freeze. When the allotted time has passed, cut a small vent on the side of the line you will be working on before making any large cuts.
Turn off the liquid nitrogen after completing the work on the line. Let the pipe thaw at room temperature until the frost melts off the clamp. After the clamp defrosts at room temperature, remove the clamp.
- Photo Credit Jupiterimages/Photos.com/Getty Images