Q. What if the pipe to be frozen has no means by which to make the flow static. What would be the benefit of your service?
A. There are two answers to this question. First if the system has to be shut down to establish an ice plug and remain down, then the time to drain and refill the system is saved, plus the aggravation of purging the air from the system. Second, in many cases where the line frozen is a branch connection the system only has to be off long enough to establish the ice plug and then the system may go back online while the work is performed.
Q. Can you freeze a pipe with flow?
A. Yes and No. The flow in a pipe should be static for ideal conditions. This is not always the case. Leaking pump seals, packing around valves, even cracked expansion joints have been successfully frozen. Liquid Nitrogen lets us put temperatures of 325 below zero to the pipe. This process overcomes leaks (small flow) where CO2 procedures will not.
Q. How long does it take to establish an ice plug?
A. This varies with size, start temperature, and the type of liquid to be frozen. One of the most common applications is a cooling water or chilled water system. An example of this would be an eight inch pipe size starting at fifty five degrees Fahrenheit takes approximately forty minutes to freeze.
Q. Can you freeze glycol (anti-freeze) or systems containing glycol?
A. Yes, glycol simply lowers the freezing point. Many chemical treatments change the freezing point. This is one of the reasons that we have a multi-check procedure to determine when an ice plug has been successfully established. To date the largest line we have established an ice plug in was a 24" pipe with 25% glycol mix.
Q. Can a freeze be done over a weld or damaged piping?
A. It can; however it is not an ideal condition. Waters Mechanical will inspect any weld which would become part of the ice plug and determine if it's a sound weld we would feel comfortable covering with a freeze jacket. Safety being one of our highest priorities we reserve the right to refuse to freeze over welds or damaged piping.
Q. Will the freeze process create enough pressure to break or crack my pipes?
A. It can, however Waters Mechanical utilizes temporary pressure relief systems which allow the pressure to be relieved as the ice plug forms.
Q. How much pressure can an ice plug (freeze seal) hold?
A. In our facility we have set up test specimens and held hydrostatic pressures of 1,800 PSI in a 10" inch std. wt. steel pipe for over an hour with no change. Waters Mechanical has not exceeded the stated test pressure ourselves; however we have researched this question and found that given the ice plug is long enough the pipe will fail before the plug lets go.