The water flow should be stopped completely. Often the Cold-Shot is used to replace a valve like this that isn't working properly. It is best to shot off the water flow at another location upstream to the repair location. Moving water is difficult to freeze. Call the Drain Brains at 800-245-6200 for more information.
Used this system in Vegas casinos a number of times, works as described.
What if the valves don’t hold properly and shut off about 80% will this method work?
The water flow must be stopped for the Cold-Shot to work best, just as the still water in a pond freezes over faster than a flowing river.
The water flow should be stopped completely. Often the Cold-Shot is used to replace a valve like this that isn't working properly. It is best to shot off the water flow at another location upstream to the repair location. Moving water is difficult to freeze. Call the Drain Brains at 800-245-6200 for more information.