Line Freezing and Line Stops
Line freezing, or freeze plugging, is a non-intrusive method of isolating sections of pipe. With a boiling point of -320.4F, liquid nitrogen makes quick work of most line freezing jobs. The extreme cold forms an ice plug inside the pipe but it also temporarily narrows the pipe in the center, creating a slight hourglass shape that locks the plug in place. Due to the change in shape, line freezing creates a strong plug that has been shown to withstand upwards of 10,000PSI.
Most types of piping can be successfully frozen.
Line freezing has many advantages over mechanical line stopping, the first being no welding, sparks or contamination of the piping system with metal chips or particles. It is not a permanent modification to the piping system. This eliminates future potential leak points in fitment and heat affected zones. When we remove our freeze can equipment from the piping and allow the pipe to naturally thaw, there will be no sign the operation had ever occurred.
This procedure originated in Europe and was widely used in the nuclear industry. It had the advantage of not being a permanent modification to the piping system. This eliminated engineering costs, delays, design changes and volumes of procedural paperwork.
As the line freezing procedure became more widely used, the potential was realized. It quickly spread to the non nuclear world. Most of our large industrial customers do not have the luxury of taking an unplanned outage to replace one or a few random faulty mechanical components. Many times limited or no isolation is available. As demands have changed this business has spread to commercial, institutional and governmental facilities.
Services we regularly freeze are:
Fire Protection Water
Requirements to perform a line freeze are a “NO FLOW” condition; it can be blocked in 10’ away or in some cases miles away, but must be in an absolute “NO FLOW” condition. In the event of a leak in piping our On-line Leak Repair service can remedy the situation until the pipe freeze can be achieved.
Types of facilities that utilize line freezing services:
Multi Story Residential Buildings
Municipal Water Systems
Typical projects we have completed are: Freeze plugging all piping involved with relocating existing piping while installing a new elevator shaft in a major St. Louis Missouri hospital. This was a lengthy project. We routinely freeze fire protection lines in numerous power utilities, and service water and climate control piping in many office buildings. Econo Seal has assisted several mechanical contractors with this service as a complement to their maintenance contracts.