FAQ

Here you will find our frequently asked questions. If you don't find the answer to your question, please feel free to contact us.

Does Cryostop International Pipe Freeze Seal offer pipe plugging procedures and training programs outside of the USA?
Most all CRYOSTOP™ Pipe Freeze technicians are equipped with valid passports. Our Pipe Freeze Service Dept. routinely receives international inquiries and have been contracted to perform projects internationally. We also offer CRYOSTOP™ Pipe Freeze Training programs for our international clients. Typical CRYOSTOP™ Pipe Freeze Training programs are custom tailored and are normally performed with the customer’s actual Pipe Freeze projects. Please contact us for your international training location.

So why won't Cryostop International's process cause an expansion break?
CRYOSTOP International doesn't freeze plug up against a dead-end and if necessary we install pressure relief equipment to monitor and control the internal pressure of the fluid.

Its just a chunk of ice. Why won't it blow out when we cut the pipe?
First, ice has an amazingly high adhesion to steel (you've witnessed that if you've ever tried to chip ice from steel surfaces in the winter). This, combined with friction of the long ice plug inside the irregular surface of the pipe would be enough to assure the plug isn't going anywhere. Additionally, Cryostop™ freeze plugs lock themselves in place due to a phenomenon known as "hour-glassing". As the Cryostop™ freeze plug begins forming, the pipe cylinder being chilled temporarily elastically reduces in diameter at a localized area inside our equipment. The Cryostop™ freeze plug then conforms to this shape, having large ends on either side of a narrower middle. This dimensional change of the pipe is small and only lasts as long as Cryostop International maintains the Cryostop™ freeze plug. It is one of the reasons why Cryostop™ freeze plugs can be used to hold back thousands of pounds of line pressure.

Don't the extremely cold temperatures cause damage to my pipe or alter it in some bad way metallurgically?
No. In fact there are types of steel that are "heat treated" to improve their performance properties by cryogenically quenching them. Extensive strain gauge, metallurgical and mechanical measurement studies by independent laboratories have shown that no permanent damage or deformation occurs with Cryostop™ freeze plugging.

How much pressure will the Cryostop™ freeze plugs hold?
Our standard “off the shelf” CRYOSTOP® Pipe Freeze Chambers are designed and engineered to provide safe and dependable Pipe Freeze Plugs up to 2000psi. However, depending on service temperatures and fluid types we do have engineered CRYOSTOP® Pipe Freeze Chambers designed for use on pipeline fluids up to 5000psi.

If this is so safe, why won't CRYOSTOP International freeze plugs over a joint weld or simple dent?
Cryostop International is a safety-driven company. We know that Cryostop™ freeze plugs are a well engineered procedure with large safety factors built into it. We don't want to use up any safety factor unnecessarily. Welds, dents, gouges, scrapes, corrosion pits and the like often hide dangerously weakened spots in pipe -- these are the spots where leaks occur. That's why CRYOSTOP International's pre-job inspection of your pipe is so important. We will work with customers that absolutely must Cryostop™ freeze plug over a welded joint or known defect, but it won't be easy and the customer should consider a mechanical line stop offered by our sister company, MTITAPS.

What is "Heat Convection" and how does it effect the integrity of the Freeze Seal Plug?
Heat Convection creates a convective flow of the internal fluid resulting in a heat transfer that may prevent or greatly slow the Freeze Seal Plug formation. Please see the document link "Effects of Heat Convection on a Freeze Seal".

What aspect of Cryostop™ freeze plugging makes pipe defects a concern?
Although Cryostop™ freeze plugs may temporarily increase the tensile and yield strength of your pipe by as much as 100%, the pipe is quite brittle inside the Cryostop™ freeze chamber during the procedure. If your pipe is damaged enough so that it's just about to fail at room temperature, while its being worked on there is an unknown degree of hazard.

So what are the mechanical hazards?
Impact, water hammer, pounding on or jerking the pipe around at the Cryostop™ freeze plug location. Again, these are not quantifiable hazards but it is obvious that temporarily super-cooled pipe shouldn't be abused with impacting stresses. This is why CRYOSTOP International insists on things like: (a) locating the Cryostop™ freeze chambers back away from your work location; (b) absolute securing of the pipe if its going to be opened or cut, and; (c) if feasible separate bell holes for the Cryostop™ freeze plugs and your work site if the job is on underground piping.

Why such an involved job procedure and rigorous safety monitoring?
It's that safety-driven Cryostop International philosophy again. Perfect execution of a job equals perfect and safe results. Cryostop International knows the hazards of handling cryogenic liquefied refrigerants and we take prudent precautions to assure a safe jobsite. That's why we insist on such a large safety perimeter on a jobsite. We're concerned about your safety too.

What are the Cryostop Pipe Freeze Seal Plug geographical service boundaries within the USA?
We dispatch our Freeze Seal Experts from strategic locations to perform Pipe Freeze Seal Plug Procedures in locations such as New York City, New Jersey, Chicago, St. Louis, Atlanta, Florida, Hawaii, California, Puerto Rico, Aruba, Trinidad and the Caribbean Islands.

Water pipes which have been exposed to extreme cold temperatures resulting in freeze plugs have been known to fail “burst”. Is it the cryogenic effect on the piping material that is actually responsible for such a pipe failure?
NO! When water freezes within piping it develops an internal freeze plug which grows outward in both directions of the pipe ID. If this outward freeze plug growth is allowed to form against a short dead headed section of water piping, it will create an enormous buildup of water pressure, which can eventually cause the strongest of pipes to burst.