- Key Features
Freeze it and make your Pipe Repair Easy!
Accu-Freeze™, the controlled liquid nitrogen (LN2) pipe freezing system is a method to freeze stationary liquids in a selected section of a pipe or tubing. It is the World's only patented, digitally controlled pipe freezing system thus allowing you to accurately and safety create an ice plug.
By controlling the surface temperature of the pipe, Accu-Freeze™ can safely and accurately form an in-line ice plug, capable of withstanding 138 bar (2000 Psi) in pipes up to 12" (300 mm diameter).
The Major Advantages of Accu-Freeze™
The Accu-Freeze™ temporary plug isolates the section of pipe or tube, allowing repairs or modifications to be made without shutting off or draining the entire system.
The major advantages of an Accu-Freeze™ System are:
- Saves valuable time normally lost draining and refilling a system.
- Avoids complete shutdown of systems and equipment.
- Prevents waste of large amounts of water.
- Eliminates handling of contaminated water.
- Is safe and cost effective.
- Can be controlled from a remote location.
- LN2 delivery system is notably colder than other refrigerants.
- Standard products to suit pipe and tube sizes up to 12" (300 mm).
- Capability of automatically controlling the freeze temperature.
- Has a LN2 delivery, which is more cost effective than other refrigeration systems.
Accu-Freeze™ Key Features
The ice plug only forms beneath the Accu-Freeze™ coil wrap, jacket or aluminium clam jacket which is used on a 6 - 12" (150 to 300 mm) pipe or tube and does not expand outside of the range of jacket or coil.
An ice plug is formed by wrapping copper tubing or specially designed insulated jacket around the section of pipe to be frozen. The LN2 is then injected through the patented control system.
The water or other liquid in the pipe or tube needs to be in a static condition (no flow). The Accu-Freeze™ wrap is placed around the pipe up stream from the section to be repaired.
Accu-Freeze™ takes over by automatically injecting the LN2 to a temperature set by the user through the system over the in-line ice plug. Once the plug is formed, maintenance and repair can take place without draining or shutting off the entire system.
Each unit can be set to 220 V or 110 V and a working scale of oC or oF.
Optional aluminium jackets are available.
Freeze Pipes up to 12" (300 mm)
The Accu-Freeze™ System is available with a coil wrap, jacket or aluminium clam jacket, which is used on a 6 to 12" (150 to 300 mm).
The design of the jacket incorporates adjustable straps, which will allow the user to alter the jacket size according to the application requirements.
The controlled freeze process safely creates the ice plug without affecting the integrity of the pipe. (Pipe bursts happen when the ice forms in an uncontrolled manner and creates hydrostatic pressure between ice plugs or against a closure in the line). Detailed user instructions are provided to help the end user select an appropriate location to safely freeze the line.
In the nuclear industry there are also restrictions regarding exposure of certain pipes to cryogenic temperatures. Accu-Freeze™ makes it possible to create an ice plug while keeping the pipe wall temperature within the allowable temperature limits.
Frequently Asked Questions
1.0. What applications is Accu-Freeze™ designed for?
Accu-Freeze™ utilises liquid nitrogen to create the cryogenic temperature necessary to form ice plugs. Freeze sealing is most often used to isolate a section of a piping system where no other ready means of isolation (such as valving) is available. Freeze sealing refers to the process of applying an external refrigerant to a point in a process in order to cause the formation of a solid internal plug from the frozen process fluid contained in the pipe.
2.0. What size pipes is Accu-Freeze™ suitable for?
The Accu-Freeze® insulating jacket accommodates pipe sizes from 6 - 12" (150 - 305 mm).
Copper coil is used for the smaller sizes.
Aluminium clam shells are available for 2” - 16” (50 mm - 400 mm).
3.0. Is ventilation required?
LN2 is heavier than air and will displace oxygen. Sufficient ventiliation is required, especially when operating in confined areas.
4.0. What protective clothing should be worn when operating the Accu-Freeze™ System?
Protective clothing i.e. gloves, goggles etc. must be worn at all times when operating the Accu-Freeze™ System.
5.0. Can I freeze on a weld?
It is not ideal to freeze on a weld unless the weld has been x-rayed.
6.0 Can I freeze contents that are moving within a pipe?
No, the liquid contents of the pipe have to be stationery and non-vibrating
7. 0 Can I freeze liquids other than water?
Yes, milk, beer are all examples of other liquids that can be frozen. Some liquids containing refrigerants can be frozen too, just check with our Technical Team on the type and % content.
8. 0 Can I do a freeze either side of the repair joint?
Yes, this is called a double freeze and necessary accessories can be purchased along with the Accu-Freeze™ kit. A double freeze is required when a valve needs replacing for example.
9.0 What kind of pipes can Accu-Freeze™ be used on?
Accu-Freeze™ can be used on iron, lead, steel and copper pipes. It is also applicable to plastic pipes, but these will take up to three times longer.
10. What about bursting or fracturing pipes?
Pipe fractures are not caused by the ice plug or the freezing process. They are caused by a failure to allow enough space between the ice plug and closed connections. This is due to the increase in pressure that is caused by water that is displaced by the ice plug as it grows that can create a ‘hydraulic ram’ if enough space is not allowed.
11. What if there is a small amount of glycol or other fluid in the line?
It is important to know how much is in the mix and what the freeze point of the liquid is. Note: the ‘freeze point’ may just be a slush and not to the solid state that is required for a plug.
Shipping Information, Weights and Dimensions
European Customs Tariff: 9032 10 80
International Customs Tariff: 9032 10 8090
United States Customs Tariff: 9032 10 8990
Canada Customs Tariff: 9032 10 8990
Product Codes and Sizes:
HFT Pipestoppers® Accu-Freeze™ Pipe Freezing Systems are supplied as a complete controlled liquid Nitrogen system.
Note CO2 is not included.
Please see the the tables below for the contents of the full system as well as the Cryogenic Freeze Seal Jackets and all the accessories.
Delivery on the all items is 7 to 10 days.
HFT Pipestoppers® Accu-Freeze™ Pipe Freezing Systems
Accu-Freeze™ Liquid Nitrogen Pipe Freezing System up to 12" containing:
|AF2000-HV||Control Solenoid Valve Header Complete High Flow|
|Solenoid Valve Only|
|Manual Isolation Valves|
|AF3000||Digital Controller Complete|
|AF4010||10ft. Flexible Cryogenic Hose|
|AF4020||20ft. Flexible Cryogenic Hose|
|AF4025||25ft. Flexible Cryogenic Hose|
|AF4030||30ft. Flexible Cryogenic Hose|
|AF4400||Ferrules, Fittings, Tee Connectors Asst'd Pack|
|AF5001||Type "T" Connector Plug (Male) 10 pack|
|AF5002||Type "T" Connector Jack (Female) 10 pack|
|AF5004||T/C Wire @ 4ft. with Male End Connector|
|AF5033||T/C Wire @ 33ft. with Male & Female Connector|
|AF5100||Thermo Couple Wire 100ft. Roll|
|AF7050||50 Litre LN Dewar w/ PB Liquid Discharge (22 psi OP)|
|AF8000||2 Channel Temp Monitor Battery Operated|
|AF9000||6 to 12" (150 to 300 mm) Insulating Jacket|
Accu-freeze™ crypgenic freeze seal jackets
Items available as 'Downloads'
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HFT Pipestoppers® Accu-Freeze™ User Instructions Technical Manual
HFT Pipestoppers® Accu-Freeze™ User List Customer Reference
HFT Pipestoppers® Accu-Freeze™ User List Material Safety Data Sheet MSDS
HFT Pipestoppers® Accu-Freeze™ Price List