"Pipe Freezing is used for temporary isolation by creating a solid ice plug inside the pipeline. This is considered the safest, most economical and effective method for allowing general pipework modifications, maintenance and valve change out etc.
Pipe Freezing can be performed on a variety of pipe materials such as:
Pipeline fluids that have been crystallized to form an ice plug include Freshwater, Glycol solutions, Seawater, Effluents / Sewage, Produced water, Sludge’s, contaminated water, Crude oil, Fuel oils, Lubrication oils, various chemical products."