When it comes to tube expansion, there are two main types of lubricants: liquid lubricant and paste lubricant. Liquid lubricant is a semi-fluid, clear synthetic liquid, with deionized water and without sulfur, chlorine, or metallic salts. Paste lubricant is a smooth, water-soluble paste that can be used in an undiluted or diluted state. While some operators have personal preferences with what type of lubricant they use, there are a few industry recommendations and standards to consider.
Liquid lubricant is often used on stainless steel or titanium tubes due to its low sulfur content. It is also commonly used in the electronic and nuclear industries. Paste lubricant on the other hand, is commonly used in air coolers or other applications where the operator is reaching through the header box, as it doesn’t drip into the vessel. When using paste lubricant for copper and brass tubing, it is recommended to dilute the paste. Paste lubricant is also used when the operator wants to put lubrication in the tube prior to rolling.
Both lubricants prolong tooling by keeping the tube expander cool and preventing debris from adhering to the expander’s mandrel and rolls. A cooler cleaner tool will extend tool life by as much as 2 times.