MultiTherm FF-1®

Purpose 
MultiTherm FF-1® flushing fluid is for use in start-up or general maintenance of heat transfer fluid systems. During new e start-up, it is an economical way to remove loose material such as weld splatter, fines, particulate matter, etc. left in lines and e, along with oil and some preservative coatings. It is useful for general maintenance purposes for removing particulate matter and used heat transfer fluid from a system prior to recharge or changeover from one fluid to another.

MultiTherm FF-1® flushing fluid is formulated to be compatible with MultiTherm® and most other heat transfer fluids so that small residual amounts left in e will not be a problem.

System Preparation
New systems may contain mill scale, weld splatter, slag, flux, quench oil, protective coatings, dirt and water. The abrasive contamination can damage pump seals, bearings, and control valves. Mill scale and weld splatter can promote fluid oxidation and cracking. The oil, coatings and flux are thermally unstable and can cause fluid degradation.

Some say to leave the system as is, and explain that buying replacement fluid a little earlier is cheaper than the cost of cleanout. However, the cost of mechanical seal replacement and control valve rebuilds probably exceed the cleanout cost. When the expense of unscheduled downtime is added, the cost of professional cleanout is usually justified.

Removing mill scale, oil and coatings from all pipe sections and fittings before installation can avoid problems. Use Robvon or equal back-up rings at each weldment. Clean and dry out the heater and all heat users before installation.

It is strongly recommended that water not be used for cleanout of an assembled system or for “hydro” pressure testing. Water in a hot oil system will cause pump cavitation and can easily ruin pump seals and bearings. Trapped in a dead leg and hit by high-temperature fluid, water can literally blow up the pipe, or the expansion can push hot fluid from a vent, possibly jeopardizing personnel. To pressure test a system, use either MultiTherm FF-1® flushing fluid or heat transfer fluid or inert gas in lieu of water. Pressurize fluid with nitrogen, not air.