Freeze Protection

Steps to Prevent Freezing

When steam lines and devices are located in outdoor freezing environments, they are prone to becoming frozen themselves whenever the steam is shut down for any reason. If the installation is flawed, lines, exchangers or traps can be lost to freeze damage even when there is steam pressure to the system. There are a number of freeze protection steps you can take when installing steam systems in these environments.

 

 

• Do not oversize the steam trap.
• Install a vacuum breaker integral to the trap or in the drip leg. This prevents condensate retention when the steam pressure in the heat exchanger attempts to modulate below atmospheric pressure.
• Keep trap discharge lines as short as possible.
• Be sure there are no low points that are not drained in the system.
• Pitch trap discharge lines down for gravity drainage.
• Insulate all supply, discharge and return lines. Note that insulation of steam trap in a non-freezing environment may interfere with the function of the trap.
• Consider tracing any exposed return lines.
• Often, for the sake of maintenance, installations use overhead mains with long drips to a ground-level trap that discharges to an overhead return. On such installations, insulate the drip leg and discharge line together. If the return is pressurized, place a check valve at the top of the discharge riser. Connect a manual valve to the bottom of the drip leg. This valve serves to empty the drip leg when the trap is open for cleaning or repair.Install manual or automatic valves at other low points to drain the system when steam is shut off.