Steam Trap Options 

Thermic Vent Buckets

Whenever steam is turned on and off, air will accumulate in the piping and steam equipment. A trap equipped with a thermic bucket will discharge this air 50 to 100 times faster than a standard bucket, reducing warm-up time. Thermic vent buckets are suitable for pressures to 130 psig (9 bar). A large vent hole in the bucket can also solve air-venting problems upon start-up.

Internal Check Valves 1/2" (15 mm) thru 2" (50 mm) NPT

Almost all Armstrong inverted bucket steam traps can be equipped with internal check valves. A check valve is needed between the trap and the equipment being drained in the following cases:

  • When the trap is installed above the unit drained
  • When sudden pressure drops may occur in the steam supply
  • Whenever back pressure exists in the condensate return line

Armstrong spring-loaded, stainless steel internal check valves can be screwed directly into the trap inlet or into an extended inlet tube having a pipe coupling at the top.:

In-Line Check Valve 1/2"(15 mm) and 3/4" (20 mm) NPT

On 1800 and 2000 Series stainless steel traps, an internal check valve cannot be installed. Armstrong CVI “in-line check valve will solve the problem.

Pop Drain for Freeze Protection

In general, a properly selected and installed Armstrong trap will not freeze as long as steam is coming to the trap. If the steam supply is shut off, a pop drain should be used to drain the trap automatically.

Maximum Operating Conditions

Pressure: 600 psig (41 bar)

Temperature: 350°F (177°C)

Vacuum Breaker 3/8" (10 mm) and 1/2" (15 mm) NPT

A vacuum will often cause condensate to be retained ahead of a steam trap. To break a vacuum, air must be introduced into the system by means of a vacuum breaker.

For maximum protection against freezing and water hammer in heating coils under modulated control, for example, vacuum breakers are recommended in conjunction with freeze-protection devices.

Dirt Problems

Whenever dirt plugs the bucket vent, Armstrong recommends the use of a scrubbing wire to clear the hole on each cycle. Note: On small stainless steel (only) bucket traps, a wiggle wire is installed as standard.

In normal conditions, the inverted bucket trap is not sensitive to dirt problems (because of its orifice at the top of the trap), unlike most other traps, which should be installed with a strainer. (See Armstrong Y-Type Strainers.)

Probe Connections

Probe connections are available for trap monitoring on most inverted bucket traps. Consult your Armstrong Representative for details.


Now you can insulate the in-line traps in your plant without complicating regular trap maintenance. Insu-Pak, a simple reusable insulation package, cuts the time and cost of in-field installation because it goes on in a snap. And it comes off just as easily. The Insu-Pak can prevent trap freeze-up when used with a properly designed condensate manifold. Designed for use with Model 2010 and Model 2011 traps.