Lagging in steam traps

In India/Pakistan/UAE/Saudia Arabia & other hot areas/countries you do not need to lag steam traps. These are required only in very cold areas/countries say like Canada/USA/Russia etc where there is extreme far below 0C temperatures that steam traps may freeze and fail to operate , thermostatic or any other types.

You do have a good knowledge. Put a Steam Trap photo on your avtar.

The one and the only "Spirax Man". Ask C. Ball, if he's still around ;-)

Correction one more. not only. 8 years Spirax Man

Insulation covered with, usually a metal shield, causes condensation and creates the problem you are concerned about.

I have worked on many systems and Steam Traps and Pigtails are bare, all ancillary piping and vessels can be lagged or insulated.

Think wearing extremely heavy clothes in a sauna.

All steam traps require heat to be radiated to ensure proper function or they could steam (vapor) lock and the trap will not be able to flow the stated capacity.

The only time a steam trap should be lagged/insulated is in instances where they pose a safety/burn hazard.

If the trap needs to be insulated, then the distance between the trap inlet and the main line or process should be extended to accommodate condensate backing up.

Regardless of where you are located in the world, unless your ambient air temperatures exceed 212 deg F, optimal insulation thickness for pipe should be used to reduce:

1. Fuel source consumption (natural gas, heating oil, etc)

2. Reduce CO2 emissions

3. Reduce water used

The above savings are achieved through reduced radiant heat loss to ambient temperatures.

If you are looking to insulate your steam system, I would focus on:

1. Storage tanks

2. Heat Exchangers

3. DA Tanks

4. Boilers

5. Steam distribution pipe

6. Condensate return pipe

7. Condensate return pumps

8. Moisture separators

9. Control valves

10. Regulators

A great resource to determine optimum insulation/lagging is:

http://www.pipeinsulation.org/

If you are fortunate enough to be located in California, the local gas utility companies are offering $3.00 per linear ft rebate to insulate steam & condensate pipes.

Best regards to all!

It is not true that all steam traps need to radiate heat. Venturi steam traps, having a fixed opening, will not "vapor lock" (actually the result of a vacuum being formed when the steam valve is closed, the mechanical trap is closed, and the trapped steam condenses thereby taking up a tiny percentage of the volume that the steam had.) This is why Air Handlers, using mechanical traps, add a vacuum breaker.

Insu-Pak™

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.

Courtesy Armstrong international

In areas where a steam trap could freeze, the following things need to be done:

1. Do not use bucket traps, as it is impossible to get all of the water out of the units due to them requiring a water seal to ensure the trap will close at the presence of steam (all bucket traps required this -it's usually referred to as the "prime").

2. Freeze protect the traps that do not require a prime by adding a liquid expansion trap to the drain port of the trap. The liquid expansion trap fill is designed to make the trap open and drain out the water in the trap when the condensate temperature drops to at least 35 deg F (above the freezing point).

No insulation will prevent a steam trap from freezing if the steam is no longer flowing to the trap. Your only recourse is to be VERY careful on the trap type used, and install the trap so that all of the water in the trap drains out under near freezing conditions to prevent the condensate in the trap from freezing & cracking the trap wide open.

The following is an excellent link on freeze protection hook-up:

http://www.spiraxsarco.com/resources/cad/applications/steam-trapping/preview/steam-mains-drainage.asp?drawing_id=72

Excellent. You deserve a vote.

Your question is what is Lagging? It means thermal insulation.

<...LAGGING...> is also there to provide thermal protection to persons. If protection can be achieved in other ways, such as by segregation of the hot surface from persons, then <...LAGGING...> might not be necessary.