Drying a Tube After Hydrotesting

use foam pigs and air to push water out. Then purge with dry nitrogen.

You can also pull a deep vacuum, 28.5+ in Hg would get the H2O out.

How about if I don't want to use pigs

^ blow a lot of air through the pipe

Hot air works better than cold air.

What do you think that is better if I want to dry the pipeline without pigs?

If I run only super dry air without pigs will I need to use more pressure so the pipeline can get completly dry or it does not matter?

Could you send me any link where I can read about pipeline drying?

Thanks

If you don't use pigs (even simple foam ones) it could take months to dry.

Just google it.

http://www.michell.co.uk/documents/en/pip/pipeline_drying.pdf

I tried that page but it doesn't explain me too much about time to dry. That even doesn't say that I need to use pigs.

thanks

time to dry is function of water left in and humidity of the drying agent. Do you material balance. If you use 100% humity air to blow through the line, the time required will be infinity. If you dry the air to bone dry, then every cubic 1 million cubic feet of air can pick up 30 pounds of water at 100% mass transfer rate.

This is enough google other sites, google "foam pigs" research research.....

Some years ago we needed to put a 500MW watertube boiler (2100 t/hr) into long term storage, after hydro and before operation. It was a coal fired boiler for power generation. The only confident means was using an arrangement of dehumidifiers connected to the water/steam circuit to attain a specified level of humidity prior to charging with nitrogen and maintaining a positive pressure. This was successful for a period of approx 6 years storage.

Hmmmmmmmm?

My question from the beginning of this posting is, if we are going to put water in the tubes of a water tube boiler why do we need to dry them out? Why not just flush them out with demineralized water?

What has "Guest" not told us?