Posted by Joesteam on June 05, 2001 at 05:21:55:
In Reply to: Main Steam Valve posted by Richard on June 04, 2001 at 10:26:23:
If the main steam valve is a non-return valve on a multi-boiler system, it is sized on the flow rate of the steam, so you may find it smaller than the boiler outlet piping.
If it is just a shut-off valve, it may also be the steam flow rate or someone trying to save a buck on the installation.