Drain header

[sps24]

All;

I am trying to design a closed drain header that will eventually tie to my closed drain system. Some of the drains include level transmitter drains. Typically how much flow should I assume from these instruments to size the line? Currently I am thinking of 2" line which ties to a 4" header

Any help will be appreciated.

Regards,
sps

 

[RaRo]

For the level transmitter drains: those are normally just purges (opened when one need to maintain the instrument), a 1/2 to 1 line inch is enough. You have to consider what mechanical resistance you want. If operating/mtn people can (physically, even if not allowed) use your pipe as a footstool, you'd be better off with 1" as a minimum line diameter. If you are working with dirty/cristallizing liquid, 1" may well be too tight for proper cleaning, and 2" would be more adequate.

Since the flow from those will be intermittent and gravity is the motor force, you only need for the header the minimum line size you decided upon for any drain.

If other drains connect to that header, consider the sum of those at a decent velocity, and take the larger diameter between that and your minimum pipe diameter.