From the little detail you provide I assume you are referring to the Condensate extraction pump vents.
These must return to the condenser from high points to ensure line is liquid filled and causes minimum pressure loss to the pumps. NPSH available to CEP is very small and must all be used if full capacity is to be obtained.
Leaving valve open is not a problem provided both halves of condenser are in use.
Mainly oil extraction, fishing and logging.
A derrick is a rig, typically associated with the drilling for and extraction of oil or natural gas.
Mainly to persuade others or your audience.
the sole purpose of compression sports wear is mainly for protection and if it is cold, WARMTH.
water receives heat to become vapour thus carrying energy . water is mainly used because it is plentiful and has very high latent heat of vapourisation which absorbs a hell lot of heat during evaporation. here heat energy is converted into pressure energy during heating formation of steam and then expanded in turbines or let out to get kinetic energy as the output.
Mainly from Africa, from the tusks of elephants killed for that purpose.
It's mainly used as a disinfectant and preservative.
I think it was mainly to carry the ten commandments in.
my guess is to mainly get more information.
Adipose tissue is just fat tissue. It's purpose is mainly to add protection to your body.
it is used mainly for keyboard and display function
It takes care of mainly unimportant district issues.