1" Bypass around Large Bore Valves
1" Bypass around Large Bore Valves
(OP)
We have several P&ID's for a project that call for 1" bypass piping around large bore valves (6", 12", 14" NPS). These are not control valves, they are just regular hand and gear operated block valves.
I'm just curious what purpose or situations call for a 1" bypass around large bore valves?
If the question is too vague or more information is needed, just let me know.
Thanks
I'm just curious what purpose or situations call for a 1" bypass around large bore valves?
If the question is too vague or more information is needed, just let me know.
Thanks





RE: 1" Bypass around Large Bore Valves
RE: 1" Bypass around Large Bore Valves
RE: 1" Bypass around Large Bore Valves
Very dependant on how often you need to shut and equalise pressure and the sensitivity of your valves to opening under pressure.
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RE: 1" Bypass around Large Bore Valves
RE: 1" Bypass around Large Bore Valves
Think about a sliding gate valve. If the valve is closed and pressure on both sides of the gate are equal, the valve is easy to open because the equalized pressure allows the gate to be centered within its housing and seal assembly. The pressure on both sides could be 1 psi or 10,000 psi- the valve does not really care, as long as the pressure is in balance.
Take that same sliding gate valve, and apply 10,000 psi to one side and 1 psi to the other- you have 9,999 psi of pressure driving the gate valve against the low pressure side of the housing, creating a potentially HUGE friction force holding the valve in place, making it very difficult to open.
In this case, you would open the ball valve in the bypass and allow pressure to equalize on either side of the gate, making it possible to open the gate valve with much less force.
RE: 1" Bypass around Large Bore Valves
RE: 1" Bypass around Large Bore Valves
RE: 1" Bypass around Large Bore Valves
MJCronin
Sr. Process Engineer
RE: 1" Bypass around Large Bore Valves