Self Operated Regs
What closes a self-operated regulator?
down stream pressure
What is the spring action of the main valve and pilot?
Pilot is spring to open and main valve is spring to close.
When selecting a relief valve, accuracy is defined by what criteria?
build up or pressure build up
In an unloading style pilot operated regulator what is the impact of losing the inlet line?
The main valve will go wide open.
Where must the wavy lines of a diaphragm go when installing it?
to the low pressure side of the regulator
What are the three essential elements of a regulator?
loading, measuring, restricting
How does a two path pilot operated regulator open?
The pilot senses the downstream pressure change and opens to load the loading chamber of the main valve.
What is the spring action of a self operated relief valve?
spring to close
In the monitor system, what happens when the worker fails?
The pressure increases and the monitor takes over.
What is the name for the pressure below the relief valve set point to close off the valve after it opens?
reseat pressure (reseat)
What are the three types of flow designs designs?
flow to close, flow to open, balanced trim
How does the size of the restriction impact how the regulator opens and closes?
larger restriction-opens slower and closes faster
smaller restriction- opens faster and closes slower
What three considerations are there for over pressure protection?
downstream equipment, low pressure side of the regulator, the pipeline MAOP
In any style regulator with an external control line, what happens in the event of a control line break?
The regulator will go wide-open.
What are two rules of thumb for selecting a regulator?
Always start with the lightest spring.
Use the smallest orifice that will provide the required flow.
What is bagging the diaphragm and why must we do it?
It is the process of stretching a new flat sheet diaphragm to ensure that we get the full valve travel for full flow of the regulator.
What is minimum differential pressure?
The minimum difference of (P1-P2) required to fully stroke the main valve open.
In a wide open down stream monitor, what regulator has the highest set point?
the monitor
In a loading style pilot operated regulator, using a pilot with combined bleed and sense line, what should happen when you close a valve in the control line providing everything is properly working?
The main valve should close.
Explain the process of setting up a wide-open monitor system.
1) Decrease the set point of the monitor.
2) Increase the set point of the worker (above the monitor).
3) Set monitor to desired set point.
4) Set worker to desired set point.
5) Test for lock-up.
If you find a small knick on an orifice, what can you do to temporarily fix the problem? What is an impact of doing so?
(must get both parts to receive credit)
You can sand it down using fine sand paper (Crocus Cloth) and it will have a higher lock up pressure.
What key feature makes a pilot-operated regulator more accurate than a self-operated regulator? What is the equation to determine it?
Gain
Gain=Change in PL/Change in P2
What are the rules to a working monitor?
First stage is always the monitor, first stage is always a pilot operated regulator with two pilots, 2nd stage is worker and can be self-operated or pilot operated.
What are some of the characteristics of a slam shut?
Name 3 of 4 minimum.
gas is not vented to atmosphere
high and low pressure shutoff capabilities
integrated and stand-alone options
requiring a service call to reset
Explain the process for setting up a WORKING MONITOR System.
1) Decrease the set point of the monitor.
2) Increase the set point of the worker (above the monitor).
3) Increase the set point of the intermediate pilot above monitor pilot set point.
3) Set monitor to desired set point.
4) Set worker to desired set point.
5) Set intermediate pilot.
5) Test for lock-up.