Shut Down Valve

**rotanimod** · 12-31-2008, 03:54 AM

Hi. I am a process/operation engineer. I post this thread to find answers from instrument guys regarding installation philosophy on SDV. Recently, I've been designing a new gas injection line. Since our well will no longer produce oil, we planned to rigged down the 2" gas lift line and reuse the available SDV for the new gas injection line. This gas injection line however, will accommodate much higher gas flow at higher pressure, thus was sized as 3" line. Therefore, reducers will be fitted in order to install the reused SDV. Through some calculations, the gas velocity through the line and SDV is acceptable. My concern then will be: is it technically acceptable to configured SDV with reducers? I've been through many P&IDs and noticed that usually SDVs were installed directly with the line without any blockage/reducers. Are there any design standards that prohibit such configuration?? Thanks.

**sphere2004** · 12-31-2008, 11:34 AM

There are no code/guidlines that prohibit use of reducers /expanders as far as I know of.

**sri2cool4u** · 01-01-2009, 03:05 AM

Yes as our frnd said there is no specific regulation, but any how have a look at SHELL DEP which might give u some idea

But it actually matters on what the SDV is going to act, if it is based on the pressure in the line, it might not be right to fix it with reducers as it may not solve the purpose

**rotanimod** · 01-02-2009, 02:48 AM

"But it actually matters on what the SDV is going to act, if it is based on the pressure in the line, it might not be right to fix it with reducers as it may not solve the purpose"

Can u please explain more on above quote??

**karthiknew2008** · 01-06-2009, 11:15 PM

As a Such to my Exp, there is no philosophy for Shut Down Valves to include using Reducers ,

SDV's are basically for ISOLATION of the PLant under Critical or Abnormal situations . SO U put REDUCERS, WHat not, just see whether you are ISOLATING the line pressure < Design Pressure of the Downstream with Simulation of PIPESIM/ PIPENET .

SDV has only two modes , ON/OFF , so depending on the Signal ur Valve Solenoid makes the contact NC/NO to stop the FLOW.