time delay between SDV and BDV
time delay between SDV and BDV
(OP)
Dear Friends;
As you know in case of fire occurrence on platform; it is necessary to consider an appropriate time delay to ensure that Emergency shutdown valves(ESDVs) are closed before Blowdown valves are opened to prevent any problem like flare overloading.
I want to know how much the required time and what relevant criteria or standard for this matter is.
Is the time to be considered from time the ESDVs are being closed or it is considered after full closure of ESDVs.
Tnx
As you know in case of fire occurrence on platform; it is necessary to consider an appropriate time delay to ensure that Emergency shutdown valves(ESDVs) are closed before Blowdown valves are opened to prevent any problem like flare overloading.
I want to know how much the required time and what relevant criteria or standard for this matter is.
Is the time to be considered from time the ESDVs are being closed or it is considered after full closure of ESDVs.
Tnx





RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
Section 5.2.7- BDV timers:
In order to prevent flare overload, local BDV timers (pneumatic or hydraulic) shall be installed to ensure that ESDVs are closed before BDVs are opened.
RE: time delay between SDV and BDV
"Upon confirmed fire and/or gas detection, automatic emergency de-pressurisation (EDP) offshore, and optional onshore. Open all the BDVs (Blow-Down Valves) in the fire zone with a pre-set time delay (30 s to 1 min.). If de-pressurisation is not automatically initiated upon ESD-1/F and/or ESD-1/G, a push button located in the CCR initiates ESD-1/F and/or ESD-1/G and opens all BDVs with a pre-set time delay."
RE: time delay between SDV and BDV
Section 5.2.7- BDV timers(this section is subsection of 5.2 EDP requirements):
In order to prevent flare overload, local BDV timers (pneumatic or hydraulic) shall be installed to ensure that ESDVs are closed before BDVs are opened (short delays in the order of a few seconds and in the limits of rules set forth in section 7.1.2).
Such local timers shall be forbidden to achieve phased depressurisation (say, one minute or more). If such phasing is necessary, a proposal shall be submitted for COMPANY's approval indicating its justification and technical provisions selected to ensure that common mode
failures will not impair the flare/vent system integrity.
RE: time delay between SDV and BDV
RE: time delay between SDV and BDV
I'll still standby my opinion including implications on flare system overloads, If the risk of further problems in a locatione wher humans are versus overloading a flare system which is out of the way, I'd overload the flare. If TOTALS policy favors underloading a flare and allowing a backup that could cause failure in a populated area, thats their risk.
RE: time delay between SDV and BDV