Valve Closure Timing, Electro-Hydraulic Control System
If you have the following. . . | Your pipeline BSDV must. . . | Your USV1 must. . . | Your USV2 must. . . | Your alternate isolation valve must. . . | Your surface-controlled SSSV must. . . | Your LP hydraulic system must. . . | Your HP hydraulic system must. . . |
(1) Process upset | Close within 45 seconds after sensor activation | [no requirements] | [no requirements] | [no requirements] | [no requirements]. | ||
(2) Pipeline PSHL | Close within 45 seconds after sensor activation | Close one or more valves within 2 minutes and 45 seconds after sensor activation. Close the designated USV1 within 20 minutes after sensor activation. | Close within 60 minutes after sensor activation. If you use a 60-minute manual resettable timer, you may continue to reset the time for closure up to a maximum of 24 hours total | [no requirements] | Initiate unrestricted bleed within 24 hours after sensor activation. | ||
(3) ESD/TSE (Platform) | Close within 45 seconds after ESD or sensor activation | Close within 5 minutes after ESD or sensor activation. If you use a 5-minute resettable timer, you may continue to reset the time for closure up to a maximum of 20 minutes total | Close within 20 minutes after ESD or sensor activation. | Close within 20 minutes after ESD or sensor activation. If you use a 20-minute manual resettable timer, you may continue to reset the time for closure up to a maximum of 60 minutes total | Initiate unrestricted bleed within 60 minutes after ESD or sensor activation. If you use a 60-minute manual resettable timer you must initiate unrestricted bleed within 24 hours | Initiate unrestricted bleed within 60 minutes after ESD or sensor activation. If you use a 60-minute manual resettable timer you must initiate unrestricted bleed within 24 hours. | |
(4) Subsea ESD (Platform) or BSDV TSE | Close within 45 seconds after ESD or sensor activation | Close one or more valves within 2 minutes and 45 seconds after ESD or sensor activation. Close all tree valves within 10 minutes after ESD or sensor activation | Close within 10 minutes after ESD or sensor activation | Initiate unrestricted bleed within 60 minutes after ESD or sensor activation | Initiate unrestricted bleed within 60 minutes after ESD or sensor activation. | ||
(5) Subsea ESD (MODU or other type of workover vessel, Dropped object) | [no requirements] | Initiate valve closure immediately. You may allow for closure of the tree valves immediately prior to closure of the surface-controlled SSSV if desired. | Initiate unrestricted bleed immediately | Initiate unrestricted bleed within 10 minutes after ESD activation. |
Valve Closure Timing, Electro-Hydraulic Control System With Loss of Communication
If you have the following. . . | Your pipeline BSDV must. . . | Your USV1 must. . . | Your USV2 must. . . | Your alternate isolation valve must. . . | Your surface-controlled SSSV must. . . | Your LP hydraulic system must. . . | Your HP hydraulic system must. . . |
(1) Process upset | Close within 45 seconds after sensor activation | [no requirements] | [no requirements] | [no requirements] | [no requirements]. | ||
(2) Pipeline PSHL | Close within 45 seconds after sensor activation | Initiate closure when LP hydraulic system is bled (close valves within 5 minutes after sensor activation). | Initiate closure when HP hydraulic system is bled (close within 24 hours after sensor activation) | Initiate unrestricted bleed immediately, concurrent with sensor activation | Initiate unrestricted bleed within 24 hours after sensor activation. | ||
(3) ESD/TSE (Platform) | Close within 45 seconds after ESD or sensor activation | Initiate closure when LP hydraulic system is bled (close valves within 20 minutes after ESD or sensor activation). | Initiate closure when HP hydraulic system is bled (close within 60 minutes after ESD or sensor activation) | Initiate unrestricted bleed concurrent with BSDV closure (bleed within 20 minutes after ESD or sensor activation) | Initiate unrestricted bleed within 60 minutes after ESD or sensor activation. | ||
(4) Subsea ESD (Platform) or BSDV TSE | Close within 45 seconds after ESD or sensor activation | Initiate closure when LP hydraulic system is bled (close valves within 5 minutes after ESD or sensor activation). | Initiate closure when HP hydraulic system is bled (close within 20 minutes after ESD or sensor activation) | Initiate unrestricted bleed immediately | Initiate unrestricted bleed immediately, allowing for surface-controlled SSSV closure. | ||
(5) Subsea ESD (MODU or other type of workover vessel), Dropped object | [no requirements] | Initiate closure immediately. You may allow for closure of the tree valves immediately prior to closure of the surface-controlled SSSV if desired. | Initiate unrestricted bleed immediately | Initiate unrestricted bleed immediately. |
30 C.F.R. §250.838