Vessel Closure Lock

Access into pressure vessels is a potentially hazardous exercise. Residual pressure, volumes of residual liquids or gases can be harmful.  Typical examples of potential hazards include pig traps, slug catchers and filter housings.

Locking the vessel closure in the closed position ensures access into the vessel takes place, under controlled-safe conditions. The operating key is held in a secure place e.g. Control Room or Supervisor’s office or is retained (trapped) in some other related interlocked item of equipment. Most international vessel design codes, as a minimum, require vessel closures to be interlocked with venting and draining functions.  This interlocking arrangement can be extended to incorporate all other vessel functions (e.g. draining, purging or flushing).

DL3 2
Locking Arm Engaged                                                                          Locking Arm Released

The SFC ‘DL3′ interlock is adaptable to all types of vessel/access closures and is very simple to use in pig trap applications, especially where the closure incorporates a bleed device. The ‘DL3′ interlock will be designed to interface with the bleed function, to ensure the bleed screw cannot be removed until the interlock permit key has been inserted to unlock the ‘DL3′ assembly. This key is usually obtained after opening and locking of the vent valve. When the ‘DL3′ is incorporated into vessel access safety procedures, total equipment and personnel safety is assured.

vessel closures closed and open
Locked                                                                                                            Open – Key Trapped