Pig Trap Door Interlock

Pig Launcher / Receiver Interlocks

Interlock Description

The Alcatraz closure door lock is designed to interlock the closure door of a pigging vessel. The closure lock prevents the bleed plug from being removed, this means it prevents the closure door from being opened. Only the insertion of a dedicated key releases access to the bleed bolt, so it can be removed. This key is only released after the door is closed and the bleed plug is back in its place. The Alcatraz closure lock is suitable for all types, sizes and different manufactures of closure doors.

During the pig launching and receiving procedure, the operating written procedures must be followed carefully by the operators. If the vessel is not drained and vented, or when the isolation valves are not fully closed before opening the closure door, extremely dangerous situations can transpire. The Alcatraz Interlocks closure lock (CL), as a part of an interlocking sequence, prevents these hazardous situations. By guaranteeing and safeguarding that the isolation valves are closed and the vessel is vented and drained before the closure door can be unlocked and opened.

Types of door locks available

CL: closure lock

Interlock dimensions

Depending on brand, size and type of the closure door.

Lock features

  • Solid and compact construction with a minimum of moving parts.
  • Material: stainless steel AISI 316, electro polished.
  • Our key will survive a drop of more than 25 meters according to the drop weight impact test, ASTM E208.
  • Easy and smooth operation, also with industrial gloves.
  • Transferable lock portions.
  • Fire safe in accordance with the API 607 sixth edition test.
  • Tested on functioning in low temperatures.
  • Resistant against sand, dirt and moisture.
  • Easy to install, even when the valve is in a live process.
  • Maintenance free, no grease necessary.
  • Tamperproof.
  • Automatic closing AISI 316 protection caps on keyholes with text plate as standard.
  • Ergonomic key position.
  • As an option the integration of electronic components such as limit and proximity switches are available.