Quarter turn valve interlocks

Alcatraz integral quarter turn valve locks fit on all type of lever operated valves / quarter turn valves.

Quarter turn valve interlocks

Interlock description

Alcatraz integral quarter turn (DQL/SQL) valve locks fits on all type of lever operated valves/quarter turn valves such as ball valves, plug valves, 3-way ball valves, butterfly valves and even instrument valves. They are mounted on 90° rotating valves to interlock the locked open and/or locked closed position of the valve. Only if both keys are inserted in the lock portions the valve can be operated. The first key can only be released in the fully open position, the other key can only be released in the fully closed position.

Typical applications include changeover valves (ball), pressure safety relief valves, loading and unloading of pig traps and sampling devices. Also 180°and 270° rotation are possible as an option.

General arrangement drawing quarter turn valves

Types of valve locks available

  • SQLO: Alcatraz single key integral quarter turn valve lock, locked open
  • SQLC: Alcatraz single key integral quarter turn valve lock, locked closed
  • DQL: Alcatraz double key integral quarter turn valve lock, locked open and closed.

Interlock dimensions

  • 120 x 165 x 100 mm (L x W x H)

excl. lever and bracket (depending on valve size)

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.
request offer directly
Lever valve interlock, double key integral quarter turn valve lock. Type DQL. Lever valve interlock, double key integral quarter turn valve lock exploded view. Type DQL. Alcatraz integral quarter turn valve lock

Additional service

Besides the design and production of interlock systems, we provide a range of worldwide services: 

  • Before the final handover of the interlocking system we provide a full on site training for the client. We will not leave the site unless the operators fully understand the system and feel comfortable using it.
  • On- and offshore measurement and installation on site done by our qualified installation engineers and supervisors.
  • Assistance and advice with the design of the interlocking systems, sequences and special tailor made products.
  • Periodical check up or maintenance of your safety system to keep your system up to date. 
More information about lever valve interlocks?
 

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