Frequently asked questions
How does the interlock tagging work and what are the design parameters?

The tagging on our products, keys and dust caps has a preliminary important purpose. To help operators in the field, during change over, to correctly identify the next step in their procedure or sequence. Furthermore, it shows relevant information on the lock, keys an the steps in the procedure. The key that is present in the control room tells the operators the status of any particular system. 

Alcatraz Interlocks can supply the tagging on the key and dustcap in multiple colors. Up to 3 lines of 13 characters. 

Can Alcatraz Interlocks help us with the determination of a viable and safe operating procedure?

Alcatarz Interlocks can act as a consultant and advise on the correct operating procedures on almost all critical processes. Due to our extensive experience gained in over 20 years. 

What is a valve interlock?

A valve interlock is a single- or dual-key assembly which locks the valve in two positions - open/closed - with one key trapped within the lock assembly and one key free.

How do valve interlocks function?

The mounting kit connects the rotating part of the valve, spindle or stem, with the rotating part of the lock and or the bearing.

The kit connects to the static part of the valve, top flange or bonnet, with the static part of the interlock (body). Both parts are designed and manufactured to that particular valve. 

How are valve interlocks manufactured?

The valve interlocks are manufactured after the design work is completed. The design works are based on the dimensions of the valve top works: yoke, stem, hand wheel connection, spindle, packing gland etc.

We manufacture our mounting kit (designed bracket) from AISI 316 stainless steel only.

How are the valve interlocks installed?

To install an interlock, the existing handwheel or lever is removed from the valve. Then the mounting kit is bolted onto the valve. Our interlock is fitted on the mounting kit. 

As a standard we replace the original handwheel or lever with our own handwheel or lever. This new product does not change the original characteristics of the valve. Our new lever is standard AISI 316 stainless steel, the hand wheels are Zinc coated cast iron.

What about the existing handwheel or lever?

If there is a desire to keep the original hand wheel or lever, Alcatraz is able to produce hand wheel and lever adapters allowing to refit the original handwheels and levers.

What are the design requirements Alcatraz Interlocks need from us to provide our company valves with an interlock?
Alcatraz requires the detailed dimensions of the top works from the valve to design and manufacture the custom made mounting kits. Our dimensional requirements are requested using our standard fill-in sheets. If the valve in question is significantly different from the standard valves on the sheets we will maintain close contact with the client to make sure we get the requirements to do our engineering.
Is there any impact on the valves' integrity?

No welding or grinding is done to the valve nor are any infringments made to the pressure containing or presurre retaining part of the valve.

Can Alcatraz Interlocks be mounted on any type or size of valve?

Of course we can. We have 4 standard types of valve interlocks: DML1, DML2, SBL, for handwheel operated valves (gate, globe, gear operated) and ball valves. And a DQL for lever operated valves. 

The mounting kits are custom made to the top works of the valve. So Alcatraz can design a solution to fit on any type or size of valve

What happens in the event of losing a key?

Should you lose a key and you don't want to keep using the Master key, within 5 minutes you can have your new key. 

How can you do this within 5 minutes? We supply you with a full emergency kit full of all the spare parts, key coding and special tools to make and reproduce the original coded key. We can als ship keys at short notice. 
In order to use this emergy kit we train the supervisor to replace keys within minutes.  

What are the standard materials used for manufacturing of Alcatraz Interlocks?
All bodies and all components are stainless steel AISI 316. This is the Alcatraz Interlocks standard.
How many different key codes can Alcatraz Interlocks manufacture?

Alcatraz Interlocks has over 25.000 different codes available. We can easily supply unique keys for any project.

Who installs the locks?
We do advise to make use of our team of installation and service engineers. Especially on large projects we advice to at least have supervision or commissioning by an Alcatraz Interlocks supervisor.
We have a dedicated team (also local) of maintenance professionals who can carry out the installation and commission of our interlocks and measurements of the top works. 
Do you use grease in your design of interlocks?

The answer is no, we have eliminated grease. We use the special NCS-30 Artic Nonconductive Thread Compound carbon fibre. All our components are dry movement parts and only have a PTFE glaze.

Grease can only attract dirt and get dried out so this is a significant improvement compared to other locking suppliers. 

Can Alcatraz Interlocks execute large scale projects?

In the last few years we have handled several projects with more than 14.000 valve interlocks used. In most cases we also provided the on site service, training and commissioning.

Are Alcatraz Interlocks fire safe approved?

The Integral Multi Turn & Integral Lever lock types from Alcatraz Interlocks were thoroughly tested and Alcatraz was awarded with the Fire Test Certificate, in accordance with ANSI/API Standard 607, 6th edition, September 2010 standards. Customers can be assured that even in the event of a fire the interlocks will function safely as designed.  

Alcatraz Interlocks are designed to withstand temperatures of 1000°C+. 


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Stedenbaan 6
5121 DP Rijen
The Netherlands

Phone: +31 76 514 7172
Fax: +31 76 522 5296

Safety by design