Last month I got an email from a colleague valve expert working for a major valve company stating, “We no longer publish our Actuated Valves (AV) torque data because of its abuse by the competition…” When discussing this with my partner in crime, Kees Meliefste – Global Technology Lead Automated Valves at Dow Chemical, he confirmed that he received this same statement from several other major valve companies as well. When he was asking and pressing to get quality torque data, he even got the comment back “Ah, you want technical torque data and not commercial torque data…” In other words, several major valve companies take this position!
This is totally unacceptable and please, authorities and industry, please take appropriate action! For those unaware, we predominantly use AV assemblies as safety devices in our industry as ESDV (Emergency ShutDown Valves) and/or BDV (Blow-Down Valves). Those assemblies play a crucial role in mitigating potential incidents in our industry. We have installed and continue to install millions of those AV assemblies in our industrial plants to protect people’s lives, to protect our environment and to protect the integrity of our installed equipment.
AV assemblies are comprised of three parts. One – the valve – predominantly a part-turn rotating valve such as a ball valve, a butterfly valve or a plug valve. Two – the actuator – predominantly a pneumatic or hydraulic actuator providing the required power (the parameter needed to measure is called torque) to move the valve to its safe position on demand. Three – a mounting kit – to put the valve and the actuator together into an assembly.
To properly size & select this AV assembly it is essential to know what torque the valve needs to move it on demand to the safe position, in order to select the appropriate actuator and for correct mounting kit dimensioning. Crucial is to find an actuator large enough to provide the torque the valve needs to move on demand to the safe position, but not too large to risk damaging the
weakest link of the drive train!
The bottom line is: We need to know the valve torque on demand! At first glance one would say: what’s the problem? The end user precisely specifies the on demand conditions and the valve manufacturer does his or her homework to come up with the required on demand torque value. Unfortunately, there are too many hurdles resulting in no torque data or poor quality torque data!
Often organizations purchase valves as commodity items by focusing on only the right valve for the given fluid conditions,but do not focus on the torque needed on demand. Those of us asking for torque data are often seen as a nuisance for the valve manufacturer. To quote a CEO of a major valve company a couple of years ago at a major valve conference: “Henk, you are always asking us for torque data, but do you realize that when I sell 1000 valves, only 1 (he was provoking me) needs an actuator! So you understand where my priority is!”
Unfortunately, players in this field; manufacturers, engineering contractors, valve automators and end-users are not speaking the same language! Consequently, we are not- or mis communicating and creating more issues than help to realize what we need: We need to know the valve torque on demand! Unfortunately, device certifi cates are generated and utilized to satisfy IEC 61508/61511 standard requirements, without even an attempt to address what we need: We need to know the valve torque on demand!
Unfortunately, there is no international standard (yet) enforcing valve manufacturers to provide what we need: We need to know the valve torque on demand! It is fair to say that often end-users have not properly specifi ed in what conditions those assemblies have to function. One – we need to specify how frequently we operate these assemblies! For those not aware, today we run steam cracking plants for 10 years without a turnaround. We may have valves in there that are standing still for those durations! Two – we need to specify the fl uid conditions. Not everything that goes through a valve is clean and lubricating. We need to specify cryogenic conditions if it is the case. Three – we need to specify the environ-mental conditions. Lastly, we need to know the full set of process data and application characteristics. Often this is an important missing part from the end-user. They are dropping the ball in this respect!
In this journey, which I started a dozen years, and which I expected to take me not more than a year or two, I did not make a lot of friends! But this is not preventing us from persisting and continuing until we get to know the valve torque on demand!
We are a consortium of end-users out of the petrochemical, chemical and oil & gas industries. We are constantly caucusing with our colleagues in other industries such as the water industry and the nuclear industry. We came up with end-user guidelines to create awareness among the various players in this field. We tried to get it endorsed by international standardization organizations,
but did not succeed.
Finally, over the last 4 years we developed an end-user driven AV Assembly Recommended Practice (RP) focusing on handling AV Assemblies as Engineered Products, no longer as commodities, with input from almost all key players in this field. It addresses
all the pitfalls mentioned above. It became a 53 page comprehensive document. We conducted more than a dozen seminars, workshops and webinars around the globe to debate, discuss and adjust what is required to get the valve torque on demand to correctly size and select AV Assemblies.
We will release this AV Assembly at the upcoming Valve World Americas event in Houston this coming June. A final workshop is scheduled to debate and discuss this final AV Assembly RP. So, authorities and industry, pick up the ball and get it rolling, before it is too late! All involved parties, i.e. authorities, certifying bodies, engineering contractors, automation centers, valve manufacturers, actuator manufacturers, let’s do it together!
About the Author
Henk Hinssen is an instrumentation engineering associate, working for the process industry almost 40 years, of which 20 years for a major petrochemical company with HQ in Texas. Henk has been involved with Valve World since 2005 and has moderated workshops in Europe, Asia and Americas. Henk is a member of WIB Final Element WG from 2005-present and is a key contributor to the development of Ri & CAT.