INFORMATION ON ELECTRICAL ACTUATED BALL VALVES

Jaime Martinez

Company: Sorry. You can't expect an answer to that question in a public NG.

Title: Senior Process Controls Engineer

Dept: Automation

or used at your business/plant?

I work for an engineering company and have specified many electrically operated ball valves over the years for many clients in the petroleum and petrochemical industries. You earlier mentioned "electrically actuated" now you say "electronically commanded". These are not at all the same thing. The majority of our "electronically commanded" ball valves are pneumatically actuated.

We generally specify the valves and the actuators separately. Perhaps you should tell us what size valves you have in mind. For 1" and less I generally use Whitey. From 2" to 52" it depends a lot on the application. What pressures do you have in mind? I have used from 100 to 4000 psi. They are definitely not the same brand. I could get this information but it would take a bit of work.

commanded ball valve controller/positioners at facility?

The fluid commanded by the controller/positioner is usually air. That's what drives the actuator.

However, I think you mean to ask what type of fluid is controlled by the valve itself. That is usually oil, water or natural gas. It can be a mixture of all three along with steam, sand, and small gravel.

If the valve doesn't open on command, the process won't work. If it doesn't close on command we will have a major economic and/or environmental disaster. I recall one particular failed ball valve that resulted in flames that could be seen 90 miles away. (It was at night.)

In general, no, although I've had several startup problems. The first was due to incorrect grease in 3500 psi water service. The operators did not understand that water needs different kinds of grease. The second was dirty instrument air; the pilot valves got stuck.

Compared to what? I'm getting the impression I'm doing a homework assignment here. I love to mess with young minds.

ball valve controller/positioner?

Controllers, positioners and actuators are three entirely different things.

- An actuator moves the valve.

- A positioner senses the actual position of the valve and makes adjustments to the actuator to accurately place it where needed.

- A controller compares the value of some process variable, such as flow rate, and produces a signal that tells the positioner where to position the valve. Incidentally, positioners and controllers apply to continuously regulating valves. Ball valves are almost never used in regulating applications. They are not very good at it. Ball valve applications are almost always on/off, however there are specialized variations such as 'V-Ball' and 'Q-Ball' that are somewhat better at regulating

As for features, very simple: I want a valve and actuator that reliably opens and closes on demand regardless of all other factors. I use them most often in safety applications.

$500 to $1,500,000 each.

I would guess that the world of ball valves is rather larger than you expected.

Walter.

----- Original Message ----- From: "Walter Driedger" Newsgroups: sci.engr.control Sent: Monday, September 29, 2003 9:10 AM Subject: Re: INFORMATION ON ELECTRICAL ACTUATED BALL VALVES

Here's another one - we used some RCS actuators on a pipeline in Perth and had major condensation problems inside the actuator case - one actually shorted out on us - and in a hazardous area too!.

It's a good idea to *make sure* that the actuators are fitted with gaskets/o-rings and not just take the manufacturer's word for it.

Hehe :-)

I'd like one that *always* stops on preset torque/position without relying on flimsy limit switches that eventually move out of adjustment, destroying thousands of dollars worth of DBB valve slippers in one go.

Same here.

Cameron:-)

I wish more people understood this. I've had to work with equipment in which ball valves were used to regulate flow, and needle valves were used for on/off control. To top it all off, they would put round handles on the ball valves so they would look the same as the needle valves. I suppose that is better than mounting the ball valve so that the handle has to be raised to turn the valve off, but not much.

It took me quite some time, and a lot of meetings and discussions to finally get them to do it properly. They must have thought I was a pretty tough nut because I wouldn't allow the wrong valve style to be used, and strictly enforced a standard that it should be readily apparent to a distant observer which valves were open and which were closed. I felt that it was important, because the equipment could be used several different ways, and it was very important to figure out which way was being used before any adjustments were made. I don't think standards existed at that site before I got there. I'm pretty sure there aren't any now that I've left.

Michael

Where I come from motors are equipped with anti-condensation heaters. When the motor is off, the heater is on. It doesn't have to be hot, just a degree or two warmer than outside.

Walter.

On actuators? I can safely say that I've never seen that over here! Maybe it doesn't get "cold" enough.. supposedly.

Cameron:-)

"Walter Driedger" wrote in news:TTJdb.28544$O85.15245@pd7tw1no:

Excuse the "decloaking" (unlurking?) to take exception to your comment about Ball Vaves not generally being used for modulating service.

The Fisher V-25 / V-250 is a "full ball" (not a segmented notched ball) and has been used for years on Pipe Line applications; The Neles (now Metso) Full Ball products have been used as Modulating and On /Off devices for 30 plus years in the Pulp Industry. Even Jamesbury (now Metso as well)has a "huge" installed base of Reduced Port Ball Valves in Modulating service on Pulp, Water, Steam etc.

I do agree however that "cobbling" product together with one manufacturers Ball Valve, Some One Elses Actuator and a Third Vendors Positioner is only asking for trouble.

You identified the two I had in mind.

Walter.