Service is Sour Oil and Gas mixture (Presence of Sand) 2

[bmoorthy]

Sand level in the process fluid is 250 PPM. Fluid is sour Oil and Gas mixture.

1)Does the ball and seat require Tungsten Carbide coating?

2)What are the criteria to select Tungsten Carbide coating?

3)Are there any less expensive alternatives for TC?

4) Suppose one compares x750 or 718 material versus TC coated 316L in the above application, which is better?

 

[BigInch]

A ball valve is not for throttling, therefore it should be 100% open and not really subject to sand wear on the ball exterior or seats. Sand should be flowing through without impinging on the ball surface as it would in an open condition.

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[bmoorthy]

That was simple and smart reasoning.
Thanks for sharing your view.

 

[BigInch]

Happens a lot.

Now I suppose the question is, do you need throttling?
TC is hard and wear resistant, so you might need to specify that or a similar material for your throttling valve, unless you can install an orifice plate (in an easy to access and replace location) to take the pressure cut, with a sand trap in front of it if needed.

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[JLSeagull]

I sometimes consider hard facing valve plugs and seats with Stellite Alloy 6 or a suitable N08367 alloy in high wear applications. Stellite 6 is a cobalt based alloy that resists wire drawing when operating near the seat; and provides some resistance to errosion caused by entrained sand in oilfield production. Stellite performs well in many harsh chemical and severe temperature applications. I don't know how it compares to tungsten carbide coating.

 

[Ashereng]

Depending on pressure and temperature, a "rubber" pinch valve may work. They don't react with H2S, and is good against abrasion.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[JimCasey]

You jumped 'way past every application parameter and landed on a WC coated Ball valve. Let's go back to the beginning:

What is the temperature and the pressure? Is this a throttling valve? If it is, what is the downstream pressure. What size line, what schedule, and what flowrate? Does it have to shut off to zero observable leakage or is some amount of dribble either expected or necessary?

With sour service you need NACE materials. Most of the hardened materials do not meet NACE specs, which frequently specify allowable maximum hardness limits for specific alloys. Some hard alloys do meet NACE, but your valve supplier will have to certify each part and it's a good idea if you know what is acceptable.

The right answer for the application could be anything from the rubber pinch valve mentioned earlier to a rubber-lined butterfly valve to an all-ceramic ball valve or even a WC and ceramic angle-type globe control valve. Define the application.

Oh, and BigInch: There ARE ball control valves and they work very well when applied properly. Your statement is correct if interpreted that one does not just grab any ball valve to use it for modulating.

 

[BigInch]

Jim, Take it easy. What's the problem? I didn't say they wern't special pattern balls. Heck maybe there's a special reverse acting check valve too, but unless you buy a special pattern, balls ARE made for on/off. OK I just guessed its a gathering system from the header [2 phase, sand, oil, gas, H2S], so I wouldn't want to use a "special" anything in/near a gathering system, where they probably don't need to be throttling something anyway, never mind with a rubber lined special pattern ball control valve. He didn't say it was hot, but all wells are hot these days, so the rubber would probably melt too. If I wasn't worried about all of that, I'd still have to worry about somebody just walking off with an expensive, special pattern, rubber lined, ball, control?, valve left out in a gathering system. All in all I'd just make sure a normal, plain old, cheap, easy-to-replace-if-necessary, ball valve was either open or closed and leave it at that. IMO.

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[derf99]

I have a sand problem with CO2 flood. The wellhead effluent is at moderate pressure (4-600 psi) and still contains liquid CO2. There is sand present that is becoming a problem. What valves will stand up to this service, and how to remove the sand without making dry ice?

 

[Ashereng]

derf99,

You should start a new post with your questions.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[tsenthil]

Dear Moorthy,

With our experience on Sand service, there is no comparison between stellite 6 and Tungsten Carbide. So far we have experienced that the Tungsten Carbide coating is the best solution for Throttling Sand Service.

If the service is cavitating or Flashing, please select a Globe or Angle Control Valve with multi stage Anti Cavitation Trim with Tungsten Carbide Inserts.

I Believe even a V Notch Ball valve with Ceramic lining can also be used for throttling service.

Also important to note is though Tungsten Carbide is very hard, it cannot withstand sand service for ever. For a typhical Cavitating Throttling Application, Tungaten Carbide Trim will withstand for a maximum of 2 Years only.

 

[bzandy]

I am quite agree with tsenthil that the ceramic lining is a good alternative to TC since ceramic lining has an excellent performance in the anti-wear application. However, the real ceramic valve manufacturer is still few available.