Valve used for Catalyst Cracker?

[Danlap]

Good day,

I am looking for some of expert opinion Re: Valve type and material (if possible) to be used in Catalyst Cracker unit.
General process condition are (Apology I am not a Process Engineer):
a. Catalyst used is some kind of sand blasting powder look alike
b. Catalyst along with other mixture velocity on 10" pipeline is approx 25,000 liter/minute. Highest process temperature is 450 deg Celcius, especially during mixing process.
At some point of the pipeline and valve, it is eroding the inner surface (due to turbulence, high velocity, powder containment)
c. For throttling purpose we use 10"-300# Gate valve Body: ALLOY STEEL 5Cr-0.5Mo; Trim in general is AISI 316/STELLITE 6.
d. Every 6 months to 2 years, valve used for throttling found to have either disintegrated trim and or even some hole in the valve body (located below the bonnet).

Highly appreciate shall anyone could provide their insights for material (body and trim) and valve selection for this kind of services.

Regards,
MR,
Valve Engineer in one of Pernis Complex Refinery

 

[moltenmetal]

Suggest you speak to whoever you licensed your FCC process from in the 1st place. They no doubt know of all the options and which works best.

Even in a solid/gas mixture like this, using a gate valve for throttling is sketchy. There are no doubt better options for flow control than this.

 

[LittleInch]

Well, at 10m/sec in your 10" line (asusming this is a liquid 25m3/minute) with fluid with hard bits in I'm actually surprised your valve or pipeline lasts that long, unless this is a batch process.

You really need to look up slurry lines and valves, but the temperature will be an issue for you. Gate valves used for throttling are very poor valves - You might want to look at V ball valves or similar, but with a powder included, anything more on the lines of a plug and cage choke valve might work - This is more like a wellhead application where a lot of sand is coming up the well.

If the throttling is fairly constant you could look at a ceramic lined long spool piece and then maybe a butterfly valve to trim the last bit for fine control.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way