what kind of valve we should chose to install automation & batching system 2

[ronissa]

I am working in a chemical company and we decided to install automation & batching system for our production line that involve mixing 5 or 6 kind of liquid raw materials for making polyurethane product mainly.
we have installed load-cells on our agitator tanks and our raw material tanks to weigh them. the purpose is to pump the materials automatically to agitator tanks and stop the pump and close the valve by PLC programming by the feedback of the load-cells .please help me to chose the suitable valve for this project.each batch contain about 12 tons of material

 

[MJCronin]

This might help ...

All of the major valve types (e.g. gate, globe, butterfly etc) have advantages and disadvantages regarding operation, cost, maintenance and control of flow.

IMHO, the valve suitability for the particular process service is independent of the method of actuation (manual vs. automatic).

In other words, you should be selecting the same valve regardless of the method of valve control ....

MJCronin
Sr. Process Engineer

 

[adammal44]

You need to review your specific application with a valve vendor. Some of the tradeoffs of various valve types:

i.) Flow Throttling: Some valve types (globe/needle) allow for fine throttling of flow from 0-100%, others are more open OR closed with little ability to throttle flow.

ii.) Leakage: Some valves are more prone to leakage than others. How difficult is it for you to maintain your valves in-situ vs. how much leakage can you tolerate?

iii.) Fluid type: Do you need valves appropriate for food-grade fluids? Are you dealing with caustic chemicals? Some valves have seating materials that are not appropriate for all fluids?

iv.) What pipe code are you designed to?

 

[Compositepro]

You probably should be looking at sanitary valves and fittings. These are primarily designed for food and reactive chemical service where piping systems must not have dead volume and the materials tend to build-up on surfaces in the pipes, so the pipes must be cleaned periodically.

https://www.dixonvalve.com/division/dixon-sanitary

 

[Latexman]

Sorry, I was unable to post yesterday due to some computer problem.

We have a similar sounding application. Not sure how similar because of the lack of detail. But, we use a ball valve with actuator and positioner. The valve is used in three modes - open, "dribble" (~10% open, but this is adjustable for each valve), and closed. There is also preact for the drainage, but that is not dependent on the valve type.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[ronissa]

thanks a lot Latexman
could you give me some more details about your experience usiung this kind of valve?
please tell me more about positioner and actuators

 

[Latexman]

The biggest three benefits we see is it works accurate enough, we have a tight shut-off valve that works for quite a long time between repairs, and it's in-expensive. We have over 25 years of experience with this set-up. The actuator is mandatory. The positioner is optional; it helps accuracy and repeatability. I have no intention of educating you on the details of actuators and positioners, because that is not my strength. I rely on others to specify those.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[ronissa]

thanks