sanitary ball valves / flushing cavity ?

[ekos]

Sitting here trying to find a good solution for a sanitary valve, to be used in waterbased paint production. Our concerns is how to avoid bacteria contamination. I have seen some valves that have ports for cavity flushing, also some options with cavity fillers.

Is there anyone that can advice me about pro's ,con's or alternatives.?

Advice regarding manufacturers that have good solutions for this type of challenge ?

 

[gerhardl]

Only some ideas, based on valve knowledge and summer job as a student as process worker in a paint producing plant many years ago:

Any ball valve used in painting producing will be difficult to clean properly because of hidden hollows, edges, sealings etc.

You do not mention sizes, temperature and pressures, but:

- Membrane valves ('Saunders' or competitors (many)) with membranes suited product and cleaning agents (available in many elastic materials and body inner surface coatings, including membrane and body in all SS.

- You have of course the range of 'pure' sanitary valves used in the food,diary and medical industry, but apart from high cost, I am not sure theese would be ideal including the usually incorporated CIP system if sticky/drying painting components go through the system.

- Possibly perhaps excentric plug valves (?)

- Possibly V-port ballvalves with shell-formed 'ball' (?)

- Cheapest, but not complete sanitary, and with possible wear (abrasion) of stem seal material, upper class construction of Y-type seat valves, perhaps with rounded (regulating) plug and scraper for stem included in front of stemseal sealing stack, long support of stem through long or several stem bearings.

 

[JimCasey]

Regular ball valves have a cavity around the ball, between the seats. It flushes somewhat at partial valve openings.

You mentioned cavity fillers. These give you less volume to purge, but long, deep crevices that are difficult to clean.

You did not mention a cutaway ball. Instead of being a sphere with a hole thru it, the ball is cut as a "C". The cutaway greatly increases the amout of cavity flushing.

V-Ball type control valves are similarly cut away. If you are just looking for a small manual or on-off valve, at least Worcester offers the C-ball.

 

[HEC]

For best solution do not use ball valve. A lot of manufacturers claim to have a sanitry ball valve but I am yet to be convinced.

As Gerhardl reccomends a diaphragm valves is the best solution for sanitry application. Other options are piston valves as supplied by tetra pak, alfa laval, or APV etc...

Mark Hutton

 

[SteveWag]

Diaphragm valves, hands down!!
Steve