Rugosity spec for GMP Valves

[therunningbruce]

Please delete if not ok to ask:

All the literature I can see (and the info ) from valve vendors (Ive found so far).. is that rugosity of GMP valves is always 0.8 or less.

A chemist in our organization has asked can we get lower , say 0.5 . We have some drivers for a lower spec for quality..

In engineers experience are these spec list (0.5) are commonly available. ..

i want to check if what we are asking is bad idea and we should just clean the system more effectively...

 

[1503-44]

That property is not specified for commonly available valves.


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

Translation.

Rugosity or Ra - basically a form of roughness or roughness by arithmetic average says google, measured in microns.

0.8 microns looks to me like near mirror finish, so 0.5 is basically a mirror.

GMP - good manufacturing Practice - a term used in the pharmaceutical industry to mean something which doesn't get contaminated to hold bits of the previous process and can be easily cleaned.

You need to ask the vendors.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Texas Piper]

You didn't specify what type of valve or service, but look through the GEMU catalog. It looks like they have valves that fit your RA requirements.

 

[therunningbruce]

thanks for the advice.

it is for a cosmetics type duty.

 

[MortenA]

@1503-44,

since you seem to work in the O&G business whats uncommon here may not be so in pharma

@OP, its funny having to say this in these days, but did you try google yourself? Well GEA seems to make some butterfly-like valve with Ra<0.5:

https://www.gea.com/en/products/pum...containment-valves/buck-containment-valve.jsp

I work i food additives, not as strict as pharma so i dont think we consider this parameter.

--- Best regards, Morten Andersen