use of air for valve activation in solvent room 1

[Pipeline1972]

Good morning everyone,

does anybody know if the use of compressed air, for activating diaphragm valves, in a solvent room is somehow regulated?

Typically, we'd use compressed air for diaphragm valves, but in a solvent room, we might want to use nitrogen instead, to avoid a mixture of air with flammable liquids, in case of diaphragm leaks.

Thoughts?

Process - Piping
ing - EiT

 

[JLSeagull]

The question expresses an opposite concern than I would express. The HAZARDS of VENTING NITROGEN from valve actuators and accessories in a closed room are VERY SIGNIFICANT. Assure adequate ventilation in the solvent room. Use air for the ventilation. Perhaps consider fire suppression. A review would require details such as the volume of the room, what solvents and the solvent volumes.

 

[Pipeline1972]

sorry, i don't know why i wrote "valve". I meant diaphragm pumps....
But your comment is helpful anyway! Thanks!

Process - Piping
ing - EiT

 

[stookeyfpe]

Does your solvent room have a mechanical ventilation system? Also, why not use plant air? What are the pumps supplying?

 

[Pipeline1972]

Hi Stookeyfpe,

Pumps are used in solvent dispense modules, and yes the rooms, and modules are ventilated.

Concern with using air: possibility of mixture of air with flammable liquids, in case of diaphragm leaks. One major semiconductor manufacturer uses nitrogen to avoid this.

We are wondering if this could be a code requirement..

Process - Piping
ing - EiT

 

[stookeyfpe]

Why are you worried about air mixing inside of enclosed diaphraghm? So what if if some air gets in - the mixture will be so far outside the flammable range that ignition is a fairly low probability incident. I don't know enought about your pumps but with the mechanical ventilation I don't think you have an issue.

The use of air or nitrogen is not an issue from a code standpoint. Under the NEC pnuematic equipment is one means of complying with the HAZLOC requirements, and I prefer it given the number of times I've seen it improperly installed by commerical electricians who have limited experience.

Now if your dealing with something funky that can exhibit pyrophoric characteristics (you indicated semiconductor), or other organomettalics, then I would recommend N2.