Aquatic Ecosystems needle valve

VaughnH

Lifetime Charter Member
Lifetime Member
Jan 24, 2005
3,011
94
48
85
Sacramento, CA
Re: Aquatic Ecosystems needle valve

The description calls it a gate valve, which is hardly the fine metering valve we need with CO2. And, being plastic it isn't likely to have a fine taper needle in it. Plus, being plastic makes it likely to eventually fail from the CO2/carbonic acid environment.

Otherwise, a great buy!! Heh, heh.
 

Bill

Lifetime Charter Member
Lifetime Member
Jan 23, 2005
124
0
16
Houston, Tx.
Re: Aquatic Ecosystems needle valve

For $10 you could go ahead and get the Clippard MNV-4K2 needle valve.

It works good, although I switched to the Swagelok on my reactor for accuracy I still use the Clippard on my mist.

Bill
 

Tom Barr

Founder
Staff member
Administrator
Jan 23, 2005
18,696
745
113
Re: Aquatic Ecosystems needle valve

The issue with plastic, thermal expansion.
Metal's thermal exapnsion coefficient is extremely low, whereas plastic is very high.

The gas cools as it's released from the tank, this and room temp changes can cause flow variation.

These valves are nice for drip applications where accuracy is less critical.

Regards,
Tom Barr