Fisher Scientific FS-100

[danielmeyer]

I purchased this regulator from eBay a number of years ago and can no longer find any technical documentation about it.
The stem and nut are stamped as CGA-320. The back of the regulator is stamped with FS-100, M, and KE.
I believe the regulator is dual-stage.

Is this unit suitable for aquarium use?

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[Matt F.]

COuld be wrong, but that looks similar to the old matheson model 8. I'm sure it will work for a fish tank. Just get the pipe fittings, the needle/metering valve, and the solenoid, and you're in business. A 8" or 10" adjustable wrench will get that post body valve off. be careful not tro scratch the body of the regulator when you remove it.

 

[danielmeyer]

Thank you for the feedback, Matt. I've been in touch with Fisher Scientific, and they had someone search the archives and were unable to locate any documentation.
I removed the post body valve with my bench vise. This regulator is exceptionally heavy.

During my most recent move, the CO2 cylinder was misplaced and my single-stage regulator was damaged (broken gauges).
I've ordered an Ideal V52-1-12 needle valve to replace my current ARO valve. I will reuse my existing Aqua-Medic solenoid.

On the weekend I'll pick up a new cylinder and hopefully this regulator will work. I'm a bit concerned as its likely very old, and I'm not sure how long it has been out of service.
Its probably not much of an indication, but the length of rubber hose connected to the PBV is still in excellent condition.

 

[danielmeyer]

I put everything together tonight to test. I turned the regulator all the way counter-clockwise, opened the needle valve, and then opened the tank.
After opening the bottle valve there was a cryogenic boiling sound that lasted a few seconds, and then a low his coming from the hole indicated.
The hissing persists as long as there is pressure in the regulator. Is there a way to determine if its the relief valve, or an issue with the regulator?

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[danielmeyer]

I checked with a couple of regulator repair shops this morning, and the best ballpark was well over $100CAD. I've opted to purchase a HPT-270B regulator instead.
The Aqua-Medic solenoid will be replaced as well because the valve body uses 1/8 ISO 228/1 fittings and adapters cost more than a new solenoid.

 

[Matt F.]

That sucks about the regulator. Sounds like it was leaking from somewhere. Could have been from the post body. check to see if there are any leaks with soapy water or see if you can feel where the gas is comming from. Make sure not to get water around the solenoid, though! (electricity and water don't mix well). The HPT270 is a rather larger regulator, but they are normally pretty reliable. It should serve you well.

 

[danielmeyer]

A small stream of gas is coming from the holes in the safety vent.

 

[danielmeyer]

Regulator Update

To wrap things up, I have received the HPT 270B regulator. The unit shipped with a CGA 580 fitting which I've replaced with a CGA 320 kit from Smith Equipment.
The AquaMedic solenoid with ISO threads has been replaced with a unit with standard 1/8" threads. The new solenoid is much cooler during operation than the AquaMedic unit.
My original CO2 setup was assembled when the ARO1 valve was a going concern, the current incarnation features an Ideal V52-1-12 needle valve.
The system is so much easier to adjust now and is very stable.

The remainder of the brass components were purchased from Home Depot.
I went to a number of specialty industrial retailers in the GTA and no one had stock, or prices, that match what is available at Home Depot.

I still looking for a brass check valve with NPT threads and some appropriate tubing.

In the tank itself, the diffuser has been replaced with a Rio 800 RVT. I haven't modified the impeller yet, but so far the new system is significantly more effective and efficient.

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[kevmo911]

A bit late in the game, but McMaster-Carr has stainless NPT/BSPP 1/8 nipples for $9/ea, and shipping would probably be about 4 bucks.