Chromatography Forum

We have found a problem with some of our hydrogen gas cylinders. The wheel tap is sometimes so tightly shut we can't get it opened. As the leader of a team of aging chromatographers I was wondeing if anybody has seen a tool for this job.
I am worried about the risk of injury to my team as there is a bit of machismo positioning going on about who can get the tap open. I am reminded of scenes of people (men) trying to get pickle jars open!

GCguy

A shifting spanner or large pipe wrench will do it, but you run the risk of snapping the top of the valve off. Having been in labs where I was the only male (dream on guys) I found that the best technique was to return such cylinders to the suppliers for a replacement and demand either that they indemnify our lab against damaged valves or make sure that all the taps would turn before they delivered.

Peter

Hi,
We've used a special tool made by a local welder at the first lab i've worked for. They were essentially cut from a suitable pipe and steel segments to fit the wheel tab were welded inside the circumference, as well as a rod as a lever.
Best regards,
Bulent

And if one has the type of fellow in the lab which I occassionally encountered, he uses this fine special tool to turn the valve to the right when it should be turned left.

Talk to your cylinder supplier customer services department. Newer cylinders have different valve seat systems, and over-tightening will quickly damage the seats. Here, they come with express warning label to not over-tighten.

Our local supplier also had a softer plastic handle that fitted over the metal handle, and provided much better grip - along with slightly more leverage. Worked well for us, and I note that some gases now have a similar permanent polymeric cover on the cylinder valve handle.

We recently had the experience of the valve on a medium-sized cylinder of anhydrous hydrogen chloride fail a few minutes after being opened in a fume hood.

Very impressive. Totally destroyed all of the equipment in direct line, noise was impressive, as was ice buildup on bottom of cylinder until we managed to close the valve. Really good test of fume hood boost setting. Cause was probably under-tightening previously - allowing a slow leak to dissolve the seat.

Please keep having fun,

Bruce Hamilton

Bruce,
How many pidgeons died near the outlet from your fumehood? Or is the outlet scrubbed?

I once worked with big cylinders of anhydrous HF. Didn't really worry me at the time, but looking back the failure of a valve would have been catastrophic. There was an incident when about a litre was spilt onto the floor. Fortunately everbody was in air-fed acid suits. The windows in the lab all had to be replaced!

Bruce,
How many pidgeons died near the outlet from your fumehood? Or is the outlet scrubbed?

I once worked with big cylinders of anhydrous HF. Didn't really worry me at the time, but looking back the failure of a valve would have been catastrophic. There was an incident when about a litre was spilt onto the floor. Fortunately everbody was in air-fed acid suits. The windows in the lab all had to be replaced!

It's not called "windy Wellington " without good reason - a vigorous breeze was blowing. Not scrubbed, but no residential building for 100 metres or more , and adjacent gardens/lawn showed no ill effects.

I also worked with HF, and always concerned, fortunately only spills were in fume hoods.

One of my bigger concerns as an industrial chemist was when an electroplating tank "lost" 1800 litres of 150 g/L cyanide overnight down the trade waste drain - when most drain waste was acid metal pickling solutions. Lots of dilute caustic immediately dumped, don't think anything died, management was mainly concerned about the cost of the lost dissolved zinc....

Local authority was always repaired their monitoring pH meter, because it would swing wildly, producing "unbelievable data". They were truly the bad old days for the environment....

Bruce Hamilton

And where I work, after much heated argument, I've finally gained permission to dispose of up to 500mL 0.1% formic acid per day into the drains, and even to put this into writing.

There were concerns it might unduly affect the pH or total organic content of our waste.

I'm keeping a straight face. Honest.