Squeaking Non-Compression Valves

by Mole : 12th Nov 2008

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Issue: The non-compression valves (such as on an Andreja Premium) can squeak or creak when turning them. They may also possibly have some powdery gunk (metal flakes) noticeable on the valve body.
Solution: Take the valve apart, clean off the old grease (if any), lubricate the threads, spring and washer(s), and re-assemble. If there is only one washer, it may also be a good idea to add another, or move the existing one.

For more information, read on…

History of the Issue

I had noticed for a while that the valves on my Andreja Premium had been squeaking, or creaking, a bit. Sounded like a spring rubbing (which it turned out to be!), but it didn't bother me enough to take the valve apart to look. However, after a while I also started to notice a dark grey powdery substance collecting on top of the steam valve body, in the following location:

1_LocateCrud.JPG

I would wipe it away, but a few days later it would be back. Realising that this wasn't just dust, I decided to take the valve apart to check it out. This dark powder was almost certainly metal flakes from the spring and/or valve body wearing. The squeak was probably coming from either the spring faces rubbing, or the crud built up in the thread of the valve body.

Having cleaned it all up, I lubricated the threads and spring and put it back together. As expected, the valves became much smoother and completely quiet and the powder did not return. I expect this to be a constant maintenance item for non-compresson valves. For a quick overview of how to take them apart, continue to the Solution section below. I also suggest adding a second washer, if your valves only have one, or at least moving it to a more suitable position.

Solution

Before you begin, make sure that the machine is off and that there is no pressure in the boiler before you begin! The last thing you want is to be unable to stop the flow of steam, as can be the case when the internal circlip is removed. Once the machine has cooled off, we are OK to proceed…

The first step to curing the squeaks is to remove the cover on the front of the valve's knob. I had good luck using the sharp edge of a knife follwed by the back of the knife, once a small gap had been opened up, but do this anyway you feel comfortable. I would just advise caution so as not to damage the most visible part of the valves.

2a_LoosenCap.JPG

Once you have a little play, as in the next photo, you can hopefully wiggle the cap (or cover) out of the body of the knob.

2b_RemoveCap.JPG

Now we can see the inside of the knob, which is primarily a hefty chunk of metal!

2c_InsideKnob.JPG

In the previous picture we can see the main components. The body of the knob removes from the valve's pin, but first we need to remove the circlip and washer from the front. Your valves may not have the washer at this location. This is OK, as the preferred position is probably behind the body of the knob, so perhaps there is one at this position instead.

I managed to use a flat-headed screwdriver to prise the circlip off. You may have better luck with a pair of screwdrivers approaching the clip from each side. Once the clip and washer are removed, we should be looking at something like the following:

2d_RemoveClipAndWasher.JPG

The body of the knob should now just unscrew, counter-clockwise, just as if you are opening the valve fully. Normally, the circlip prevents the knob from being removed. You should now be faced with a spring, located over the valve's pin, with or without one or more washers (I had none here).

2e_RemoveSpring.JPG

You can see some grey gunk at the back of the spring1. This is probably where the valve was wearing a little, then the powder was working its way down the thread and out to the body of the valve as in the first picture above.

Next, we take the spring off… and clean everything up! Dry kitchen towel works as well as anything to remove the greasy grey crud. Pay particular attention to the valleys of the thread, as shown here:

3_CleanThread.JPG

Notice how much cleaner it looks. Finally, we want to reassemble everything, applying some grease appropriately (like 'Dow Corning 111' as Dave describes here: http://coffeetime.wikidot.com/e61-group-servicing). What is appropriate? I don't really know… I placed a small amount of grease on the faces of each washer, on the end faces of the spring (to prevent squeak) and on the thread shown in the previous picture.

One final thought is washer placement. The washer in my valves was placed between the body of the knob and the circlip. Whilst this position might benefit from a washer, I had also read that some people had moved the washer to a rear position, between the body of the knob and the spring. This, apparently, helped with the squeak. I thought that this position would also benefit from a washer, so managed to find a couple of spares that I could use (one for each valve).

4_Reassemble.JPG

The left hand parts diagram shows the original parts in my outer valve assemblies. The right hand parts diagram shows the location of the extra washer. I personally think that this works well in helping to reduce wear and noise during use.

To reassemble the valves, work backwards, greasing the parts as you go. Place the spring, followed by one washer, over the valve pin. Screw the body of the knob back onto the valve. Place the final washer (if you have more than one) over the end of the pin and push the circlip back on. This can be a bit finicky, but a steady hand and a flat-headed screwdriver helps to push the clip back into the recess of the pin. Finally, gently press the cap back into the knob, and you are done.

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