Combined header tank and wave generator - solution sought

[tcs200]

Hi everyone,

My new flat has an Elson combined hot and cold water storage tank, which is about 15 years old. It's big box that sits neatly in a cupboard in the bathroom, with a ballvalve fed cold water tank on one side and a indirectly heated hot water storage tank beneath small hot water header tank on the other. The hot water side is similar to this current model.

It functions well, but when running hot water it makes an annoying noise: as the hot water from the storage tank is removed, water flows in from the header tank, the level of the header tank drops and the ball valve opens and mains pressure water flows into the header tank. No surprises so far...

The problem seems to be that, because the header tank is quite small, the incoming water sends a wave across the tank towards the float. This lifts the float and sharply shuts off the flow. The wave then quickly dies down, the float drops and the flow begins again. The header tank quickly finds a resonance where the tank sounds like a steam train pulling out of a station and the waves are big enough that, with the lid off, water sloshes over the sides.

Before I start experimenting with floats or baffles in the header tank to try and disrupt the wave or adjust its resonance, I was wondering if anyone had ever come upon this problem before, and could suggest a more elegant solution.

Thanks in advance for any suggestions.

 

[chrishutt]

Fit a float valve with a dip tube like this.

By the way that was a very elegantly written piece; you even used a colon properly!

 

[Agile]

I think his cistern uses a side entry float valve!

The solution is to add a horizontal sheet about 100 mm square under the surface connected to the arm.

This acts as a damper or "capacitance" to smooth out surface ripples.

Tony

 

[chrishutt]

I think his cistern uses a side entry float valve!

The one in the pic is side entry.

 

[tcs200]

Thanks for the advice and kind words. I'll try the baffle first (as I can do it this morning), and then the compact valve if I'm not satisfied.

Watch this space for a progress report.

Thanks again.

 

[Agile]

Yes, Chris I had not looked at it properly. However now that I have, i am not sure that it is going to be much less prone to responding to ripples than a ball float.

Lets hope he responds to say how successful the damper has been.

I did not mention before that they used to be available as an add on fitting to cure his problem but I have not seen them around lately. Does anyone know if they are still available?

Tony

 

[Softus]

Yes, Chris I had not looked at it properly. However now that I have, i am not sure that it is going to be much less prone to responding to ripples than a ball float.

I won't be less prone, but, owing to the dip tube, there won't be any ripples.