Hissing noise from isolator values

[teepa]

Hi Guys,

Is there any way to reduce the hissing noise from isolator values ? I am trying to balance the mains system so I can open a tap without the shower reducing to a dribble.
Restricting the flow from the isolator values has considerably helped, but it's come at the expense of significant hissing noises from the pipes.

None of the values are full bore before anyone asks and all pipework is 15mm except for the shower which for some reason increases from 15mm to 22mm for the last 1.5 metres.

I was thinking of getting some peglar values instead, maybe that'll help but I don't want to blow 30 quid and still be dealing with the same issue.

 

[muggles]

Fit isolators with integral flow restrictors instead, such as Wondervalve

 

[Madrab]

Isolation valves are not designed to be used as balancing valves, they are meant to be used to isolate the water to an outlet. They will always hiss, especially if you have reasonable flow/pressure running through 15mm pipework.

Why are you trying to balance the supplies? What type of system do you have? A mix of gravity and mains?

 

[sxturbo]

Gate valves should be used to throttle not ball valves.

 

[teepa]

Why are you trying to balance the supplies? What type of system do you have? A mix of gravity and mains?

It's a mains powered combi system.

Fit isolators with integral flow restrictors instead, such as Wondervalve

Excellent, looks like this is what I'm looking for. The only issue is calculating what flow rate I will need. Any tips ?

Gate valves should be used to throttle not ball valves.

8 gate values on a residential system ?? have you seen the size of those things ?

 

[sxturbo]

A 15mm gate valve isn't that big, and it is presumed they would be fitted in hidden places, inside a cupboard etc

However the solution muggles has advised is better.

 

[Madrab]

If it's a mains combi then the system will already be balanced.

Are you trying to maintain the flow to the shower if someone else uses the hot and/or cold somewhere else? If that's the case then, combi boiler power and mains flow/pressure dependent, that will be a difficult one to pull off effectively.

That being said one persons dribble is another's acceptable flow.

Combis are notoriously bad at supplying more than one outlet at a time.

 

[teepa]

If it's a mains combi then the system will already be balanced.

Are you trying to maintain the flow to the shower if someone else uses the hot and/or cold somewhere else? If that's the case then, combi boiler power and mains flow/pressure dependent, that will be a difficult one to pull off effectively.

That being said one persons dribble is another's acceptable flow.

Combis are notoriously bad at supplying more than one outlet at a time.

Yes, I am referring to the flow. I have managed to improve it substantially when tinkering with the isolation values and can get very good flows when 2-3 taps are open, the only issue is the hissing. I did some tests and below are my findings:

Current Litres/min, 50:50 hot:cold:
kitchen 10.3 lpm
bath sinktap 9.5 lpm
bathtub 22 lpm
total = 41.8 lpm

Proposed flow regulator inserts:
kitchen 4h 4c = 8lpm
bath sinktap 4h 4c = 8lpm
bathtub 10h 10c = 20lpm
total = 36 lpm

It looks like I can get even better performance with these flow inserts, get rid of the hiss and save some money in the process.

 

[Madrab]

Current Litres/min, 50:50 hot:cold

Going by the industry standards on how warm water would usually be to say have a hot shower, that would normally be around 38Deg C and if the HW at the tap is around the average 50Deg mark, using those figures the Hot > Cold ratio will be around 66%/33% > 75%/25%.

That being said, if you are getting flows and temperatures that you are happy with then fair enough and flow restrictors would certainly be the way to achieve that and minimise flow noise.

 

[teepa]

Great insight Madrab, I will re perform those tests.