Water hammer from unvented cylinder

[Taconite5]

You were seeing 8 bar on a (the) PG installed near the washing machine, do you expect 8bar there or can you put another PG on there again and note both pressures. Or you could remove the arrestor at the IGV and connect the PG directly here to see if you still get only 3.0/3.4bar or whatever.

Hi, I’ve done that before. Near the ICG it’s never spiked more than 5.

 

[Johntheo5]

Hi, I’ve done that before. Near the ICG it’s never spiked more than 5.

Are you still getting 8bar near the washing machine T off?, if so, maybe another arrestor here.

 

[Taconite5]

Are you still getting 8bar near the washing machine T off?, if so, maybe another arrestor here.

Not since I put the PRV in. More like 4.5 during a spike now.

 

[Johntheo5]

Not since I put the PRV in. More like 4.5 during a spike now.

Well, if you're pretty sure that the mains pressure is 4.5bar then those pressure spikes are normal enought IMO, I'd still like to see the ICG NRV operating "normally", not with a zero dP, but looks like you would have to remove the upstream PRV to achieve this.

I can't find a exploded view of a ICG to see the check valve in this but imagind its spring loaded to avoid chatter even under normal conditions.

 

[dilalio]

Remove the ICG and give it a rinse.
Make sure no aliens caught in NRV and spring pushes dome back into housing.