does increase to steam pressure exacerbate existing pipe banging?

elfie

have a system with pipe banging issues.  does a higher than necessary steam pressure level make the velocity of water movement causing the banging to be more violent where pipe damage is more at risk?

BobC

Keep pressure low

High steam pressure can cause many problems to be worse than they would be at low pressure and low pressure saves fuel.



What problems are you having? Post pictures of your boiler and the pipibg around it.



Bob

Dave in QCA

Same Boiler as Before?

If this is the same boiler system that you have descibed before, I recall that you have a place or more where the condensate is lifted by steam pressure.  In these cases, low pressure will make it bang up a storm.  The pressure must be maintained as designed.



In other cases, as Bob said will be made worse by high pressure.  Such things as leaking steam traps, if the pressure is raised will leak even more, thus mixing lots of steam and condensate in your return lines and thus, lots of hammering.

elfie

low steam pressure

part of the problem is the boiler service firm increased pressure settings to range from 5 psi to 7.5 psi without really understanding system - they tend to set other steam systems at these higher pressure levels so it made sense to them to do it and seemed to have abandoned modulating control capabilities (settings were changed from levels of 2-4 psi as done in prior yr, and no heating problems in prior yr, and modulating controls were set in prior yr to reduce burner to extend firing cycle; firing rate is now set to highest level with no modulation).



since boiler is substantially oversized, what is now happening is lots of short cycling at this higher pressure setting (ie. pressure at higher setting seems to be lost more quickly than lower pressure settings, which makes sense)



the reason for pipe banging is due to zone valves in system that require pressure to drive water out of the mains. the existing condensate return piping is slightly higher than the end of main traps. so condensate gets left in mains when zone valves close (not really practical to install a condensate return pump).

Dave in QCA

Why did they raise it?

Did they say why they needed to raise the pressure, or did they just do if?  The reason would be interesting as it might point to something that we are otherwise unaware of.



However, if in the past it worked at the lower setting, than it will still work I would think.  Regarding the hammering that happens when the zone valvels open and water must be pushed out of the main, it is going to hammer no matter what.  With higher pressure, the hammering might be louder, but last for a shorter period of time.



Based on what have said, if I was running the system, I would put the pressure back where it was last year.

elfie

louder hammer

thanks,



to me, a louder hammer means that velocity is more aggressive with increased risk of pipe and/or trap damage.